Mountain Weather

Crib y Ddysgl weather forecast.

1,065 m summit in Eryri (Snowdonia). 8 forecast days covering wind, cloud, rain and temperature, updated 4 November 2026 at 16:25 UTC.

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Confidence: Medium
Overall hill weather42Poor
Summit wind · 08:00-17:0015-35 mph easterly Summit gusts · 08:00-17:0040-50 mph Feels like-8 to -4°C PrecipitationLittle or none Cloud-free summit estimate40% Cloud base through day600-1,400 m Freezing levelAbove summit DaylightSunrise 07:19 · Sunset 16:39 · 9.3 hours daylight

The day on the hill

A poor day on the tops of Crib y Ddysgl, with a blustery wind and cloud coming and going on the summit.

Wind

On the summit expect an easterly wind of 15–35 mph for most of the day, with gusts of 40–50 mph at the windiest. Lower down on the open hillside it will be more like 5–15 mph. Gusts like that are strong enough to make walking into it hard work, with buffeting on ridges and edges.

Cloud and visibility

The tops are likely to drift in and out of cloud, with the best chance of a clear summit in the early afternoon. The cloud base could be as low as 600–900 m around midday. In cloud you'll be finding your way without landmarks, so carry navigation you trust and know how to use, with a backup such as a spare battery or a map and compass.

Rain and ground

It should stay dry.

Warmth and kit

On the tops it will be around 0 to 4°C, feeling like -8 to -4°C in the wind. The freezing level is above the summits. Take a hat, gloves, a windproof and a spare warm layer.

Daylight

Sunset is around 4:40pm, so allow time to get off the hill before dark, and carry a head torch.

Forecast confidence

There is some disagreement between forecast models on wind strength. Things could still change through the day, so keep an eye on the sky.

Sunshine context Model-grid estimate, not summit sunshine

The surrounding model grid indicates 2.5 h of sunshine. This is not a forecast of time in sunshine on the summit. Use the cloud and views outlook above for the conditions on this mountain.

Cloud may obscure this summit even while the surrounding model grid indicates sunshine. The low cloud-free summit estimate is a reason to be cautious about expecting views.

Early
Less than 1 hour
Midday
1.9 h
Later
0 h

Overnight forecast: 17:00–08:00 (UK local time), in Wild camping below.

Morning · 08:00–12:00 Poor Summit winds around 25-35 mph. Gusts around 40-50 mph are possible on exposed ground. Gusts this strong can make walking into it hard work, with buffeting on ridges and edges.
29
Afternoon · 12:00–17:00 Mixed Summit winds around 15-35 mph. Gusts around 35-45 mph are possible on exposed ground. Gusts this strong can make walking into it hard work, with buffeting on ridges and edges.
54

Compare an early start with later conditions. The main forecast above covers the day in more detail.

Overnight · 17:00–08:00Wild campingBetaToo windy for an exposed pitch above about 600 m (gusts of about 50 mph). Lower down, a poor night to camp on open ground. 19Poor · 600 m View detailsHide details
Night beginning Wednesday 4 November 2026

Full overnight outlook

Too windy for an exposed pitch above about 600 m. Lower down, a poor night to camp on open ground. Gusts reach about 50 mph around 900 m and nearer 35 mph around 300 m, enough to damage a tent on open ground. Pitch low down and in real shelter, or leave it for another night. It should stay dry. Up around 900 m you'd likely be in cloud for part of the night: damp, and hard to find your way if you need to move. The air is damp at every height we checked (300-900 m), so expect heavy condensation. Leave the vents open. A cold night, down to about 2°C around 900 m. A warm 3-season or 3–4 season bag rated to about 0°C comfort, and a warm mat, should do. Allow more if you sleep cold.

Overnight rain0.0 mm Open ground · 600 m25 mph · gusts 42 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 0°C or lower

Moon overnight

Waning crescent moon

Illuminated disc
18%
Moonrise
02:49 next morning GMT
Moonset
Outside this window

Extensive cloud may limit moonlight. Illumination describes the sunlit part of the Moon, not brightness at your pitch.

Overnight window: 4 Nov, 17:00 GMT to 5 Nov, 08:00 GMT. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.

Elevation reference (open ground)

300 m39 · poor
Wind / gust
21 mph / 35 mph
Typical / low
3.7°C / 3.3°C · much of the night
In cloud
0% of modelled night
Condensation
High
600 m19 · very poor
Wind / gust
25 mph / 42 mph
Typical / low
3.7°C / 3.3°C · much of the night
In cloud
0% of modelled night
Condensation
High
900 m9 · very poor
Wind / gust
30 mph / 50 mph
Typical / low
2.1°C / 1.7°C · much of the night
In cloud
40% of modelled night
Condensation
High

Warmth planning: As a broad starting point, consider a warm 3-season or 3–4 season bag with an ISO/EN comfort rating at or below about 0°C. Allow more margin if you sleep cold or expect fatigue, and use an adequate insulated mat. Dampness is possible, so keep the sleep system dry and ensure its insulation remains effective if damp.

Open-hillside reference. A sheltered pitch may be calmer; cols and ridges may be much windier. Tent design and the exact pitch still matter. Read about sleeping-bag comfort ratings, pitching in strong winds or using the wild-camping forecast.

Did this match your night?Share a quick observation to help improve this beta forecast.Give feedback

Approximate height is enough, please do not share an exact wild-camp location.

Daytime · exposed rockClimbing & scramblingBetaPoor conditions for exposed scrambling: gusts of 40–50 mph. Poor20 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Poor conditions for exposed scrambling. The rock should be mostly dry, though drainage lines and shaded holds may still be damp. Gusts of 40–50 mph could throw you off balance on exposed moves and ridges. Cloud on the tops may make route-finding and retreat harder. The rock around the summit is mostly basalt, a dark volcanic rock. It grips well when dry and can be very slippery when wet. It is often blocky and shattered, with loose rubble on ledges. On the usual routes up you may also cross volcanic tuff, which is rough and grippy when dry and usually still grips reasonably when wet. On the usual routes up you may also cross mudstone or slate, which has only fair grip even when dry and is slippery when wet. These are general notes for each rock type, taken from geological maps around the summit, so the rock on your line may differ.

Rock surfaceProbably dryPeak gust40-50 mphRain0.1 mm
Main factorsgusts of 40–50 mphmuch of the route may be in cloud
Representative rock around the summit and along available routes Basalt Bedded Pyroclastic Formation
Origin
Igneous
Broad rock-response group
Volcanic rock
Mapping
BGS Geology 50K · 1:50,000
Summit area
Volcanic rock in 100% of 17 BGS samples within 350 m
Rock-response profile
Low confidence
View the summit BGS record

Basalt is a dark volcanic rock. It grips well when dry and can be very slippery when wet. It is often blocky and shattered, with loose rubble on ledges. These are general notes for each rock type, from geological map samples at and around the summit. The rock on your line can differ, and lichen, vegetation and seepage all change how it feels underfoot.

Rock groups along the sampled routes

These are mapped rock groups, not separate weather forecasts or a ranking of route safety.

Snowdon Horseshoe

volcanic rock

Snowdon Llanberis

volcanic rock, slate or mudstone

Snowdon Miners Track

volcanic rock

Snowdon Pyg Track

volcanic rock

Snowdon Ranger Path

volcanic rock, sandstone or gritstone

Geological detail and BGS records
Mapped variation

10 rock types appear in the mapped samples

Samples around the summit inform the main rock-response profile, with the summit pin shown separately where it differs. Route samples add further context, but this is not a continuous geological survey.

Summit-area sample Basalt Bedded Pyroclastic Formation 870–964 m samples Seen on Peak Snowdon Miners Track, Peak Snowdon Pyg Track

Basalt is a dark volcanic rock. It grips well when dry and can be very slippery when wet. It is often blocky and shattered, with loose rubble on ledges.

BGS record
Summit-area sample Pyroclastic rock Bedded Pyroclastic Formation 449–1,040 m samples Seen on Peak Snowdon Horseshoe, Peak Snowdon Llanberis, Peak Snowdon Miners Track and 2 more

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record
Summit-area sample Rhyolite Unnamed Igneous Intrusion, Ordovician 460–955 m samples Seen on Peak Snowdon Horseshoe, Peak Snowdon Miners Track, Peak Snowdon Pyg Track and 1 more

Rhyolite is a hard, fine-grained volcanic rock. It grips well when dry and gets slippery on smoother faces when wet. It is hard, but often cracked into sharp, blocky pieces, so some holds are loose.

BGS record
Route sample Felsic tuff Lower Rhyolitic Tuff Formation 447–705 m samples Seen on Peak Snowdon Miners Track, Peak Snowdon Ranger Path

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record
Route sample Mudstone and siltstone Cwm Eigiau Formation Around 580 m Seen on Peak Snowdon Llanberis

Mudstone or slate is a soft, fine-grained rock that splits into thin flakes. It has only fair grip even when dry and is slippery when wet. It is often shattered, breaking into loose flakes, scree and poor holds.

BGS record
Route sample Sandstone Llewelyn Volcanic Group Around 483 m Seen on Peak Snowdon Ranger Path

Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away.

BGS record
Route sample Sandstone Cwm Eigiau Formation Around 600 m Seen on Peak Snowdon Ranger Path

Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away.

BGS record
Route sample Siltstone Nant Ffrancon Subgroup Around 462 m Seen on Peak Snowdon Llanberis

Mudstone or slate is a soft, fine-grained rock that splits into thin flakes. It has only fair grip even when dry and is slippery when wet. It is often shattered, breaking into loose flakes, scree and poor holds.

BGS record
Route sample Tuff and sandstone Bedded Pyroclastic Formation Around 687 m Seen on Peak Snowdon Llanberis

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record
Summit-area sample Felsic tuff Upper Rhyolitic Tuff Formation

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record

Generic exposed scrambling terrain; BGS summit-area bedrock samples are included where available, but route grade, exact rock, polish, drainage and escape options remain unresolved. Contains British Geological Survey materials © UKRI 2026. How to use the climbing and scrambling forecast.

Did this match your experience?Tell us about the rock surface and wind to help improve this beta forecast.Give feedback

A broad surface report is enough; you do not need to identify a particular route.

Overnight · Aurora, stars & meteorsAfter darkBetaSome breaks in the cloud, so stars at times. View forecastClose forecast

After dark: aurora and stargazing

Night beginning 2026-11-04. All times are UK local time.

Aurora is unlikely on this night

A noticeable aurora display is unlikely here. Any glow may be faint or camera-only. Activity peaks around Kp 3.0 (on a 0 to 9 scale).

Activity can change at short notice. Check again on the night.

Stargazing

Mixed sky conditions during the best available spell: 4 Nov, 22:00 GMT to 23:00 GMT.

Some breaks in the cloud, so stars at times.

Moon-free dark sky: 4 Nov, 18:40 GMT to 5 Nov, 02:55 GMT.

Sky conditions through the night
Fully dark periods. Conditions can change between forecast hours.
TimeViewing conditions
4 Nov, 18:40 GMT to 19:00 GMTPoor sky conditions

Some forecasts show clear spells, others keep it cloudy; check again nearer the time.

Forecast models disagree.

4 Nov, 19:00 GMT to 20:00 GMTPoor sky conditions

Some forecasts show clear spells, others keep it cloudy; check again nearer the time.

Forecast models disagree.

4 Nov, 20:00 GMT to 21:00 GMTPoor sky conditions

Some forecasts show clear spells, others keep it cloudy; check again nearer the time.

Forecast models disagree.

4 Nov, 21:00 GMT to 22:00 GMTMixed sky conditions

Some forecasts show clear spells, others keep it cloudy; check again nearer the time.

Forecast models disagree.

4 Nov, 22:00 GMT to 23:00 GMTMixed sky conditions

Some breaks in the cloud, so stars at times.

4 Nov, 23:00 GMT to 5 Nov, 00:00 GMTMixed sky conditions

Some breaks in the cloud, so stars at times.

5 Nov, 00:00 GMT to 01:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

5 Nov, 01:00 GMT to 02:00 GMTMixed sky conditions

Mostly cloudy, so little chance of seeing the stars.

5 Nov, 02:00 GMT to 03:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

5 Nov, 03:00 GMT to 04:00 GMTMixed sky conditions

Some forecasts show clear spells, others keep it cloudy; check again nearer the time.

Forecast models disagree.

5 Nov, 04:00 GMT to 05:00 GMTPoor sky conditions

Some forecasts show clear spells, others keep it cloudy; check again nearer the time.

Forecast models disagree.

5 Nov, 05:00 GMT to 05:25 GMTPoor sky conditions

Some forecasts show clear spells, others keep it cloudy; check again nearer the time.

Forecast models disagree.

Moon, darkness and meteor showers

Crescent moon, about 18% illuminated.

Moonrise around 5 Nov, 02:55 GMT.

Full darkness: 4 Nov, 18:40 GMT to 5 Nov, 05:25 GMT.

Moon times assume an open horizon. Hills can hide the Moon sooner. Moon-free does not mean cloud-free.

Southern Taurids are active on this night. Activity may be much lower away from the peak.

Orionids are active on this night. Activity may be much lower away from the peak.

Northern Taurids are active on this night. Activity may be much lower away from the peak.

  • Southern Taurids: peak around 10 October 2026.
  • Orionids: peak around 21 October 2026.
  • Northern Taurids: peak around 12 November 2026.
  • Leonids: peak around 18 November 2026.
  • Geminids: peak around 14 December 2026.
  • Ursids: peak around 22 December 2026.

Dates from the Royal Observatory Greenwich. Activity dates do not guarantee visible meteors. Look across a broad, dark sky, not only north.

Darkness of the surroundings

Estimated darkness rank 814 of 980 assessed peaks (1 is darkest), based on surrounding artificial light in 2021. This is not a measurement of tonight’s sky.

2021 artificial-light baseline, not measured sky brightness or a Bortle class. Changes to lighting, blue-rich LEDs, terrain screening, atmospheric scattering and cloud-reflected light are not resolved. Similar ranks are not meaningfully distinct. Darkness is not a recommendation to climb a summit at night.

VIIRS nighttime lights: Earth Observation Group, Payne Institute for Public Policy, Colorado School of Mines. Reprocessed by OpenGeoHub/OpenLandMap. Cropped and ranked by Mountain Weather.

Sky-weather grades exclude light pollution, terrain and thin haze. They are not mountain safety ratings. Check the mountain and camping forecast separately. Accessible lower viewpoints may be a better choice than summits.

Explore the dedicated aurora forecast, meteor shower forecast or dark-sky and astrophotography forecast.

Recommended kit for this dayWeather-aware packing prompts, plus your core hillwalking kitView kit

For a day hillwalk, not a complete route-specific checklist. Carry navigation and backup you can use, warm and waterproof layers, suitable footwear, food and water, a headtorch, emergency shelter, first aid and a way to call for help. Snow, ice, technical terrain and overnight trips need additional equipment and skills.

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Help the Mountain Decisions Project understand how forecasts influence hill days, including when plans stay the same. Findings will be shared publicly as summaries, not individual responses.

This is about Crib y Ddysgl on Wednesday 4 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.

Open the questions to take part.

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Confidence: Medium
Overall hill weather61Mixed
Summit wind · 08:00-17:0015-35 mph easterly Summit gusts · 08:00-17:0035-45 mph Feels like-10 to -6°C PrecipitationLittle or none Cloud-free summit estimate45% Cloud base through day1,100-1,400 m Freezing levelAbove summit DaylightSunrise 07:20 · Sunset 16:37 · 9.3 hours daylight

The day on the hill

A mixed day on Crib y Ddysgl, with a blustery wind and cloud coming and going on the summit.

Wind

On the summit expect an easterly wind of around 25–35 mph first thing, easing to 15–25 mph by mid-afternoon, with gusts of 35–45 mph at the windiest. Lower down on the open hillside it will be more like 10–20 mph. Gusts like that are strong enough to make walking into it hard work, with buffeting on ridges and edges.

Cloud and visibility

The tops are likely to drift in and out of cloud, with the best chance of a clear summit in the early afternoon. The cloud base could be as low as 600–900 m early in the morning.

Rain and ground

It should stay dry.

Warmth and kit

On the tops it will be around -2 to 2°C, feeling like -10 to -6°C in the wind. The freezing level is above the summits. Take a hat, gloves, a windproof and a spare warm layer.

Daylight

Sunset is around 4:35pm, so allow time to get off the hill before dark, and carry a head torch.

Forecast confidence

Cloud height is hard to pin down, so the summit could be in or out of cloud at short notice. Some of the detail could still change, so have a last look at the forecast in the morning before you set off.

Sunshine context Model-grid estimate, not summit sunshine

The surrounding model grid indicates 1.5 h of sunshine. This is not a forecast of time in sunshine on the summit. Use the cloud and views outlook above for the conditions on this mountain.

Cloud may obscure this summit even while the surrounding model grid indicates sunshine. The low cloud-free summit estimate is a reason to be cautious about expecting views.

Early
Less than 1 hour
Midday
1.3 h
Later
0 h

Overnight forecast: 17:00–08:00 (UK local time), in Wild camping below.

Morning · 08:00–12:00 Mixed Summit winds around 20-35 mph. Gusts around 35-45 mph are possible on exposed ground. Gusts this strong can make walking into it hard work, with buffeting on ridges and edges. Summit cloud becomes more persistent later.
53
Afternoon · 12:00–17:00 Mixed Summit winds around 15-25 mph. Gusts around 25-35 mph are possible on exposed ground. Summit cloud is more persistent early in this period, with better prospects later.
69

Compare an early start with later conditions. The main forecast above covers the day in more detail.

Overnight · 17:00–08:00Wild campingBetaA mixed night to camp, mainly because of the wind: gusts of about 30 mph. 59Mixed · 600 m View detailsHide details
Night beginning Thursday 5 November 2026

Full overnight outlook

A mixed night to camp, mainly because of the wind. Gusts reach about 30 mph on open ground, so peg out well and use the guylines. Look for shelter from the east. It should stay dry. Up around 900 m you'd likely be in cloud for part of the night: damp, and hard to find your way if you need to move. The air is damp up around 900 m, so expect heavy condensation. Leave the vents open. A cold night, down to about 2°C around 900 m. A warm 3-season or 3–4 season bag rated to about 0°C comfort, and a warm mat, should do. Allow more if you sleep cold.

Overnight rain0.0 mm Open ground · 600 m11 mph · gusts 26 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 0°C or lower

Moon overnight

Waning crescent moon

Illuminated disc
11%
Moonrise
04:08 next morning GMT
Moonset
Outside this window

Extensive cloud may limit moonlight. Illumination describes the sunlit part of the Moon, not brightness at your pitch.

Overnight window: 5 Nov, 17:00 GMT to 6 Nov, 08:00 GMT. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.

Elevation reference (open ground)

300 m59 · mixed
Wind / gust
9 mph / 21 mph
Typical / low
3.6°C / 3.4°C · much of the night
In cloud
0% of modelled night
Condensation
Moderate
600 m59 · mixed
Wind / gust
11 mph / 26 mph
Typical / low
3.6°C / 3.4°C · much of the night
In cloud
0% of modelled night
Condensation
Moderate
900 m56 · mixed
Wind / gust
13 mph / 30 mph
Typical / low
1.8°C / 1.6°C · much of the night
In cloud
27% of modelled night
Condensation
High

Warmth planning: As a broad starting point, consider a warm 3-season or 3–4 season bag with an ISO/EN comfort rating at or below about 0°C. Allow more margin if you sleep cold or expect fatigue, and use an adequate insulated mat. Dampness is possible, so keep the sleep system dry and ensure its insulation remains effective if damp.

Open-hillside reference. A sheltered pitch may be calmer; cols and ridges may be much windier. Tent design and the exact pitch still matter. Read about sleeping-bag comfort ratings, pitching in strong winds or using the wild-camping forecast.

Did this match your night?Share a quick observation to help improve this beta forecast.Give feedback

Approximate height is enough, please do not share an exact wild-camp location.

Daytime · exposed rockClimbing & scramblingBetaPoor conditions for exposed scrambling: gusts of 35–45 mph. Poor38 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Poor conditions for exposed scrambling. The rock should be mostly dry, though drainage lines and shaded holds may still be damp. Gusts of 35–45 mph could throw you off balance on exposed moves and ridges. Cloud on the tops may make route-finding and retreat harder. The rock around the summit is mostly basalt, a dark volcanic rock. It grips well when dry and can be very slippery when wet. It is often blocky and shattered, with loose rubble on ledges. On the usual routes up you may also cross volcanic tuff, which is rough and grippy when dry and usually still grips reasonably when wet. On the usual routes up you may also cross mudstone or slate, which has only fair grip even when dry and is slippery when wet. These are general notes for each rock type, taken from geological maps around the summit, so the rock on your line may differ.

Rock surfaceProbably dryPeak gust35-45 mphRain0.0 mm
Main concerngusts of 35–45 mph
Representative rock around the summit and along available routes Basalt Bedded Pyroclastic Formation
Origin
Igneous
Broad rock-response group
Volcanic rock
Mapping
BGS Geology 50K · 1:50,000
Summit area
Volcanic rock in 100% of 17 BGS samples within 350 m
Rock-response profile
Low confidence
View the summit BGS record

Basalt is a dark volcanic rock. It grips well when dry and can be very slippery when wet. It is often blocky and shattered, with loose rubble on ledges. These are general notes for each rock type, from geological map samples at and around the summit. The rock on your line can differ, and lichen, vegetation and seepage all change how it feels underfoot.

Rock groups along the sampled routes

These are mapped rock groups, not separate weather forecasts or a ranking of route safety.

Snowdon Horseshoe

volcanic rock

Snowdon Llanberis

volcanic rock, slate or mudstone

Snowdon Miners Track

volcanic rock

Snowdon Pyg Track

volcanic rock

Snowdon Ranger Path

volcanic rock, sandstone or gritstone

Geological detail and BGS records
Mapped variation

10 rock types appear in the mapped samples

Samples around the summit inform the main rock-response profile, with the summit pin shown separately where it differs. Route samples add further context, but this is not a continuous geological survey.

Summit-area sample Basalt Bedded Pyroclastic Formation 870–964 m samples Seen on Peak Snowdon Miners Track, Peak Snowdon Pyg Track

Basalt is a dark volcanic rock. It grips well when dry and can be very slippery when wet. It is often blocky and shattered, with loose rubble on ledges.

BGS record
Summit-area sample Pyroclastic rock Bedded Pyroclastic Formation 449–1,040 m samples Seen on Peak Snowdon Horseshoe, Peak Snowdon Llanberis, Peak Snowdon Miners Track and 2 more

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record
Summit-area sample Rhyolite Unnamed Igneous Intrusion, Ordovician 460–955 m samples Seen on Peak Snowdon Horseshoe, Peak Snowdon Miners Track, Peak Snowdon Pyg Track and 1 more

Rhyolite is a hard, fine-grained volcanic rock. It grips well when dry and gets slippery on smoother faces when wet. It is hard, but often cracked into sharp, blocky pieces, so some holds are loose.

BGS record
Route sample Felsic tuff Lower Rhyolitic Tuff Formation 447–705 m samples Seen on Peak Snowdon Miners Track, Peak Snowdon Ranger Path

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record
Route sample Mudstone and siltstone Cwm Eigiau Formation Around 580 m Seen on Peak Snowdon Llanberis

Mudstone or slate is a soft, fine-grained rock that splits into thin flakes. It has only fair grip even when dry and is slippery when wet. It is often shattered, breaking into loose flakes, scree and poor holds.

BGS record
Route sample Sandstone Llewelyn Volcanic Group Around 483 m Seen on Peak Snowdon Ranger Path

Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away.

BGS record
Route sample Sandstone Cwm Eigiau Formation Around 600 m Seen on Peak Snowdon Ranger Path

Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away.

BGS record
Route sample Siltstone Nant Ffrancon Subgroup Around 462 m Seen on Peak Snowdon Llanberis

Mudstone or slate is a soft, fine-grained rock that splits into thin flakes. It has only fair grip even when dry and is slippery when wet. It is often shattered, breaking into loose flakes, scree and poor holds.

BGS record
Route sample Tuff and sandstone Bedded Pyroclastic Formation Around 687 m Seen on Peak Snowdon Llanberis

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record
Summit-area sample Felsic tuff Upper Rhyolitic Tuff Formation

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record

Generic exposed scrambling terrain; BGS summit-area bedrock samples are included where available, but route grade, exact rock, polish, drainage and escape options remain unresolved. Contains British Geological Survey materials © UKRI 2026. How to use the climbing and scrambling forecast.

Did this match your experience?Tell us about the rock surface and wind to help improve this beta forecast.Give feedback

A broad surface report is enough; you do not need to identify a particular route.

Overnight · Aurora, stars & meteorsAfter darkBetaMostly cloudy, so little chance of seeing the stars. View forecastClose forecast

After dark: aurora and stargazing

Night beginning 2026-11-05. All times are UK local time.

Aurora is unlikely on this night

A noticeable aurora display is unlikely here. Any glow may be faint or camera-only. Activity peaks around Kp 3.7 (on a 0 to 9 scale). NOAA has a G1 storm watch out for this date, though the timing of the strongest activity can shift.

Activity can change at short notice. Check again on the night.

Stargazing

Poor sky conditions during the best available spell: 6 Nov, 00:00 GMT to 01:00 GMT.

Mostly cloudy, so little chance of seeing the stars.

Moon-free dark sky: 5 Nov, 18:35 GMT to 6 Nov, 04:20 GMT.

Sky conditions through the night
Fully dark periods. Conditions can change between forecast hours.
TimeViewing conditions
5 Nov, 18:35 GMT to 19:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

5 Nov, 19:00 GMT to 20:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

5 Nov, 20:00 GMT to 21:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

5 Nov, 21:00 GMT to 22:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

5 Nov, 22:00 GMT to 23:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

5 Nov, 23:00 GMT to 6 Nov, 00:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

6 Nov, 00:00 GMT to 01:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

6 Nov, 01:00 GMT to 02:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

6 Nov, 02:00 GMT to 03:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

6 Nov, 03:00 GMT to 04:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

6 Nov, 04:00 GMT to 05:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

6 Nov, 05:00 GMT to 05:25 GMTPoor sky conditions

Some forecasts show clear spells, others keep it cloudy; check again nearer the time.

Forecast models disagree.

Moon, darkness and meteor showers

Crescent moon, about 10% illuminated.

Moonrise around 6 Nov, 04:20 GMT.

Full darkness: 5 Nov, 18:35 GMT to 6 Nov, 05:25 GMT.

Moon times assume an open horizon. Hills can hide the Moon sooner. Moon-free does not mean cloud-free.

Southern Taurids are active on this night. Activity may be much lower away from the peak.

Orionids are active on this night. Activity may be much lower away from the peak.

Northern Taurids are active on this night. Activity may be much lower away from the peak.

Leonids are active on this night. Activity may be much lower away from the peak.

  • Southern Taurids: peak around 10 October 2026.
  • Orionids: peak around 21 October 2026.
  • Northern Taurids: peak around 12 November 2026.
  • Leonids: peak around 18 November 2026.
  • Geminids: peak around 14 December 2026.
  • Ursids: peak around 22 December 2026.

Dates from the Royal Observatory Greenwich. Activity dates do not guarantee visible meteors. Look across a broad, dark sky, not only north.

Darkness of the surroundings

Estimated darkness rank 814 of 980 assessed peaks (1 is darkest), based on surrounding artificial light in 2021. This is not a measurement of tonight’s sky.

2021 artificial-light baseline, not measured sky brightness or a Bortle class. Changes to lighting, blue-rich LEDs, terrain screening, atmospheric scattering and cloud-reflected light are not resolved. Similar ranks are not meaningfully distinct. Darkness is not a recommendation to climb a summit at night.

VIIRS nighttime lights: Earth Observation Group, Payne Institute for Public Policy, Colorado School of Mines. Reprocessed by OpenGeoHub/OpenLandMap. Cropped and ranked by Mountain Weather.

Sky-weather grades exclude light pollution, terrain and thin haze. They are not mountain safety ratings. Check the mountain and camping forecast separately. Accessible lower viewpoints may be a better choice than summits.

Explore the dedicated aurora forecast, meteor shower forecast or dark-sky and astrophotography forecast.

Recommended kit for this dayWeather-aware packing prompts, plus your core hillwalking kitView kit

For a day hillwalk, not a complete route-specific checklist. Carry navigation and backup you can use, warm and waterproof layers, suitable footwear, food and water, a headtorch, emergency shelter, first aid and a way to call for help. Snow, ice, technical terrain and overnight trips need additional equipment and skills.

Does the weather shape your plans?Optional hill-user research. One answer helps; further questions are up to you.Take part

Help the Mountain Decisions Project understand how forecasts influence hill days, including when plans stay the same. Findings will be shared publicly as summaries, not individual responses.

This is about Crib y Ddysgl on Thursday 5 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.

Open the questions to take part.

About the research and your privacy · Already been out? Share that experience instead

Confidence: Medium
Overall hill weather72Good
Summit wind · 08:00-17:000-15 mph easterly Summit gusts · 08:00-17:0010-20 mph Feels like-4 to 0°C PrecipitationLittle or none Cloud-free summit estimate35% Cloud base through day600-1,400 m Freezing levelAbove summit DaylightSunrise 07:22 · Sunset 16:36 · 9.2 hours daylight

The day on the hill

A good day on Crib y Ddysgl, though expect cloud coming and going on the summit.

Wind

On the summit expect light winds of up to 15 mph, mainly easterly, with gusts of 10–20 mph at the windiest.

Cloud and visibility

The tops are likely to drift in and out of cloud, with the best chance of a clear summit early in the morning. The cloud base could be as low as 600–900 m mid-morning. In cloud you'll be finding your way without landmarks, so carry navigation you trust and know how to use, with a backup such as a spare battery or a map and compass.

Rain and ground

It should stay dry.

Warmth and kit

On the tops it will be around 0 to 4°C, feeling like -4 to 0°C in the wind. The freezing level is above the summits. Take a hat, gloves, a windproof and a spare warm layer.

Daylight

Sunset is around 4:35pm, so allow time to get off the hill before dark, and carry a head torch.

Forecast confidence

Cloud height is hard to pin down, so the summit could be in or out of cloud at short notice. It's still two days off and could change, so check again nearer the time.

Sunshine context Model-grid estimate, not summit sunshine

The surrounding model grid indicates 0.8 h of sunshine. This is not a forecast of time in sunshine on the summit. Use the cloud and views outlook above for the conditions on this mountain.

Cloud may obscure this summit even while the surrounding model grid indicates sunshine. The low cloud-free summit estimate is a reason to be cautious about expecting views.

Early
Less than 1 hour
Midday
Less than 1 hour
Later
0 h

Overnight forecast: 17:00–08:00 (UK local time), in Wild camping below.

Morning · 08:00–12:00 Good Summit winds around 5-15 mph. Gusts around 10-20 mph are possible on exposed ground.
79
Afternoon · 12:00–17:00 Mixed Summit winds around 0-10 mph. Gusts around 5-15 mph are possible on exposed ground.
65

Compare an early start with later conditions. The main forecast above covers the day in more detail.

Overnight · 17:00–08:00Wild campingBetaA mixed night to camp, mainly because of damp air: gusts of about 10 mph. 59Mixed · 600 m View detailsHide details
Night beginning Friday 6 November 2026

Full overnight outlook

A mixed night to camp, mainly because of damp air. Light winds on open ground, gusting no more than about 10 mph. Dry to pitch, then a little rain overnight, easing by morning, though the tent may still be wet. Up around 900 m you'd likely be in cloud for part of the night: damp, and hard to find your way if you need to move. The air is damp at every height we checked (300-900 m), so expect heavy condensation. Leave the vents open. A cold night, down to about 1°C around 900 m. A warm 3-season or 3–4 season bag rated to about 0°C comfort, and a warm mat, should do. Allow more if you sleep cold.

Overnight rain0.6 mm Open ground · 600 m7 mph · gusts 10 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 0°C or lower

Moon overnight

Waning crescent moon

Illuminated disc
5%
Moonrise
05:27 next morning GMT
Moonset
Outside this window

Cloud may affect views of the Moon. Illumination describes the sunlit part of the Moon, not brightness at your pitch.

Overnight window: 6 Nov, 17:00 GMT to 7 Nov, 08:00 GMT. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.

Elevation reference (open ground)

300 m59 · mixed
Wind / gust
6 mph / 9 mph
Typical / low
3.9°C / 3.6°C · much of the night
In cloud
0% of modelled night
Condensation
High
600 m59 · mixed
Wind / gust
7 mph / 10 mph
Typical / low
3.9°C / 3.6°C · much of the night
In cloud
0% of modelled night
Condensation
High
900 m54 · mixed
Wind / gust
9 mph / 12 mph
Typical / low
2.1°C / 1.4°C · much of the night
In cloud
87% of modelled night
Condensation
High

Warmth planning: As a broad starting point, consider a warm 3-season or 3–4 season bag with an ISO/EN comfort rating at or below about 0°C. Allow more margin if you sleep cold or expect fatigue, and use an adequate insulated mat. Dampness is possible, so keep the sleep system dry and ensure its insulation remains effective if damp.

Open-hillside reference. A sheltered pitch may be calmer; cols and ridges may be much windier. Tent design and the exact pitch still matter. Read about sleeping-bag comfort ratings, pitching in strong winds or using the wild-camping forecast.

Did this match your night?Share a quick observation to help improve this beta forecast.Give feedback

Approximate height is enough, please do not share an exact wild-camp location.

Daytime · exposed rockClimbing & scramblingBetaFair conditions for exposed scrambling. Mixed69 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Fair conditions for exposed scrambling. It should stay mostly dry, but a passing shower could leave the rock damp and slippery. Cloud on the tops may make route-finding and retreat harder. The rock around the summit is mostly basalt, a dark volcanic rock. It grips well when dry and can be very slippery when wet. It is often blocky and shattered, with loose rubble on ledges. On the usual routes up you may also cross volcanic tuff, which is rough and grippy when dry and usually still grips reasonably when wet. On the usual routes up you may also cross mudstone or slate, which has only fair grip even when dry and is slippery when wet. These are general notes for each rock type, taken from geological maps around the summit, so the rock on your line may differ.

Rock surfaceDry initially; rain possiblePeak gust10-20 mphRainPossible · 30%
Main factorsrain possible despite mostly dry conditions being favouredmuch of the route may be in cloud
Representative rock around the summit and along available routes Basalt Bedded Pyroclastic Formation
Origin
Igneous
Broad rock-response group
Volcanic rock
Mapping
BGS Geology 50K · 1:50,000
Summit area
Volcanic rock in 100% of 17 BGS samples within 350 m
Rock-response profile
Low confidence
View the summit BGS record

Basalt is a dark volcanic rock. It grips well when dry and can be very slippery when wet. It is often blocky and shattered, with loose rubble on ledges. These are general notes for each rock type, from geological map samples at and around the summit. The rock on your line can differ, and lichen, vegetation and seepage all change how it feels underfoot.

Rock groups along the sampled routes

These are mapped rock groups, not separate weather forecasts or a ranking of route safety.

Snowdon Horseshoe

volcanic rock

Snowdon Llanberis

volcanic rock, slate or mudstone

Snowdon Miners Track

volcanic rock

Snowdon Pyg Track

volcanic rock

Snowdon Ranger Path

volcanic rock, sandstone or gritstone

Geological detail and BGS records
Mapped variation

10 rock types appear in the mapped samples

Samples around the summit inform the main rock-response profile, with the summit pin shown separately where it differs. Route samples add further context, but this is not a continuous geological survey.

Summit-area sample Basalt Bedded Pyroclastic Formation 870–964 m samples Seen on Peak Snowdon Miners Track, Peak Snowdon Pyg Track

Basalt is a dark volcanic rock. It grips well when dry and can be very slippery when wet. It is often blocky and shattered, with loose rubble on ledges.

BGS record
Summit-area sample Pyroclastic rock Bedded Pyroclastic Formation 449–1,040 m samples Seen on Peak Snowdon Horseshoe, Peak Snowdon Llanberis, Peak Snowdon Miners Track and 2 more

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record
Summit-area sample Rhyolite Unnamed Igneous Intrusion, Ordovician 460–955 m samples Seen on Peak Snowdon Horseshoe, Peak Snowdon Miners Track, Peak Snowdon Pyg Track and 1 more

Rhyolite is a hard, fine-grained volcanic rock. It grips well when dry and gets slippery on smoother faces when wet. It is hard, but often cracked into sharp, blocky pieces, so some holds are loose.

BGS record
Route sample Felsic tuff Lower Rhyolitic Tuff Formation 447–705 m samples Seen on Peak Snowdon Miners Track, Peak Snowdon Ranger Path

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record
Route sample Mudstone and siltstone Cwm Eigiau Formation Around 580 m Seen on Peak Snowdon Llanberis

Mudstone or slate is a soft, fine-grained rock that splits into thin flakes. It has only fair grip even when dry and is slippery when wet. It is often shattered, breaking into loose flakes, scree and poor holds.

BGS record
Route sample Sandstone Llewelyn Volcanic Group Around 483 m Seen on Peak Snowdon Ranger Path

Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away.

BGS record
Route sample Sandstone Cwm Eigiau Formation Around 600 m Seen on Peak Snowdon Ranger Path

Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away.

BGS record
Route sample Siltstone Nant Ffrancon Subgroup Around 462 m Seen on Peak Snowdon Llanberis

Mudstone or slate is a soft, fine-grained rock that splits into thin flakes. It has only fair grip even when dry and is slippery when wet. It is often shattered, breaking into loose flakes, scree and poor holds.

BGS record
Route sample Tuff and sandstone Bedded Pyroclastic Formation Around 687 m Seen on Peak Snowdon Llanberis

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record
Summit-area sample Felsic tuff Upper Rhyolitic Tuff Formation

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record

Generic exposed scrambling terrain; BGS summit-area bedrock samples are included where available, but route grade, exact rock, polish, drainage and escape options remain unresolved. Contains British Geological Survey materials © UKRI 2026. How to use the climbing and scrambling forecast.

Did this match your experience?Tell us about the rock surface and wind to help improve this beta forecast.Give feedback

A broad surface report is enough; you do not need to identify a particular route.

Overnight · Aurora, stars & meteorsAfter darkBetaSome forecasts show clear spells, others keep it cloudy; check again nearer the time. View forecastClose forecast

After dark: aurora and stargazing

Night beginning 2026-11-06. All times are UK local time.

A noticeable aurora display is unlikely; any glow may be faint or camera-only

A noticeable aurora display is unlikely here. Any glow may be faint or camera-only. Activity peaks around Kp 5.0 (on a 0 to 9 scale). NOAA has a G1 storm watch out for this date, though the timing of the strongest activity can shift.

Activity can change at short notice. Check again on the night.

Stargazing

Poor sky conditions during the best available spell: 7 Nov, 04:00 GMT to 05:00 GMT.

Some forecasts show clear spells, others keep it cloudy; check again nearer the time.

Moon-free dark sky: 6 Nov, 18:35 GMT to 7 Nov, 05:25 GMT.

Sky conditions through the night
Fully dark periods. Conditions can change between forecast hours.
TimeViewing conditions
6 Nov, 18:35 GMT to 19:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

6 Nov, 19:00 GMT to 20:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

6 Nov, 20:00 GMT to 21:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

6 Nov, 21:00 GMT to 22:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

6 Nov, 22:00 GMT to 23:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

6 Nov, 23:00 GMT to 7 Nov, 00:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

7 Nov, 00:00 GMT to 01:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

7 Nov, 01:00 GMT to 02:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

7 Nov, 02:00 GMT to 03:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

7 Nov, 03:00 GMT to 04:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

7 Nov, 04:00 GMT to 05:00 GMTPoor sky conditions

Some forecasts show clear spells, others keep it cloudy; check again nearer the time.

Forecast models disagree.

7 Nov, 05:00 GMT to 05:25 GMTPoor sky conditions

Some forecasts show clear spells, others keep it cloudy; check again nearer the time.

Forecast models disagree.

Moon, darkness and meteor showers

Near-new moon, about 5% illuminated.

Moonrise around 7 Nov, 05:40 GMT.

Full darkness: 6 Nov, 18:35 GMT to 7 Nov, 05:25 GMT.

Moon times assume an open horizon. Hills can hide the Moon sooner. Moon-free does not mean cloud-free.

Southern Taurids are active on this night. Activity may be much lower away from the peak.

Orionids are active on this night. Activity may be much lower away from the peak.

Northern Taurids are active on this night. Activity may be much lower away from the peak.

Leonids are active on this night. Activity may be much lower away from the peak.

  • Southern Taurids: peak around 10 October 2026.
  • Orionids: peak around 21 October 2026.
  • Northern Taurids: peak around 12 November 2026.
  • Leonids: peak around 18 November 2026.
  • Geminids: peak around 14 December 2026.
  • Ursids: peak around 22 December 2026.

Dates from the Royal Observatory Greenwich. Activity dates do not guarantee visible meteors. Look across a broad, dark sky, not only north.

Darkness of the surroundings

Estimated darkness rank 814 of 980 assessed peaks (1 is darkest), based on surrounding artificial light in 2021. This is not a measurement of tonight’s sky.

2021 artificial-light baseline, not measured sky brightness or a Bortle class. Changes to lighting, blue-rich LEDs, terrain screening, atmospheric scattering and cloud-reflected light are not resolved. Similar ranks are not meaningfully distinct. Darkness is not a recommendation to climb a summit at night.

VIIRS nighttime lights: Earth Observation Group, Payne Institute for Public Policy, Colorado School of Mines. Reprocessed by OpenGeoHub/OpenLandMap. Cropped and ranked by Mountain Weather.

Sky-weather grades exclude light pollution, terrain and thin haze. They are not mountain safety ratings. Check the mountain and camping forecast separately. Accessible lower viewpoints may be a better choice than summits.

Explore the dedicated aurora forecast, meteor shower forecast or dark-sky and astrophotography forecast.

Recommended kit for this dayWeather-aware packing prompts, plus your core hillwalking kitView kit

For a day hillwalk, not a complete route-specific checklist. Carry navigation and backup you can use, warm and waterproof layers, suitable footwear, food and water, a headtorch, emergency shelter, first aid and a way to call for help. Snow, ice, technical terrain and overnight trips need additional equipment and skills.

Does the weather shape your plans?Optional hill-user research. One answer helps; further questions are up to you.Take part

Help the Mountain Decisions Project understand how forecasts influence hill days, including when plans stay the same. Findings will be shared publicly as summaries, not individual responses.

This is about Crib y Ddysgl on Friday 6 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.

Open the questions to take part.

About the research and your privacy · Already been out? Share that experience instead

Confidence: Medium
Overall hill weather89Excellent
Summit wind · 08:00-17:005-15 mph northwesterly Summit gusts · 08:00-17:005-15 mph Feels like-6 to -2°C PrecipitationLittle or none Cloud-free summit estimate85% Cloud base through day1,000-2,200 m Freezing level900-1,200 m DaylightSunrise 07:24 · Sunset 16:34 · 9.2 hours daylight

The day on the hill

A fine day on Crib y Ddysgl: dry, with light winds and clear tops for most of the day.

Wind

On the summit expect light winds of up to 10 mph, mainly north-westerly, with gusts of 5–15 mph at the windiest. Lower down on the open hillside the wind will be light, under 5 mph.

Cloud and visibility

The tops are likely to drift in and out of cloud, with the best chance of a clear summit mid-morning. A few forecast models bring the cloud base down to around 600–900 m at times. The cloud base sits close to summit height, so the top could go in and out of cloud at short notice. Mist or fog is possible in the valleys early on, clearing by about 10am.

Rain and ground

It should stay dry.

Warmth and kit

On the tops it will be around -2 to 2°C, feeling like -6 to -2°C in the wind. The freezing level is close to summit height. Take a hat, gloves, a windproof and a spare warm layer.

Daylight

Sunset is around 4:35pm, so allow time to get off the hill before dark, and carry a head torch.

Forecast confidence

Cloud height is hard to pin down, so the summit could be in or out of cloud at short notice. It's still three days off and could change, so check again nearer the time.

Sunshine context Model-grid estimate, not summit sunshine

The surrounding model grid indicates 5.2 h of sunshine. This is not a forecast of time in sunshine on the summit. Use the cloud and views outlook above for the conditions on this mountain.

Early
2 h
Midday
1.8 h
Later
0 h

Overnight forecast: 17:00–08:00 (UK local time), in Wild camping below.

Morning · 08:00–12:00 Excellent Summit winds around 5-15 mph. Gusts around 5-15 mph are possible on exposed ground. Summit cloud is more persistent early in this period, with better prospects later.
89
Afternoon · 12:00–17:00 Excellent Summit winds around 5-15 mph. Gusts around 5-15 mph are possible on exposed ground.
89

Compare an early start with later conditions. The main forecast above covers the day in more detail.

Overnight · 17:00–08:00Wild campingBetaA mixed night to camp, mainly because of damp air: gusts of about 15 mph. 54Mixed · 600 m View detailsHide details
Night beginning Saturday 7 November 2026

Full overnight outlook

A mixed night to camp, mainly because of damp air. Light winds on open ground, gusting no more than about 15 mph. Dry to pitch, then a little rain overnight, easing by morning, though the tent may still be wet. Above about 600 m you'd likely be in cloud for part of the night: damp, and hard to find your way if you need to move. The air is damp at every height we checked (300-900 m), so expect heavy condensation. Leave the vents open. A cold night, down to about 2°C around 900 m. A 3-season bag rated to about 2°C comfort, and a warm mat, should do. Allow more if you sleep cold.

Overnight rain0.3 mm Open ground · 600 m8 mph · gusts 12 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 2°C or lower

Moon overnight

Near-new moon

Illuminated disc
2%
Moonrise
06:46 next morning GMT
Moonset
Outside this window

Cloud may affect views of the Moon. Illumination describes the sunlit part of the Moon, not brightness at your pitch.

Overnight window: 7 Nov, 17:00 GMT to 8 Nov, 08:00 GMT. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.

Elevation reference (open ground)

300 m59 · mixed
Wind / gust
7 mph / 10 mph
Typical / low
4.5°C / 4.2°C · much of the night
In cloud
0% of modelled night
Condensation
High
600 m54 · mixed
Wind / gust
8 mph / 12 mph
Typical / low
4.4°C / 4.1°C · much of the night
In cloud
53% of modelled night
Condensation
High
900 m54 · mixed
Wind / gust
9 mph / 13 mph
Typical / low
2.9°C / 1.7°C · much of the night
In cloud
60% of modelled night
Condensation
High

Warmth planning: As a broad starting point, consider a 3-season bag with an ISO/EN comfort rating at or below about 2°C. Allow more margin if you sleep cold or expect fatigue, and use an adequate insulated mat. Dampness is possible, so keep the sleep system dry and ensure its insulation remains effective if damp.

Open-hillside reference. A sheltered pitch may be calmer; cols and ridges may be much windier. Tent design and the exact pitch still matter. Read about sleeping-bag comfort ratings, pitching in strong winds or using the wild-camping forecast.

Did this match your night?Share a quick observation to help improve this beta forecast.Give feedback

Approximate height is enough, please do not share an exact wild-camp location.

Daytime · exposed rockClimbing & scramblingBetaGood conditions for exposed scrambling. Excellent87 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Good conditions for exposed scrambling. It should stay mostly dry, but a passing shower could leave the rock damp and slippery. The rock around the summit is mostly basalt, a dark volcanic rock. It grips well when dry and can be very slippery when wet. It is often blocky and shattered, with loose rubble on ledges. On the usual routes up you may also cross volcanic tuff, which is rough and grippy when dry and usually still grips reasonably when wet. On the usual routes up you may also cross mudstone or slate, which has only fair grip even when dry and is slippery when wet. These are general notes for each rock type, taken from geological maps around the summit, so the rock on your line may differ.

Rock surfaceDry initially; rain possiblePeak gust5-15 mphRainPossible · 28%
Main concernrain possible despite mostly dry conditions being favoured
Representative rock around the summit and along available routes Basalt Bedded Pyroclastic Formation
Origin
Igneous
Broad rock-response group
Volcanic rock
Mapping
BGS Geology 50K · 1:50,000
Summit area
Volcanic rock in 100% of 17 BGS samples within 350 m
Rock-response profile
Low confidence
View the summit BGS record

Basalt is a dark volcanic rock. It grips well when dry and can be very slippery when wet. It is often blocky and shattered, with loose rubble on ledges. These are general notes for each rock type, from geological map samples at and around the summit. The rock on your line can differ, and lichen, vegetation and seepage all change how it feels underfoot.

Rock groups along the sampled routes

These are mapped rock groups, not separate weather forecasts or a ranking of route safety.

Snowdon Horseshoe

volcanic rock

Snowdon Llanberis

volcanic rock, slate or mudstone

Snowdon Miners Track

volcanic rock

Snowdon Pyg Track

volcanic rock

Snowdon Ranger Path

volcanic rock, sandstone or gritstone

Geological detail and BGS records
Mapped variation

10 rock types appear in the mapped samples

Samples around the summit inform the main rock-response profile, with the summit pin shown separately where it differs. Route samples add further context, but this is not a continuous geological survey.

Summit-area sample Basalt Bedded Pyroclastic Formation 870–964 m samples Seen on Peak Snowdon Miners Track, Peak Snowdon Pyg Track

Basalt is a dark volcanic rock. It grips well when dry and can be very slippery when wet. It is often blocky and shattered, with loose rubble on ledges.

BGS record
Summit-area sample Pyroclastic rock Bedded Pyroclastic Formation 449–1,040 m samples Seen on Peak Snowdon Horseshoe, Peak Snowdon Llanberis, Peak Snowdon Miners Track and 2 more

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record
Summit-area sample Rhyolite Unnamed Igneous Intrusion, Ordovician 460–955 m samples Seen on Peak Snowdon Horseshoe, Peak Snowdon Miners Track, Peak Snowdon Pyg Track and 1 more

Rhyolite is a hard, fine-grained volcanic rock. It grips well when dry and gets slippery on smoother faces when wet. It is hard, but often cracked into sharp, blocky pieces, so some holds are loose.

BGS record
Route sample Felsic tuff Lower Rhyolitic Tuff Formation 447–705 m samples Seen on Peak Snowdon Miners Track, Peak Snowdon Ranger Path

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record
Route sample Mudstone and siltstone Cwm Eigiau Formation Around 580 m Seen on Peak Snowdon Llanberis

Mudstone or slate is a soft, fine-grained rock that splits into thin flakes. It has only fair grip even when dry and is slippery when wet. It is often shattered, breaking into loose flakes, scree and poor holds.

BGS record
Route sample Sandstone Llewelyn Volcanic Group Around 483 m Seen on Peak Snowdon Ranger Path

Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away.

BGS record
Route sample Sandstone Cwm Eigiau Formation Around 600 m Seen on Peak Snowdon Ranger Path

Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away.

BGS record
Route sample Siltstone Nant Ffrancon Subgroup Around 462 m Seen on Peak Snowdon Llanberis

Mudstone or slate is a soft, fine-grained rock that splits into thin flakes. It has only fair grip even when dry and is slippery when wet. It is often shattered, breaking into loose flakes, scree and poor holds.

BGS record
Route sample Tuff and sandstone Bedded Pyroclastic Formation Around 687 m Seen on Peak Snowdon Llanberis

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record
Summit-area sample Felsic tuff Upper Rhyolitic Tuff Formation

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record

Generic exposed scrambling terrain; BGS summit-area bedrock samples are included where available, but route grade, exact rock, polish, drainage and escape options remain unresolved. Contains British Geological Survey materials © UKRI 2026. How to use the climbing and scrambling forecast.

Did this match your experience?Tell us about the rock surface and wind to help improve this beta forecast.Give feedback

A broad surface report is enough; you do not need to identify a particular route.

Overnight · Aurora, stars & meteorsAfter darkBetaMostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. View forecastClose forecast

After dark: aurora and stargazing

Night beginning 2026-11-07. All times are UK local time.

Stargazing

Poor sky conditions during the best available spell: 7 Nov, 20:00 GMT to 21:00 GMT.

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

Moon-free dark sky: 7 Nov, 18:35 GMT to 8 Nov, 05:30 GMT.

Sky conditions through the night
Fully dark periods. Conditions can change between forecast hours.
TimeViewing conditions
7 Nov, 18:35 GMT to 19:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

7 Nov, 19:00 GMT to 20:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

7 Nov, 20:00 GMT to 21:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

7 Nov, 21:00 GMT to 22:00 GMTPoor sky conditions

Some breaks in the cloud, so stars at times. Hazy, which dims the fainter stars.

7 Nov, 22:00 GMT to 23:00 GMTPoor sky conditions

Some breaks in the cloud, so stars at times. Hazy, which dims the fainter stars.

7 Nov, 23:00 GMT to 8 Nov, 00:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

8 Nov, 00:00 GMT to 01:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

8 Nov, 01:00 GMT to 02:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

8 Nov, 02:00 GMT to 03:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

8 Nov, 03:00 GMT to 04:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

8 Nov, 04:00 GMT to 05:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

8 Nov, 05:00 GMT to 05:30 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

Moon, darkness and meteor showers

Near-new moon, about 2% illuminated.

Moonrise around 8 Nov, 07:00 GMT.

Full darkness: 7 Nov, 18:35 GMT to 8 Nov, 05:30 GMT.

Moon times assume an open horizon. Hills can hide the Moon sooner. Moon-free does not mean cloud-free.

Southern Taurids are active on this night. Activity may be much lower away from the peak.

Orionids are active on this night. Activity may be much lower away from the peak.

Northern Taurids are active on this night. Activity may be much lower away from the peak.

Leonids are active on this night. Activity may be much lower away from the peak.

  • Southern Taurids: peak around 10 October 2026.
  • Orionids: peak around 21 October 2026.
  • Northern Taurids: peak around 12 November 2026.
  • Leonids: peak around 18 November 2026.
  • Geminids: peak around 14 December 2026.
  • Ursids: peak around 22 December 2026.

Dates from the Royal Observatory Greenwich. Activity dates do not guarantee visible meteors. Look across a broad, dark sky, not only north.

Darkness of the surroundings

Estimated darkness rank 814 of 980 assessed peaks (1 is darkest), based on surrounding artificial light in 2021. This is not a measurement of tonight’s sky.

2021 artificial-light baseline, not measured sky brightness or a Bortle class. Changes to lighting, blue-rich LEDs, terrain screening, atmospheric scattering and cloud-reflected light are not resolved. Similar ranks are not meaningfully distinct. Darkness is not a recommendation to climb a summit at night.

VIIRS nighttime lights: Earth Observation Group, Payne Institute for Public Policy, Colorado School of Mines. Reprocessed by OpenGeoHub/OpenLandMap. Cropped and ranked by Mountain Weather.

Sky-weather grades exclude light pollution, terrain and thin haze. They are not mountain safety ratings. Check the mountain and camping forecast separately. Accessible lower viewpoints may be a better choice than summits.

Explore the dedicated aurora forecast, meteor shower forecast or dark-sky and astrophotography forecast.

Recommended kit for this dayWeather-aware packing prompts, plus your core hillwalking kitView kit

For a day hillwalk, not a complete route-specific checklist. Carry navigation and backup you can use, warm and waterproof layers, suitable footwear, food and water, a headtorch, emergency shelter, first aid and a way to call for help. Snow, ice, technical terrain and overnight trips need additional equipment and skills.

Does the weather shape your plans?Optional hill-user research. One answer helps; further questions are up to you.Take part

Help the Mountain Decisions Project understand how forecasts influence hill days, including when plans stay the same. Findings will be shared publicly as summaries, not individual responses.

This is about Crib y Ddysgl on Saturday 7 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.

Open the questions to take part.

About the research and your privacy · Already been out? Share that experience instead

Confidence: Medium
Overall hill weather90Excellent
Summit wind · 08:00-17:005-15 mph westerly Summit gusts · 08:00-17:0010-20 mph Feels like-6 to -2°C PrecipitationLittle or none Cloud-free summit estimate75% Cloud base through day500-800 m Freezing levelAbove summit DaylightSunrise 07:26 · Sunset 16:32 · 9.1 hours daylight

The day on the hill

A fine day on Crib y Ddysgl: dry, with light winds and clear tops for most of the day.

Wind

On the summit expect light winds of up to 15 mph, mainly westerly, with gusts of 10–20 mph at the windiest.

Cloud and visibility

Any early cloud on the tops should clear soon after dawn. The cloud base could be as low as 500–800 m early in the morning. Mist or fog is possible in the valleys early on, clearing by about 10am. Good spells of sunshine are likely.

Rain and ground

It should stay dry.

Warmth and kit

On the tops it will be around -2 to 2°C, feeling like -6 to -2°C in the wind. The freezing level is close to summit height. Take a hat, gloves, a windproof and a spare warm layer.

Daylight

Sunset is around 4:30pm, so allow time to get off the hill before dark, and carry a head torch.

Forecast confidence

Cloud height is hard to pin down, so the summit could be in or out of cloud at short notice. It's still four days off and could change, so check again nearer the time.

Sunshine context Model-grid estimate, not summit sunshine

The surrounding model grid indicates 8 h of sunshine. This is not a forecast of time in sunshine on the summit. Use the cloud and views outlook above for the conditions on this mountain.

Early
2 h
Midday
4 h
Later
0 h

Overnight forecast: 17:00–08:00 (UK local time), in Wild camping below.

Morning · 08:00–12:00 Good Summit winds around 5-15 mph. Gusts around 10-20 mph are possible on exposed ground. Summit cloud is more persistent early in this period, with better prospects later.
81
Afternoon · 12:00–17:00 Excellent Summit winds around 5-15 mph. Gusts around 10-20 mph are possible on exposed ground.
99

Compare an early start with later conditions. The main forecast above covers the day in more detail.

Overnight · 17:00–08:00Wild campingBetaA very good night for a wild camp: dry, with light winds. 88Excellent · 600 m View detailsHide details
Night beginning Sunday 8 November 2026

Full overnight outlook

A very good night for a wild camp. Light winds on open ground, gusting no more than about 10 mph. It should stay dry. Overnight lows of about 4°C at 900 m. A 3-season bag rated to about 2°C comfort, and a warm mat, should do. Allow more if you sleep cold. It's a few nights off, so check again nearer the time.

Overnight rain0.0 mm Open ground · 600 m3 mph · gusts 8 mph Morning pack-upNo wet signal Sleeping-bag warmthISO comfort rating about 2°C or lower

Elevation reference (open ground)

300 m88 · very good
Wind / gust
2 mph / 7 mph
Typical / low
5.8°C / 5.5°C · much of the night
In cloud
0% of modelled night
Condensation
Low
600 m88 · very good
Wind / gust
3 mph / 8 mph
Typical / low
5.6°C / 5.4°C · much of the night
In cloud
0% of modelled night
Condensation
Low
900 m59 · mixed
Wind / gust
3 mph / 10 mph
Typical / low
4.1°C / 3.5°C · much of the night
In cloud
0% of modelled night
Condensation
Low

Warmth planning: As a broad starting point, consider a 3-season bag with an ISO/EN comfort rating at or below about 2°C. Allow more margin if you sleep cold or expect fatigue, and use an adequate insulated mat. Dampness is possible, so keep the sleep system dry and ensure its insulation remains effective if damp.

Open-hillside reference. A sheltered pitch may be calmer; cols and ridges may be much windier. Tent design and the exact pitch still matter. Read about sleeping-bag comfort ratings, pitching in strong winds or using the wild-camping forecast.

Did this match your night?Share a quick observation to help improve this beta forecast.Give feedback

Approximate height is enough, please do not share an exact wild-camp location.

Daytime · exposed rockClimbing & scramblingBetaGood conditions for exposed scrambling. Excellent85 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Good conditions for exposed scrambling. The rock should be mostly dry, though drainage lines and shaded holds may still be damp. The rock around the summit is mostly basalt, a dark volcanic rock. It grips well when dry and can be very slippery when wet. It is often blocky and shattered, with loose rubble on ledges. On the usual routes up you may also cross volcanic tuff, which is rough and grippy when dry and usually still grips reasonably when wet. On the usual routes up you may also cross mudstone or slate, which has only fair grip even when dry and is slippery when wet. These are general notes for each rock type, taken from geological maps around the summit, so the rock on your line may differ.

Rock surfaceProbably dryPeak gust10-20 mphRain0.0 mm
Representative rock around the summit and along available routes Basalt Bedded Pyroclastic Formation
Origin
Igneous
Broad rock-response group
Volcanic rock
Mapping
BGS Geology 50K · 1:50,000
Summit area
Volcanic rock in 100% of 17 BGS samples within 350 m
Rock-response profile
Low confidence
View the summit BGS record

Basalt is a dark volcanic rock. It grips well when dry and can be very slippery when wet. It is often blocky and shattered, with loose rubble on ledges. These are general notes for each rock type, from geological map samples at and around the summit. The rock on your line can differ, and lichen, vegetation and seepage all change how it feels underfoot.

Rock groups along the sampled routes

These are mapped rock groups, not separate weather forecasts or a ranking of route safety.

Snowdon Horseshoe

volcanic rock

Snowdon Llanberis

volcanic rock, slate or mudstone

Snowdon Miners Track

volcanic rock

Snowdon Pyg Track

volcanic rock

Snowdon Ranger Path

volcanic rock, sandstone or gritstone

Geological detail and BGS records
Mapped variation

10 rock types appear in the mapped samples

Samples around the summit inform the main rock-response profile, with the summit pin shown separately where it differs. Route samples add further context, but this is not a continuous geological survey.

Summit-area sample Basalt Bedded Pyroclastic Formation 870–964 m samples Seen on Peak Snowdon Miners Track, Peak Snowdon Pyg Track

Basalt is a dark volcanic rock. It grips well when dry and can be very slippery when wet. It is often blocky and shattered, with loose rubble on ledges.

BGS record
Summit-area sample Pyroclastic rock Bedded Pyroclastic Formation 449–1,040 m samples Seen on Peak Snowdon Horseshoe, Peak Snowdon Llanberis, Peak Snowdon Miners Track and 2 more

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record
Summit-area sample Rhyolite Unnamed Igneous Intrusion, Ordovician 460–955 m samples Seen on Peak Snowdon Horseshoe, Peak Snowdon Miners Track, Peak Snowdon Pyg Track and 1 more

Rhyolite is a hard, fine-grained volcanic rock. It grips well when dry and gets slippery on smoother faces when wet. It is hard, but often cracked into sharp, blocky pieces, so some holds are loose.

BGS record
Route sample Felsic tuff Lower Rhyolitic Tuff Formation 447–705 m samples Seen on Peak Snowdon Miners Track, Peak Snowdon Ranger Path

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record
Route sample Mudstone and siltstone Cwm Eigiau Formation Around 580 m Seen on Peak Snowdon Llanberis

Mudstone or slate is a soft, fine-grained rock that splits into thin flakes. It has only fair grip even when dry and is slippery when wet. It is often shattered, breaking into loose flakes, scree and poor holds.

BGS record
Route sample Sandstone Llewelyn Volcanic Group Around 483 m Seen on Peak Snowdon Ranger Path

Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away.

BGS record
Route sample Sandstone Cwm Eigiau Formation Around 600 m Seen on Peak Snowdon Ranger Path

Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away.

BGS record
Route sample Siltstone Nant Ffrancon Subgroup Around 462 m Seen on Peak Snowdon Llanberis

Mudstone or slate is a soft, fine-grained rock that splits into thin flakes. It has only fair grip even when dry and is slippery when wet. It is often shattered, breaking into loose flakes, scree and poor holds.

BGS record
Route sample Tuff and sandstone Bedded Pyroclastic Formation Around 687 m Seen on Peak Snowdon Llanberis

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record
Summit-area sample Felsic tuff Upper Rhyolitic Tuff Formation

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record

Generic exposed scrambling terrain; BGS summit-area bedrock samples are included where available, but route grade, exact rock, polish, drainage and escape options remain unresolved. Contains British Geological Survey materials © UKRI 2026. How to use the climbing and scrambling forecast.

Did this match your experience?Tell us about the rock surface and wind to help improve this beta forecast.Give feedback

A broad surface report is enough; you do not need to identify a particular route.

Overnight · Aurora, stars & meteorsAfter darkBetaMostly clear. Hazy, which dims the fainter stars. View forecastClose forecast

After dark: aurora and stargazing

Night beginning 2026-11-08. All times are UK local time.

Aurora outlook

Nothing notable expected.

A broad activity outlook, not a forecast of a visible display. Cloud and activity can change before the night.

Stargazing

Poor sky conditions during the best available spell: 8 Nov, 19:00 GMT to 20:00 GMT.

Mostly clear. Hazy, which dims the fainter stars.

Moon-free dark sky: 8 Nov, 18:30 GMT to 9 Nov, 05:30 GMT.

Sky conditions through the night
Fully dark periods. Conditions can change between forecast hours.
TimeViewing conditions
8 Nov, 18:30 GMT to 19:00 GMTPoor sky conditions

Mostly clear. Hazy, which dims the fainter stars.

8 Nov, 19:00 GMT to 20:00 GMTPoor sky conditions

Mostly clear. Hazy, which dims the fainter stars.

8 Nov, 20:00 GMT to 21:00 GMTPoor sky conditions

Mostly clear. Hazy, which dims the fainter stars.

8 Nov, 21:00 GMT to 22:00 GMTPoor sky conditions

Mostly clear. Hazy, which dims the fainter stars.

8 Nov, 22:00 GMT to 23:00 GMTPoor sky conditions

Some breaks in the cloud, so stars at times. Hazy, which dims the fainter stars.

8 Nov, 23:00 GMT to 9 Nov, 00:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

9 Nov, 00:00 GMT to 01:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

9 Nov, 01:00 GMT to 02:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

9 Nov, 02:00 GMT to 03:00 GMTPoor sky conditions

Some breaks in the cloud, so stars at times. Hazy, which dims the fainter stars.

9 Nov, 03:00 GMT to 04:00 GMTPoor sky conditions

Mostly clear. Hazy, which dims the fainter stars.

9 Nov, 04:00 GMT to 05:00 GMTPoor sky conditions

Some breaks in the cloud, so stars at times. Hazy, which dims the fainter stars.

9 Nov, 05:00 GMT to 05:30 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

Moon, darkness and meteor showers

Near-new moon, about 0% illuminated.

Full darkness: 8 Nov, 18:30 GMT to 9 Nov, 05:30 GMT.

Moon times assume an open horizon. Hills can hide the Moon sooner. Moon-free does not mean cloud-free.

Southern Taurids are active on this night. Activity may be much lower away from the peak.

Northern Taurids are active on this night. Activity may be much lower away from the peak.

Leonids are active on this night. Activity may be much lower away from the peak.

  • Southern Taurids: peak around 10 October 2026.
  • Orionids: peak around 21 October 2026.
  • Northern Taurids: peak around 12 November 2026.
  • Leonids: peak around 18 November 2026.
  • Geminids: peak around 14 December 2026.
  • Ursids: peak around 22 December 2026.

Dates from the Royal Observatory Greenwich. Activity dates do not guarantee visible meteors. Look across a broad, dark sky, not only north.

Darkness of the surroundings

Estimated darkness rank 814 of 980 assessed peaks (1 is darkest), based on surrounding artificial light in 2021. This is not a measurement of tonight’s sky.

2021 artificial-light baseline, not measured sky brightness or a Bortle class. Changes to lighting, blue-rich LEDs, terrain screening, atmospheric scattering and cloud-reflected light are not resolved. Similar ranks are not meaningfully distinct. Darkness is not a recommendation to climb a summit at night.

VIIRS nighttime lights: Earth Observation Group, Payne Institute for Public Policy, Colorado School of Mines. Reprocessed by OpenGeoHub/OpenLandMap. Cropped and ranked by Mountain Weather.

Sky-weather grades exclude light pollution, terrain and thin haze. They are not mountain safety ratings. Check the mountain and camping forecast separately. Accessible lower viewpoints may be a better choice than summits.

Explore the dedicated aurora forecast, meteor shower forecast or dark-sky and astrophotography forecast.

Recommended kit for this dayWeather-aware packing prompts, plus your core hillwalking kitView kit

For a day hillwalk, not a complete route-specific checklist. Carry navigation and backup you can use, warm and waterproof layers, suitable footwear, food and water, a headtorch, emergency shelter, first aid and a way to call for help. Snow, ice, technical terrain and overnight trips need additional equipment and skills.

Does the weather shape your plans?Optional hill-user research. One answer helps; further questions are up to you.Take part

Help the Mountain Decisions Project understand how forecasts influence hill days, including when plans stay the same. Findings will be shared publicly as summaries, not individual responses.

This is about Crib y Ddysgl on Sunday 8 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.

Open the questions to take part.

About the research and your privacy · Already been out? Share that experience instead

Confidence: Medium
Overall hill weather100Excellent
Summit wind · 08:00-17:005-15 mph southeasterly Summit gusts · 08:00-17:005-15 mph Feels like-8 to -4°C PrecipitationLittle or none Cloud-free summit estimate90% Freezing level900-1,200 m DaylightSunrise 07:28 · Sunset 16:30 · 9.1 hours daylight

The day on the hill

A fine day on Crib y Ddysgl: dry, with light winds and clear tops for most of the day.

Wind

On the summit expect light winds of up to 10 mph, mainly south-easterly, with gusts of 5–15 mph at the windiest. Lower down on the open hillside the wind will be light, under 5 mph.

Cloud and visibility

The tops are likely to stay mostly clear of cloud, though brief patches cannot be ruled out.

Rain and ground

It should stay dry.

Warmth and kit

On the tops it will be around -4 to 0°C, feeling like -8 to -4°C in the wind. It turns milder through the day. The freezing level is close to summit height. Take a hat, gloves, a windproof and a spare warm layer.

Daylight

Sunset is around 4:30pm, so allow time to get off the hill before dark, and carry a head torch.

Forecast confidence

Cloud heights are particularly hard to pin down today. It's still five days off and could change, so check again nearer the time.

Sunshine context Model-grid estimate, not summit sunshine

The surrounding model grid indicates 8 h of sunshine. This is not a forecast of time in sunshine on the summit. Use the cloud and views outlook above for the conditions on this mountain.

Early
2 h
Midday
4 h
Later
0 h

Overnight forecast: 17:00–08:00 (UK local time), in Wild camping below.

Morning · 08:00–12:00 Excellent Summit winds around 5-15 mph. Gusts around 5-15 mph are possible on exposed ground.
100
Afternoon · 12:00–17:00 Excellent Summit winds around 5-15 mph. Gusts around 5-15 mph are possible on exposed ground.
100

Compare an early start with later conditions. The main forecast above covers the day in more detail.

Overnight · 17:00–08:00Wild campingBetaA mixed night to camp, mainly because of the wind: gusts of about 30 mph. 59Mixed · 600 m View detailsHide details
Night beginning Monday 9 November 2026

Full overnight outlook

A mixed night to camp, mainly because of the wind. Gusts reach about 30 mph on open ground, so peg out well and use the guylines. Look for shelter from the east. Dry to pitch, then some light rain overnight and into the morning, so expect to pack a wet tent. Above about 600 m you'd likely be in cloud for part of the night: damp, and hard to find your way if you need to move. Overnight lows of about 4°C at 600 m. A warm 3-season or 3–4 season bag rated to about 0°C comfort, and a warm mat, should do. Allow more if you sleep cold.

Overnight rain2.8 mm Open ground · 600 m11 mph · gusts 25 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 0°C or lower

Elevation reference (open ground)

300 m59 · mixed
Wind / gust
9 mph / 21 mph
Typical / low
3.9°C / 3.6°C · much of the night
In cloud
0% of modelled night
Condensation
High
600 m59 · mixed
Wind / gust
11 mph / 25 mph
Typical / low
3.9°C / 3.5°C · much of the night
In cloud
47% of modelled night
Condensation
High
900 m59 · mixed
Wind / gust
14 mph / 30 mph
Typical / low
6.2°C / 3.7°C · several hours
In cloud
47% of modelled night
Condensation
Moderate

Warmth planning: As a broad starting point, consider a warm 3-season or 3–4 season bag with an ISO/EN comfort rating at or below about 0°C. Allow more margin if you sleep cold or expect fatigue, and use an adequate insulated mat. Dampness is possible, so keep the sleep system dry and ensure its insulation remains effective if damp.

Open-hillside reference. A sheltered pitch may be calmer; cols and ridges may be much windier. Tent design and the exact pitch still matter. Read about sleeping-bag comfort ratings, pitching in strong winds or using the wild-camping forecast.

Did this match your night?Share a quick observation to help improve this beta forecast.Give feedback

Approximate height is enough, please do not share an exact wild-camp location.

Daytime · exposed rockClimbing & scramblingBetaGood conditions for exposed scrambling. Excellent87 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Good conditions for exposed scrambling. The rock should be mostly dry, though drainage lines and shaded holds may still be damp. The rock around the summit is mostly basalt, a dark volcanic rock. It grips well when dry and can be very slippery when wet. It is often blocky and shattered, with loose rubble on ledges. On the usual routes up you may also cross volcanic tuff, which is rough and grippy when dry and usually still grips reasonably when wet. On the usual routes up you may also cross mudstone or slate, which has only fair grip even when dry and is slippery when wet. These are general notes for each rock type, taken from geological maps around the summit, so the rock on your line may differ.

Rock surfaceProbably dryPeak gust5-15 mphRain0.0 mm
Representative rock around the summit and along available routes Basalt Bedded Pyroclastic Formation
Origin
Igneous
Broad rock-response group
Volcanic rock
Mapping
BGS Geology 50K · 1:50,000
Summit area
Volcanic rock in 100% of 17 BGS samples within 350 m
Rock-response profile
Low confidence
View the summit BGS record

Basalt is a dark volcanic rock. It grips well when dry and can be very slippery when wet. It is often blocky and shattered, with loose rubble on ledges. These are general notes for each rock type, from geological map samples at and around the summit. The rock on your line can differ, and lichen, vegetation and seepage all change how it feels underfoot.

Rock groups along the sampled routes

These are mapped rock groups, not separate weather forecasts or a ranking of route safety.

Snowdon Horseshoe

volcanic rock

Snowdon Llanberis

volcanic rock, slate or mudstone

Snowdon Miners Track

volcanic rock

Snowdon Pyg Track

volcanic rock

Snowdon Ranger Path

volcanic rock, sandstone or gritstone

Geological detail and BGS records
Mapped variation

10 rock types appear in the mapped samples

Samples around the summit inform the main rock-response profile, with the summit pin shown separately where it differs. Route samples add further context, but this is not a continuous geological survey.

Summit-area sample Basalt Bedded Pyroclastic Formation 870–964 m samples Seen on Peak Snowdon Miners Track, Peak Snowdon Pyg Track

Basalt is a dark volcanic rock. It grips well when dry and can be very slippery when wet. It is often blocky and shattered, with loose rubble on ledges.

BGS record
Summit-area sample Pyroclastic rock Bedded Pyroclastic Formation 449–1,040 m samples Seen on Peak Snowdon Horseshoe, Peak Snowdon Llanberis, Peak Snowdon Miners Track and 2 more

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record
Summit-area sample Rhyolite Unnamed Igneous Intrusion, Ordovician 460–955 m samples Seen on Peak Snowdon Horseshoe, Peak Snowdon Miners Track, Peak Snowdon Pyg Track and 1 more

Rhyolite is a hard, fine-grained volcanic rock. It grips well when dry and gets slippery on smoother faces when wet. It is hard, but often cracked into sharp, blocky pieces, so some holds are loose.

BGS record
Route sample Felsic tuff Lower Rhyolitic Tuff Formation 447–705 m samples Seen on Peak Snowdon Miners Track, Peak Snowdon Ranger Path

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record
Route sample Mudstone and siltstone Cwm Eigiau Formation Around 580 m Seen on Peak Snowdon Llanberis

Mudstone or slate is a soft, fine-grained rock that splits into thin flakes. It has only fair grip even when dry and is slippery when wet. It is often shattered, breaking into loose flakes, scree and poor holds.

BGS record
Route sample Sandstone Llewelyn Volcanic Group Around 483 m Seen on Peak Snowdon Ranger Path

Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away.

BGS record
Route sample Sandstone Cwm Eigiau Formation Around 600 m Seen on Peak Snowdon Ranger Path

Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away.

BGS record
Route sample Siltstone Nant Ffrancon Subgroup Around 462 m Seen on Peak Snowdon Llanberis

Mudstone or slate is a soft, fine-grained rock that splits into thin flakes. It has only fair grip even when dry and is slippery when wet. It is often shattered, breaking into loose flakes, scree and poor holds.

BGS record
Route sample Tuff and sandstone Bedded Pyroclastic Formation Around 687 m Seen on Peak Snowdon Llanberis

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record
Summit-area sample Felsic tuff Upper Rhyolitic Tuff Formation

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record

Generic exposed scrambling terrain; BGS summit-area bedrock samples are included where available, but route grade, exact rock, polish, drainage and escape options remain unresolved. Contains British Geological Survey materials © UKRI 2026. How to use the climbing and scrambling forecast.

Did this match your experience?Tell us about the rock surface and wind to help improve this beta forecast.Give feedback

A broad surface report is enough; you do not need to identify a particular route.

Overnight · Aurora, stars & meteorsAfter darkBetaMostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. View forecastClose forecast

After dark: aurora and stargazing

Night beginning 2026-11-09. All times are UK local time.

Aurora outlook

Nothing notable expected.

A broad activity outlook, not a forecast of a visible display. Cloud and activity can change before the night.

Stargazing

Poor sky conditions during the best available spell: 9 Nov, 19:00 GMT to 20:00 GMT.

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

Moon-free dark sky: 9 Nov, 18:30 GMT to 10 Nov, 05:30 GMT.

Sky conditions through the night
Fully dark periods. Conditions can change between forecast hours.
TimeViewing conditions
9 Nov, 18:30 GMT to 19:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

9 Nov, 19:00 GMT to 20:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

9 Nov, 20:00 GMT to 21:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

9 Nov, 21:00 GMT to 22:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

9 Nov, 22:00 GMT to 23:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

9 Nov, 23:00 GMT to 10 Nov, 00:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

10 Nov, 00:00 GMT to 01:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars.

10 Nov, 01:00 GMT to 02:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars.

10 Nov, 02:00 GMT to 03:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars.

10 Nov, 03:00 GMT to 04:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars.

10 Nov, 04:00 GMT to 05:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars.

10 Nov, 05:00 GMT to 05:30 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars.

Moon, darkness and meteor showers

Near-new moon, about 1% illuminated.

Full darkness: 9 Nov, 18:30 GMT to 10 Nov, 05:30 GMT.

Moon times assume an open horizon. Hills can hide the Moon sooner. Moon-free does not mean cloud-free.

Southern Taurids are active on this night. Activity may be much lower away from the peak.

Northern Taurids are active on this night. Activity may be much lower away from the peak.

Leonids are active on this night. Activity may be much lower away from the peak.

  • Southern Taurids: peak around 10 October 2026.
  • Orionids: peak around 21 October 2026.
  • Northern Taurids: peak around 12 November 2026.
  • Leonids: peak around 18 November 2026.
  • Geminids: peak around 14 December 2026.
  • Ursids: peak around 22 December 2026.

Dates from the Royal Observatory Greenwich. Activity dates do not guarantee visible meteors. Look across a broad, dark sky, not only north.

Darkness of the surroundings

Estimated darkness rank 814 of 980 assessed peaks (1 is darkest), based on surrounding artificial light in 2021. This is not a measurement of tonight’s sky.

2021 artificial-light baseline, not measured sky brightness or a Bortle class. Changes to lighting, blue-rich LEDs, terrain screening, atmospheric scattering and cloud-reflected light are not resolved. Similar ranks are not meaningfully distinct. Darkness is not a recommendation to climb a summit at night.

VIIRS nighttime lights: Earth Observation Group, Payne Institute for Public Policy, Colorado School of Mines. Reprocessed by OpenGeoHub/OpenLandMap. Cropped and ranked by Mountain Weather.

Sky-weather grades exclude light pollution, terrain and thin haze. They are not mountain safety ratings. Check the mountain and camping forecast separately. Accessible lower viewpoints may be a better choice than summits.

Explore the dedicated aurora forecast, meteor shower forecast or dark-sky and astrophotography forecast.

Recommended kit for this dayWeather-aware packing prompts, plus your core hillwalking kitView kit

For a day hillwalk, not a complete route-specific checklist. Carry navigation and backup you can use, warm and waterproof layers, suitable footwear, food and water, a headtorch, emergency shelter, first aid and a way to call for help. Snow, ice, technical terrain and overnight trips need additional equipment and skills.

Does the weather shape your plans?Optional hill-user research. One answer helps; further questions are up to you.Take part

Help the Mountain Decisions Project understand how forecasts influence hill days, including when plans stay the same. Findings will be shared publicly as summaries, not individual responses.

This is about Crib y Ddysgl on Monday 9 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.

Open the questions to take part.

About the research and your privacy · Already been out? Share that experience instead

Confidence: Unavailable
Overall hill weather38Poor
Summit wind · 08:00-17:0015-30 mph easterly Summit gusts · 08:00-17:0025-35 mph Feels like-8 to -4°C PrecipitationAround 2-5 mm Cloud-free summit estimate35% Cloud base through day600-900 m Freezing levelAbove summit DaylightSunrise 07:30 · Sunset 16:29 · 9.0 hours daylight

The day on the hill

A poor day on the tops of Crib y Ddysgl, with drizzle for much of the day and cloud coming and going on the summit.

Wind

On the summit expect an easterly wind of 15–30 mph for most of the day, with gusts of 25–35 mph at the windiest. Lower down on the open hillside it will be more like 5–15 mph. Gusts like that will be noticeable on ridges and open tops, and you will chill quickly when you stop.

Cloud and visibility

Expect the summit to be in cloud for most of the day. The cloud base could be as low as 500–800 m mid-afternoon. In cloud you'll be finding your way without landmarks, so carry navigation you trust and know how to use, with a backup such as a spare battery or a map and compass. Visibility may drop briefly in showers.

Rain and ground

Drizzle for much of the day, turning lighter later. Expect 2–5 mm in total. Some forecast models keep it drier in the morning.

Warmth and kit

On the tops it will be around 0 to 4°C, feeling like -8 to -4°C in the wind. The freezing level is above the summits. Take a hat, gloves, a windproof and a spare warm layer. Pack waterproofs too, and keep a warm layer dry in your pack.

Daylight

A short day, with only about 9 hours of daylight. Sunset is around 4:30pm, so allow time to get off the hill before dark, and carry a head torch.

Forecast confidence

It's still six days off and could change, so check again nearer the time.

Sunshine context Model-grid estimate, not summit sunshine

The surrounding model grid indicates 0 h of sunshine. This is not a forecast of time in sunshine on the summit. Use the cloud and views outlook above for the conditions on this mountain.

Early
0 h
Midday
0 h
Later
0 h

Overnight forecast: 17:00–08:00 (UK local time), in Wild camping below.

Morning · 08:00–12:00 Poor Summit winds around 15-25 mph. Gusts around 25-35 mph are possible on exposed ground. Rain is forecast during this period. Some forecast models bring rain during the morning, while others keep it mostly dry.
37
Afternoon · 12:00–17:00 Poor Rain eases compared with the morning. Summit winds around 20-30 mph. Gusts around 25-35 mph are possible on exposed ground. Rain is forecast during this period.
40

Compare an early start with later conditions. The main forecast above covers the day in more detail.

Overnight · 17:00–08:00Wild campingBetaA mixed night to camp, mainly because of the wind: gusts of about 30 mph. 54Mixed · 600 m View detailsHide details
Night beginning Tuesday 10 November 2026

Full overnight outlook

A mixed night to camp, mainly because of the wind. Gusts reach about 30 mph on open ground, so peg out well and use the guylines. Look for shelter from the east. It should stay dry. Above about 600 m you'd likely be in cloud for part of the night: damp, and hard to find your way if you need to move. The air is damp at every height we checked (300-900 m), so expect heavy condensation. Leave the vents open. A cold night, down to about 2°C around 900 m. A warm 3-season or 3–4 season bag rated to about 0°C comfort, and a warm mat, should do. Allow more if you sleep cold.

Overnight rain0.1 mm Open ground · 600 m16 mph · gusts 27 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 0°C or lower

Elevation reference (open ground)

300 m59 · mixed
Wind / gust
14 mph / 23 mph
Typical / low
4.0°C / 3.8°C · much of the night
In cloud
0% of modelled night
Condensation
High
600 m54 · mixed
Wind / gust
16 mph / 27 mph
Typical / low
3.8°C / 3.5°C · much of the night
In cloud
53% of modelled night
Condensation
High
900 m52 · mixed
Wind / gust
19 mph / 32 mph
Typical / low
2.1°C / 1.8°C · much of the night
In cloud
53% of modelled night
Condensation
High

Warmth planning: As a broad starting point, consider a warm 3-season or 3–4 season bag with an ISO/EN comfort rating at or below about 0°C. Allow more margin if you sleep cold or expect fatigue, and use an adequate insulated mat. Dampness is possible, so keep the sleep system dry and ensure its insulation remains effective if damp.

Open-hillside reference. A sheltered pitch may be calmer; cols and ridges may be much windier. Tent design and the exact pitch still matter. Read about sleeping-bag comfort ratings, pitching in strong winds or using the wild-camping forecast.

Did this match your night?Share a quick observation to help improve this beta forecast.Give feedback

Approximate height is enough, please do not share an exact wild-camp location.

Daytime · exposed rockClimbing & scramblingBetaPoor conditions for exposed scrambling: gusts of 25–35 mph. Poor26 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Poor conditions for exposed scrambling. The rock is likely to be wet and slippery through the day. Gusts of 25–35 mph could throw you off balance on exposed moves and ridges. Cloud on the tops may make route-finding and retreat harder. The rock around the summit is mostly basalt, a dark volcanic rock. It grips well when dry and can be very slippery when wet. It is often blocky and shattered, with loose rubble on ledges. On the usual routes up you may also cross volcanic tuff, which is rough and grippy when dry and usually still grips reasonably when wet. On the usual routes up you may also cross mudstone or slate, which has only fair grip even when dry and is slippery when wet. These are general notes for each rock type, taken from geological maps around the summit, so the rock on your line may differ.

Rock surfaceWet rock likelyPeak gust25-35 mphRain5.0 mm
Main factorsgusts of 25–35 mphwet rock likelymuch of the route may be in cloud
Representative rock around the summit and along available routes Basalt Bedded Pyroclastic Formation
Origin
Igneous
Broad rock-response group
Volcanic rock
Mapping
BGS Geology 50K · 1:50,000
Summit area
Volcanic rock in 100% of 17 BGS samples within 350 m
Rock-response profile
Low confidence
View the summit BGS record

Basalt is a dark volcanic rock. It grips well when dry and can be very slippery when wet. It is often blocky and shattered, with loose rubble on ledges. These are general notes for each rock type, from geological map samples at and around the summit. The rock on your line can differ, and lichen, vegetation and seepage all change how it feels underfoot.

Rock groups along the sampled routes

These are mapped rock groups, not separate weather forecasts or a ranking of route safety.

Snowdon Horseshoe

volcanic rock

Snowdon Llanberis

volcanic rock, slate or mudstone

Snowdon Miners Track

volcanic rock

Snowdon Pyg Track

volcanic rock

Snowdon Ranger Path

volcanic rock, sandstone or gritstone

Geological detail and BGS records
Mapped variation

10 rock types appear in the mapped samples

Samples around the summit inform the main rock-response profile, with the summit pin shown separately where it differs. Route samples add further context, but this is not a continuous geological survey.

Summit-area sample Basalt Bedded Pyroclastic Formation 870–964 m samples Seen on Peak Snowdon Miners Track, Peak Snowdon Pyg Track

Basalt is a dark volcanic rock. It grips well when dry and can be very slippery when wet. It is often blocky and shattered, with loose rubble on ledges.

BGS record
Summit-area sample Pyroclastic rock Bedded Pyroclastic Formation 449–1,040 m samples Seen on Peak Snowdon Horseshoe, Peak Snowdon Llanberis, Peak Snowdon Miners Track and 2 more

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record
Summit-area sample Rhyolite Unnamed Igneous Intrusion, Ordovician 460–955 m samples Seen on Peak Snowdon Horseshoe, Peak Snowdon Miners Track, Peak Snowdon Pyg Track and 1 more

Rhyolite is a hard, fine-grained volcanic rock. It grips well when dry and gets slippery on smoother faces when wet. It is hard, but often cracked into sharp, blocky pieces, so some holds are loose.

BGS record
Route sample Felsic tuff Lower Rhyolitic Tuff Formation 447–705 m samples Seen on Peak Snowdon Miners Track, Peak Snowdon Ranger Path

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record
Route sample Mudstone and siltstone Cwm Eigiau Formation Around 580 m Seen on Peak Snowdon Llanberis

Mudstone or slate is a soft, fine-grained rock that splits into thin flakes. It has only fair grip even when dry and is slippery when wet. It is often shattered, breaking into loose flakes, scree and poor holds.

BGS record
Route sample Sandstone Llewelyn Volcanic Group Around 483 m Seen on Peak Snowdon Ranger Path

Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away.

BGS record
Route sample Sandstone Cwm Eigiau Formation Around 600 m Seen on Peak Snowdon Ranger Path

Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away.

BGS record
Route sample Siltstone Nant Ffrancon Subgroup Around 462 m Seen on Peak Snowdon Llanberis

Mudstone or slate is a soft, fine-grained rock that splits into thin flakes. It has only fair grip even when dry and is slippery when wet. It is often shattered, breaking into loose flakes, scree and poor holds.

BGS record
Route sample Tuff and sandstone Bedded Pyroclastic Formation Around 687 m Seen on Peak Snowdon Llanberis

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record
Summit-area sample Felsic tuff Upper Rhyolitic Tuff Formation

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record

Generic exposed scrambling terrain; BGS summit-area bedrock samples are included where available, but route grade, exact rock, polish, drainage and escape options remain unresolved. Contains British Geological Survey materials © UKRI 2026. How to use the climbing and scrambling forecast.

Did this match your experience?Tell us about the rock surface and wind to help improve this beta forecast.Give feedback

A broad surface report is enough; you do not need to identify a particular route.

Overnight · Aurora, stars & meteorsAfter darkBetaMostly cloudy, so little chance of seeing the stars. View forecastClose forecast

After dark: aurora and stargazing

Night beginning 2026-11-10. All times are UK local time.

Aurora outlook

Nothing notable expected.

A broad activity outlook, not a forecast of a visible display. Cloud and activity can change before the night.

Stargazing

Poor sky conditions during the best available spell: 11 Nov, 04:00 GMT to 05:00 GMT.

Mostly cloudy, so little chance of seeing the stars.

Moon-free dark sky: 10 Nov, 18:30 GMT to 11 Nov, 05:30 GMT.

Sky conditions through the night
Fully dark periods. Conditions can change between forecast hours.
TimeViewing conditions
10 Nov, 18:30 GMT to 19:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

10 Nov, 19:00 GMT to 20:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars.

10 Nov, 20:00 GMT to 21:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

10 Nov, 21:00 GMT to 22:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

10 Nov, 22:00 GMT to 23:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

10 Nov, 23:00 GMT to 11 Nov, 00:00 GMTPoor sky conditions

Some forecasts show clear spells, others keep it cloudy; check again nearer the time.

Forecast models disagree.

11 Nov, 00:00 GMT to 01:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

Limited model coverage.

11 Nov, 01:00 GMT to 02:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

Limited model coverage.

11 Nov, 02:00 GMT to 03:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

Limited model coverage.

11 Nov, 03:00 GMT to 04:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

Limited model coverage.

11 Nov, 04:00 GMT to 05:00 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

Limited model coverage.

11 Nov, 05:00 GMT to 05:30 GMTPoor sky conditions

Mostly cloudy, so little chance of seeing the stars.

Limited model coverage.

Moon, darkness and meteor showers

Near-new moon, about 3% illuminated.

Full darkness: 10 Nov, 18:30 GMT to 11 Nov, 05:30 GMT.

Moon times assume an open horizon. Hills can hide the Moon sooner. Moon-free does not mean cloud-free.

Southern Taurids are active on this night. Activity may be much lower away from the peak.

Northern Taurids are active on this night. Activity may be much lower away from the peak.

Leonids are active on this night. Activity may be much lower away from the peak.

  • Southern Taurids: peak around 10 October 2026.
  • Orionids: peak around 21 October 2026.
  • Northern Taurids: peak around 12 November 2026.
  • Leonids: peak around 18 November 2026.
  • Geminids: peak around 14 December 2026.
  • Ursids: peak around 22 December 2026.

Dates from the Royal Observatory Greenwich. Activity dates do not guarantee visible meteors. Look across a broad, dark sky, not only north.

Darkness of the surroundings

Estimated darkness rank 814 of 980 assessed peaks (1 is darkest), based on surrounding artificial light in 2021. This is not a measurement of tonight’s sky.

2021 artificial-light baseline, not measured sky brightness or a Bortle class. Changes to lighting, blue-rich LEDs, terrain screening, atmospheric scattering and cloud-reflected light are not resolved. Similar ranks are not meaningfully distinct. Darkness is not a recommendation to climb a summit at night.

VIIRS nighttime lights: Earth Observation Group, Payne Institute for Public Policy, Colorado School of Mines. Reprocessed by OpenGeoHub/OpenLandMap. Cropped and ranked by Mountain Weather.

Sky-weather grades exclude light pollution, terrain and thin haze. They are not mountain safety ratings. Check the mountain and camping forecast separately. Accessible lower viewpoints may be a better choice than summits.

Explore the dedicated aurora forecast, meteor shower forecast or dark-sky and astrophotography forecast.

Recommended kit for this dayWeather-aware packing prompts, plus your core hillwalking kitView kit

For a day hillwalk, not a complete route-specific checklist. Carry navigation and backup you can use, warm and waterproof layers, suitable footwear, food and water, a headtorch, emergency shelter, first aid and a way to call for help. Snow, ice, technical terrain and overnight trips need additional equipment and skills.

Does the weather shape your plans?Optional hill-user research. One answer helps; further questions are up to you.Take part

Help the Mountain Decisions Project understand how forecasts influence hill days, including when plans stay the same. Findings will be shared publicly as summaries, not individual responses.

This is about Crib y Ddysgl on Tuesday 10 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.

Open the questions to take part.

About the research and your privacy · Already been out? Share that experience instead

Confidence: Unavailable
Overall hill weather80Good
Summit wind · 08:00-17:0015-25 mph easterly Summit gusts · 08:00-17:0025-35 mph Feels like-6 to -2°C PrecipitationLittle or none Cloud-free summit estimate60% Freezing levelAbove summit DaylightSunrise 07:32 · Sunset 16:27 · 8.9 hours daylight

The day on the hill

A good day on Crib y Ddysgl: dry and breezy.

Wind

On the summit expect an easterly wind of 15–25 mph for most of the day, with gusts of 25–35 mph at the windiest. Gusts like that will be noticeable on ridges and open tops, and you will chill quickly when you stop.

Cloud and visibility

The tops are likely to stay mostly clear of cloud, though brief patches cannot be ruled out. The air should be clear, so expect far-reaching views whenever the tops come out of the cloud.

Rain and ground

It should stay dry. Some forecast models bring rain, so don't count on it staying dry.

Warmth and kit

On the tops it will be around 0 to 4°C, feeling like -6 to -2°C in the wind. The freezing level is above the summits. Take a hat, gloves, a windproof and a spare warm layer.

Daylight

A short day, with only about 9 hours of daylight. Sunset is around 4:25pm, so allow time to get off the hill before dark, and carry a head torch.

Forecast confidence

It's still seven days off and could change, so check again nearer the time.

Sunshine context Model-grid estimate, not summit sunshine

The surrounding model grid indicates 7.5 h of sunshine. This is not a forecast of time in sunshine on the summit. Use the cloud and views outlook above for the conditions on this mountain.

Early
2 h
Midday
3.9 h
Later
0 h

Overnight forecast: 17:00–08:00 (UK local time), in Wild camping below.

Morning · 08:00–12:00 Good Summit winds around 15-25 mph. Gusts around 25-35 mph are possible on exposed ground.
82
Afternoon · 12:00–17:00 Good Summit winds around 15-25 mph. Gusts around 25-35 mph are possible on exposed ground.
79

Compare an early start with later conditions. The main forecast above covers the day in more detail.

Overnight · 17:00–08:00Wild campingBetaA mixed night to camp, mainly because of damp air: gusts of about 30 mph. 59Mixed · 600 m View detailsHide details
Night beginning Wednesday 11 November 2026

Full overnight outlook

A mixed night to camp, mainly because of damp air. Gusts reach about 30 mph on open ground, so peg out well and use the guylines. Look for shelter from the east. It should stay dry. Up around 900 m you'd likely be in cloud for part of the night: damp, and hard to find your way if you need to move. The air is damp at every height we checked (300-900 m), so expect heavy condensation. Leave the vents open. A cold night, down to about 2°C around 900 m. A warm 3-season or 3–4 season bag rated to about 0°C comfort, and a warm mat, should do. Allow more if you sleep cold.

Overnight rain0.0 mm Open ground · 600 m16 mph · gusts 25 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 0°C or lower

Elevation reference (open ground)

300 m59 · mixed
Wind / gust
13 mph / 21 mph
Typical / low
4.2°C / 3.3°C · much of the night
In cloud
0% of modelled night
Condensation
High
600 m59 · mixed
Wind / gust
16 mph / 25 mph
Typical / low
4.2°C / 3.3°C · much of the night
In cloud
0% of modelled night
Condensation
High
900 m54 · mixed
Wind / gust
18 mph / 29 mph
Typical / low
3.0°C / 1.7°C · much of the night
In cloud
60% of modelled night
Condensation
High

Warmth planning: As a broad starting point, consider a warm 3-season or 3–4 season bag with an ISO/EN comfort rating at or below about 0°C. Allow more margin if you sleep cold or expect fatigue, and use an adequate insulated mat. Dampness is possible, so keep the sleep system dry and ensure its insulation remains effective if damp.

Open-hillside reference. A sheltered pitch may be calmer; cols and ridges may be much windier. Tent design and the exact pitch still matter. Read about sleeping-bag comfort ratings, pitching in strong winds or using the wild-camping forecast.

Did this match your night?Share a quick observation to help improve this beta forecast.Give feedback

Approximate height is enough, please do not share an exact wild-camp location.

Daytime · exposed rockClimbing & scramblingBetaGood conditions for exposed scrambling. Good75 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Good conditions for exposed scrambling. The rock should be drying, but damp patches, shaded holds and drainage lines may still be wet. Gusts of 25–35 mph could throw you off balance on exposed moves and ridges. The rock around the summit is mostly basalt, a dark volcanic rock. It grips well when dry and can be very slippery when wet. It is often blocky and shattered, with loose rubble on ledges. On the usual routes up you may also cross volcanic tuff, which is rough and grippy when dry and usually still grips reasonably when wet. On the usual routes up you may also cross mudstone or slate, which has only fair grip even when dry and is slippery when wet. These are general notes for each rock type, taken from geological maps around the summit, so the rock on your line may differ.

Rock surfaceDamp or dryingPeak gust25-35 mphRain0.0 mm
Main concerndamp or incompletely dried rock possible
Representative rock around the summit and along available routes Basalt Bedded Pyroclastic Formation
Origin
Igneous
Broad rock-response group
Volcanic rock
Mapping
BGS Geology 50K · 1:50,000
Summit area
Volcanic rock in 100% of 17 BGS samples within 350 m
Rock-response profile
Low confidence
View the summit BGS record

Basalt is a dark volcanic rock. It grips well when dry and can be very slippery when wet. It is often blocky and shattered, with loose rubble on ledges. These are general notes for each rock type, from geological map samples at and around the summit. The rock on your line can differ, and lichen, vegetation and seepage all change how it feels underfoot.

Rock groups along the sampled routes

These are mapped rock groups, not separate weather forecasts or a ranking of route safety.

Snowdon Horseshoe

volcanic rock

Snowdon Llanberis

volcanic rock, slate or mudstone

Snowdon Miners Track

volcanic rock

Snowdon Pyg Track

volcanic rock

Snowdon Ranger Path

volcanic rock, sandstone or gritstone

Geological detail and BGS records
Mapped variation

10 rock types appear in the mapped samples

Samples around the summit inform the main rock-response profile, with the summit pin shown separately where it differs. Route samples add further context, but this is not a continuous geological survey.

Summit-area sample Basalt Bedded Pyroclastic Formation 870–964 m samples Seen on Peak Snowdon Miners Track, Peak Snowdon Pyg Track

Basalt is a dark volcanic rock. It grips well when dry and can be very slippery when wet. It is often blocky and shattered, with loose rubble on ledges.

BGS record
Summit-area sample Pyroclastic rock Bedded Pyroclastic Formation 449–1,040 m samples Seen on Peak Snowdon Horseshoe, Peak Snowdon Llanberis, Peak Snowdon Miners Track and 2 more

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record
Summit-area sample Rhyolite Unnamed Igneous Intrusion, Ordovician 460–955 m samples Seen on Peak Snowdon Horseshoe, Peak Snowdon Miners Track, Peak Snowdon Pyg Track and 1 more

Rhyolite is a hard, fine-grained volcanic rock. It grips well when dry and gets slippery on smoother faces when wet. It is hard, but often cracked into sharp, blocky pieces, so some holds are loose.

BGS record
Route sample Felsic tuff Lower Rhyolitic Tuff Formation 447–705 m samples Seen on Peak Snowdon Miners Track, Peak Snowdon Ranger Path

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record
Route sample Mudstone and siltstone Cwm Eigiau Formation Around 580 m Seen on Peak Snowdon Llanberis

Mudstone or slate is a soft, fine-grained rock that splits into thin flakes. It has only fair grip even when dry and is slippery when wet. It is often shattered, breaking into loose flakes, scree and poor holds.

BGS record
Route sample Sandstone Llewelyn Volcanic Group Around 483 m Seen on Peak Snowdon Ranger Path

Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away.

BGS record
Route sample Sandstone Cwm Eigiau Formation Around 600 m Seen on Peak Snowdon Ranger Path

Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away.

BGS record
Route sample Siltstone Nant Ffrancon Subgroup Around 462 m Seen on Peak Snowdon Llanberis

Mudstone or slate is a soft, fine-grained rock that splits into thin flakes. It has only fair grip even when dry and is slippery when wet. It is often shattered, breaking into loose flakes, scree and poor holds.

BGS record
Route sample Tuff and sandstone Bedded Pyroclastic Formation Around 687 m Seen on Peak Snowdon Llanberis

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record
Summit-area sample Felsic tuff Upper Rhyolitic Tuff Formation

Volcanic tuff is rock formed from compacted volcanic ash and debris. It is rough and grippy when dry and usually still grips reasonably when wet. It is mostly solid, in slabs and ledges, though weathered patches can be crumbly.

BGS record

Generic exposed scrambling terrain; BGS summit-area bedrock samples are included where available, but route grade, exact rock, polish, drainage and escape options remain unresolved. Contains British Geological Survey materials © UKRI 2026. How to use the climbing and scrambling forecast.

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Weather data: Open-Meteo (CC BY 4.0). Adapted by Mountain Weather.

Forecast run: 2026-11-04

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