Mountain Weather

Gorllwyn weather forecast.

613 m summit in Mid Wales and Cambrian Mountains. 7 forecast days covering wind, cloud, rain and temperature, updated 9 November 2026 at 16:25 UTC.

Choose your hill day.

Compare 7 days, then read the outlook for your visit. Scores start at 100 and can fall below zero in severe weather. How we score a hill day.

Select a day to replace the detailed forecast below. 7 forecast days are available here.

Confidence: Medium
Overall hill weather42Poor
Summit wind · 08:00-17:0010-25 mph easterly Summit gusts · 08:00-17:0025-35 mph Feels like-6 to -2°C PrecipitationAround 2-5 mm Cloud-free summit estimate40% Cloud base through day500-800 m Freezing levelAbove summit DaylightSunrise 07:25 · Sunset 16:30 · 9.1 hours daylight

The day on the hill

A poor day on the tops of Gorllwyn, with drizzle arriving around midday and cloud coming and going on the summit.

Wind

On the summit expect an easterly wind of 10–25 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. A wind 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 400–700 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.

Rain and ground

Drizzle sets in around midday. Expect 2–5 mm in total. Some forecast models keep it drier through the middle of the day.

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. Pack waterproofs too, and keep a warm layer dry in your pack.

Daylight

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

Forecast confidence

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 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. Summit cloud is more persistent early in this period, with better prospects later.
37
Afternoon · 12:00–17:00 Poor Summit winds around 10-20 mph. Gusts around 20-30 mph are possible on exposed ground. Rain is forecast during this period.
46

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 rain: around 9 mm of rain. 44Poor · 600 m View detailsHide details
Night beginning Tuesday 10 November 2026

Full overnight outlook

A mixed night to camp, mainly because of the rain. Gusts reach about 25 mph on open ground, so peg out well and use the guylines. Look for shelter from the east. Expect a wet night, around 9 mm of rain, with rain while you pitch and still falling when you pack up. Up around 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 3°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 rain9.1 mm Open ground · 600 m17 mph · gusts 26 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 0°C or lower

Elevation reference (open ground)

300 m49 · mixed
Wind / gust
14 mph / 22 mph
Typical / low
4.9°C / 4.1°C · much of the night
In cloud
0% of modelled night
Condensation
High
600 m44 · mixed
Wind / gust
17 mph / 26 mph
Typical / low
3.9°C / 3.1°C · much of the night
In cloud
100% 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 & scramblingBetaVery poor conditions for exposed scrambling: wet, slippery rock. Poor0 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Very 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 sandstone, 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. 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 mphRain4.8 mm
Main factorswet rock likelymuch of the route may be in cloud
Representative rock around the summit Sandstone Yr Allt Formation
Origin
Sedimentary
Broad rock-response group
Sandstone or gritstone
Mapping
BGS Geology 50K · 1:50,000
Summit area
Sandstone or gritstone in 88% of 17 BGS samples within 350 m
Rock-response profile
High confidence
View the summit BGS record

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. 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.

Geological detail and BGS records
Mapped variation

2 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 Sandstone Yr Allt Formation

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
Summit-area sample Slumped mudstone, slumped siltstone and slumped sandstone Yr Allt Formation

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

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 darkBetaNight-sky guidance is unavailable for this night. View forecastClose forecast

After dark: aurora and stargazing

Night-sky guidance is unavailable for this night. This does not mean clear skies or no aurora.

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 Gorllwyn 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: Medium
Overall hill weather69Mixed
Summit wind · 08:00-17:0010-20 mph easterly Summit gusts · 08:00-17:0015-25 mph Feels like-4 to 0°C PrecipitationUp to around 2 mm Cloud-free summit estimate45% Cloud base through day400-1,500 m Freezing levelAbove summit DaylightSunrise 07:27 · Sunset 16:28 · 9.0 hours daylight

The day on the hill

A mixed day on Gorllwyn, with cloud coming and going on the summit.

Wind

On the summit expect an easterly wind of 10–20 mph for most of the day, with gusts of 15–25 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 around midday. The cloud base could be as low as 400–700 m early in the morning.

Rain and ground

Drizzle for much of the day. 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 -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. Pack waterproofs too, and keep a warm layer dry in your pack.

Daylight

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

Forecast confidence

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 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 Mixed Summit winds around 10-20 mph. Gusts around 15-25 mph are possible on exposed ground. Rain is forecast during this period. Rain is possible during the morning, but forecast models disagree on whether it will fall.
57
Afternoon · 12:00–17:00 Good Summit winds around 10-20 mph. Gusts around 15-25 mph are possible on exposed ground. Summit cloud becomes more persistent later. Rain is forecast during this period.
81

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: dry, with light winds. 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. Light winds on open ground, gusting no more than about 20 mph. It should stay dry. Up around 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 (300-600 m), so expect heavy condensation. Leave the vents open. A cold night, down to about 1°C around 600 m. A warm 3-season or 3–4 season bag rated to about -2°C comfort, and a warm mat, should do. Allow more if you sleep cold.

Overnight rain0.2 mm Open ground · 600 m13 mph · gusts 20 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about -2°C or lower

Elevation reference (open ground)

300 m59 · mixed
Wind / gust
11 mph / 16 mph
Typical / low
3.6°C / 1.7°C · much of the night
In cloud
0% of modelled night
Condensation
High
600 m59 · mixed
Wind / gust
13 mph / 20 mph
Typical / low
2.7°C / 0.8°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 -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 & scramblingBetaPoor conditions for exposed scrambling: wet, slippery rock. Poor20 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. Cloud on the tops may make route-finding and retreat harder. The rock around the summit is mostly sandstone, 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. 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 gust15-25 mphRain1.5 mm
Main factorswet rock likelymuch of the route may be in cloud
Representative rock around the summit Sandstone Yr Allt Formation
Origin
Sedimentary
Broad rock-response group
Sandstone or gritstone
Mapping
BGS Geology 50K · 1:50,000
Summit area
Sandstone or gritstone in 88% of 17 BGS samples within 350 m
Rock-response profile
High confidence
View the summit BGS record

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. 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.

Geological detail and BGS records
Mapped variation

2 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 Sandstone Yr Allt Formation

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
Summit-area sample Slumped mudstone, slumped siltstone and slumped sandstone Yr Allt Formation

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

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 darkBetaNight-sky guidance is unavailable for this night. View forecastClose forecast

After dark: aurora and stargazing

Night-sky guidance is unavailable for this night. This does not mean clear skies or no aurora.

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 Gorllwyn on Wednesday 11 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 weather98Excellent
Summit wind · 08:00-17:0010-20 mph northeasterly Summit gusts · 08:00-17:0015-25 mph Feels like-8 to -4°C PrecipitationLittle or none Cloud-free summit estimate90% Freezing level500-800 m DaylightSunrise 07:28 · Sunset 16:27 · 9.0 hours daylight

The day on the hill

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

Wind

On the summit expect a north-easterly wind of 10–20 mph for most of the day, with gusts of 15–25 mph at the windiest.

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 as long as the tops stay clear.

Rain and ground

It should stay dry.

Warmth and kit

On the tops it will be around -2 to 2°C, feeling like -8 to -4°C in the wind. The freezing level is close to summit height. 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

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 8.1 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
Less than 1 hour

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

Morning · 08:00–12:00 Excellent Summit winds around 10-20 mph. Gusts around 15-25 mph are possible on exposed ground.
99
Afternoon · 12:00–17:00 Excellent Summit winds around 10-20 mph. Gusts around 15-25 mph are possible on exposed ground.
97

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

Overnight · 17:00–08:00Wild campingBetaA poor night to camp on open ground: a frost, down to -1°C. 39Poor · 600 m View detailsHide details
Night beginning Thursday 12 November 2026

Full overnight outlook

A poor night to camp on open ground. Gusts reach about 25 mph on open ground, so peg out well and use the guylines. Look for shelter from the north. It should stay dry. A frost up around 600 m, down to about -1°C. A warm 3-season or 3–4 season bag rated to about -4°C comfort, and a warm mat, should do. Allow more if you sleep cold.

Overnight rain0.0 mm Open ground · 600 m14 mph · gusts 26 mph Morning pack-upNo wet signal Sleeping-bag warmthISO comfort rating about -4°C or lower

Moon overnight

Waxing crescent moon

Illuminated disc
13%
Moonrise
Outside this window
Moonset
17:50 GMT

Clear spells may allow a view of the Moon. Illumination describes the sunlit part of the Moon, not brightness at your pitch.

Overnight window: 12 Nov, 17:00 GMT to 13 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
12 mph / 22 mph
Typical / low
2.2°C / 0.8°C · much of the night
In cloud
0% of modelled night
Condensation
Low
600 m39 · poor
Wind / gust
14 mph / 26 mph
Typical / low
-0.1°C / -0.7°C · much of the night
In cloud
0% of modelled night
Condensation
Low

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 -4°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 sandstone, 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. 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 gust15-25 mphRain0.0 mm
Representative rock around the summit Sandstone Yr Allt Formation
Origin
Sedimentary
Broad rock-response group
Sandstone or gritstone
Mapping
BGS Geology 50K · 1:50,000
Summit area
Sandstone or gritstone in 88% of 17 BGS samples within 350 m
Rock-response profile
High confidence
View the summit BGS record

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. 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.

Geological detail and BGS records
Mapped variation

2 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 Sandstone Yr Allt Formation

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
Summit-area sample Slumped mudstone, slumped siltstone and slumped sandstone Yr Allt Formation

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

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 darkBetaNight-sky guidance is unavailable for this night. View forecastClose forecast

After dark: aurora and stargazing

Night-sky guidance is unavailable for this night. This does not mean clear skies or no aurora.

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 Gorllwyn on Thursday 12 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: High
Overall hill weather100Excellent
Summit wind · 08:00-17:000-15 mph northerly Summit gusts · 08:00-17:0010-20 mph Feels like-6 to -2°C PrecipitationLittle or none Cloud-free summit estimate90% Freezing level500-800 m DaylightSunrise 07:30 · Sunset 16:25 · 8.9 hours daylight

The day on the hill

A fine day on Gorllwyn: 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 northerly, with gusts of 10–20 mph at the windiest.

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 as long as the tops stay clear.

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

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 three days off, 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 10-20 mph are possible on exposed ground.
100
Afternoon · 12:00–17:00 Excellent Summit winds around 0-10 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 mixed night to camp, mainly because of the cold: dry, with light winds. 59Mixed · 600 m View detailsHide details
Night beginning Friday 13 November 2026

Full overnight outlook

A mixed night to camp, mainly because of the cold. Light winds on open ground, gusting no more than about 20 mph. It should stay dry. A cold night, down to about 3°C around 300 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 m7 mph · gusts 18 mph Morning pack-upNo wet signal Sleeping-bag warmthISO comfort rating about 0°C or lower

Moon overnight

Waxing crescent moon

Illuminated disc
20%
Moonrise
Outside this window
Moonset
18:51 GMT

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

Overnight window: 13 Nov, 17:00 GMT to 14 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 / 15 mph
Typical / low
3.1°C / 2.7°C · much of the night
In cloud
0% of modelled night
Condensation
Low
600 m59 · mixed
Wind / gust
7 mph / 18 mph
Typical / low
3.1°C / 2.7°C · much of the night
In cloud
0% of modelled night
Condensation
Low

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 & scramblingBetaExcellent conditions for exposed scrambling. Excellent95 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Excellent 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 sandstone, 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. 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 Sandstone Yr Allt Formation
Origin
Sedimentary
Broad rock-response group
Sandstone or gritstone
Mapping
BGS Geology 50K · 1:50,000
Summit area
Sandstone or gritstone in 88% of 17 BGS samples within 350 m
Rock-response profile
High confidence
View the summit BGS record

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. 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.

Geological detail and BGS records
Mapped variation

2 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 Sandstone Yr Allt Formation

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
Summit-area sample Slumped mudstone, slumped siltstone and slumped sandstone Yr Allt Formation

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

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 darkBetaNight-sky guidance is unavailable for this night. View forecastClose forecast

After dark: aurora and stargazing

Night-sky guidance is unavailable for this night. This does not mean clear skies or no aurora.

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 Gorllwyn on Friday 13 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 weather96Excellent
Summit wind · 08:00-17:0010-20 mph southwesterly Summit gusts · 08:00-17:0015-25 mph Feels like-4 to 0°C PrecipitationUp to around 2 mm Cloud-free summit estimate90% Freezing levelAbove summit DaylightSunrise 07:32 · Sunset 16:24 · 8.9 hours daylight

The day on the hill

A fine day on Gorllwyn: light winds and clear tops for most of the day.

Wind

On the summit expect a south-westerly wind of 10–20 mph for most of the day, with gusts of 15–25 mph at the windiest.

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 as long as the tops stay clear.

Rain and ground

A little rain at times.

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

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

Cloud heights are particularly hard to pin down today. 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 Excellent Summit winds around 10-20 mph. Gusts around 15-25 mph are possible on exposed ground.
97
Afternoon · 12:00–17:00 Excellent Summit winds around 10-20 mph. Gusts around 15-25 mph are possible on exposed ground. Rain is forecast during this period.
96

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

Overnight · 17:00–08:00Wild campingBetaA poor night to camp on open ground: gusts of about 35 mph. 39Poor · 600 m View detailsHide details
Night beginning Saturday 14 November 2026

Full overnight outlook

A poor night to camp on open ground. Gusts reach about 35 mph on open ground, so peg out well and use the guylines. Look for shelter from the southwest. Dry to pitch, then some light rain overnight and into the morning, so expect to pack a wet tent. Up around 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 (300-600 m), so expect heavy condensation. Leave the vents open. A cold night, down to about 3°C around 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 rain1.5 mm Open ground · 600 m22 mph · gusts 34 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 0°C or lower

Moon overnight

Waxing crescent moon

Illuminated disc
27%
Moonrise
Outside this window
Moonset
20:00 GMT

Cloud at the reference camping height may hide the Moon. Illumination describes the sunlit part of the Moon, not brightness at your pitch.

Overnight window: 14 Nov, 17:00 GMT to 15 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
18 mph / 28 mph
Typical / low
3.7°C / 3.3°C · much of the night
In cloud
0% of modelled night
Condensation
High
600 m39 · poor
Wind / gust
22 mph / 34 mph
Typical / low
3.4°C / 2.8°C · much of the night
In cloud
47% 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 & scramblingBetaMixed conditions for exposed scrambling: wet, slippery rock. Poor45 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Mixed conditions for exposed scrambling. The rock is likely to be wet and slippery through the day. The rock around the summit is mostly sandstone, 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. 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 gust15-25 mphRain0.3 mm
Main concernwet rock likely
Representative rock around the summit Sandstone Yr Allt Formation
Origin
Sedimentary
Broad rock-response group
Sandstone or gritstone
Mapping
BGS Geology 50K · 1:50,000
Summit area
Sandstone or gritstone in 88% of 17 BGS samples within 350 m
Rock-response profile
High confidence
View the summit BGS record

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. 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.

Geological detail and BGS records
Mapped variation

2 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 Sandstone Yr Allt Formation

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
Summit-area sample Slumped mudstone, slumped siltstone and slumped sandstone Yr Allt Formation

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

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 darkBetaNight-sky guidance is unavailable for this night. View forecastClose forecast

After dark: aurora and stargazing

Night-sky guidance is unavailable for this night. This does not mean clear skies or no aurora.

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 Gorllwyn on Saturday 14 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 weather29Poor
Summit wind · 08:00-17:0020-35 mph southwesterly Summit gusts · 08:00-17:0035-45 mph Feels like-2 to 2°C PrecipitationAround 2-5 mm Cloud-free summit estimate30% Cloud base through day500-800 m Freezing levelAbove summit DaylightSunrise 07:34 · Sunset 16:22 · 8.8 hours daylight

The day on the hill

A poor day on the tops of Gorllwyn, with drizzle for much of the day and a blustery wind.

Things to watch

Burns could rise quickly through the day and overnight. Timings are rough. Turn back if a crossing looks unsafe.

Wind

On the summit expect a south-westerly wind of 20–35 mph for most of the day, 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. If the windier forecast models are right, summit gusts could reach 55–65 mph.

Cloud and visibility

Expect the summit to be in cloud for most of the day. The cloud base could be as low as 400–700 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. 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 4 to 8°C, feeling like -2 to 2°C in the wind. The freezing level is above the summits. A windproof and an extra layer for stops will help. 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 4:20pm, so allow time to get off the hill before dark, and carry a head torch.

Forecast confidence

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 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 20-30 mph. Gusts around 30-40 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.
34
Afternoon · 12:00–17:00 Poor Summit winds around 25-35 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. Rain is forecast during this period. Some forecast models bring rain during the afternoon, while others keep it mostly dry.
24

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

Overnight · 17:00–08:00Wild campingBetaNot a night to camp on the open hill: gusts of about 55 mph and around 14 mm of rain. 9Poor · 600 m View detailsHide details
Night beginning Sunday 15 November 2026

Full overnight outlook

Not a night to camp on the open hill. Gusts reach about 55 mph on open ground, enough to damage a tent on open ground. Don't count on finding shelter once you're up there. Choose another night or a low, sheltered spot. The wind swings from southwesterly to westerly overnight, so a pitch sheltered at dusk may not be by morning. Expect a wet night, around 14 mm of rain, mostly early on, so you'll likely pitch in the rain. Up around 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 3°C at 300 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 rain14.4 mm Open ground · 600 m31 mph · gusts 54 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 0°C or lower

Moon overnight

Waxing crescent moon

Illuminated disc
36%
Moonrise
Outside this window
Moonset
21:13 GMT

Cloud at the reference camping height may hide the Moon. Illumination describes the sunlit part of the Moon, not brightness at your pitch.

Overnight window: 15 Nov, 17:00 GMT to 16 Nov, 08:00 GMT. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.

Elevation reference (open ground)

300 m19 · very poor
Wind / gust
26 mph / 45 mph
Typical / low
9.4°C / 3.1°C · several hours
In cloud
0% of modelled night
Condensation
High
600 m9 · very poor
Wind / gust
31 mph / 54 mph
Typical / low
6.7°C / 3.1°C · several hours
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 & scramblingBetaVery poor conditions for exposed scrambling: gusts of 35–45 mph. Poor2 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Very poor conditions for exposed scrambling. The rock is likely to be wet and slippery through the day. 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 sandstone, 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. 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 gust35-45 mphRain8.1 mm
Main factorsgusts of 35–45 mphwet rock likelymuch of the route may be in cloud
Representative rock around the summit Sandstone Yr Allt Formation
Origin
Sedimentary
Broad rock-response group
Sandstone or gritstone
Mapping
BGS Geology 50K · 1:50,000
Summit area
Sandstone or gritstone in 88% of 17 BGS samples within 350 m
Rock-response profile
High confidence
View the summit BGS record

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. 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.

Geological detail and BGS records
Mapped variation

2 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 Sandstone Yr Allt Formation

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
Summit-area sample Slumped mudstone, slumped siltstone and slumped sandstone Yr Allt Formation

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

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 darkBetaNight-sky guidance is unavailable for this night. View forecastClose forecast

After dark: aurora and stargazing

Night-sky guidance is unavailable for this night. This does not mean clear skies or no aurora.

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 Gorllwyn on Sunday 15 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 weather91Excellent
Summit wind · 08:00-17:005-20 mph southwesterly Summit gusts · 08:00-17:0020-30 mph Feels like-4 to 0°C PrecipitationLittle or none Cloud-free summit estimate90% Freezing levelAbove summit DaylightSunrise 07:36 · Sunset 16:21 · 8.8 hours daylight

The day on the hill

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

Wind

On the summit expect a south-westerly wind of 5–20 mph for most of the day, with gusts of 20–30 mph at the windiest. Lower down on the open hillside the wind will be light, under 10 mph.

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 as long as the tops stay clear.

Rain and ground

It should stay dry. Some forecast models bring rain, so don't count on it staying dry. It will be wet underfoot after recent rain.

Warmth and kit

On the tops it will be around 2 to 6°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

A short day, with only about 9 hours of daylight. Sunset is around 4:20pm, 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 7.6 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
1.9 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 10-20 mph early in the morning, easing to 0-10 mph later. Gusts around 20-30 mph are possible on exposed ground.
90
Afternoon · 12:00–17:00 Excellent Summit winds around 5-15 mph. Gusts around 10-20 mph are possible on exposed ground.
92

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

Overnight · 17:00–08:00Wild campingBetaNot a night to camp on the open hill: gusts of about 50 mph and around 10 mm of rain. 9Poor · 600 m View detailsHide details
Night beginning Monday 16 November 2026

Full overnight outlook

Not a night to camp on the open hill. Gusts reach about 50 mph on open ground, enough to damage a tent on open ground. Don't count on finding shelter once you're up there. Choose another night or a low, sheltered spot. The wind swings from southerly to westerly overnight, so a pitch sheltered at dusk may not be by morning. Expect a wet night, around 10 mm of rain, with rain while you pitch and still falling when you pack up. Up around 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 5°C at 300 m. A 3-season bag rated to about 2°C comfort, and a warm mat, should do. Allow more if you sleep cold.

Overnight rain10.2 mm Open ground · 600 m22 mph · gusts 49 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 2°C or lower

Moon overnight

First-quarter moon

Illuminated disc
46%
Moonrise
Outside this window
Moonset
22:27 GMT

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

Overnight window: 16 Nov, 17:00 GMT to 17 Nov, 08:00 GMT. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.

Elevation reference (open ground)

300 m19 · very poor
Wind / gust
18 mph / 40 mph
Typical / low
9.2°C / 4.6°C · a brief spell
In cloud
0% of modelled night
Condensation
High
600 m9 · very poor
Wind / gust
22 mph / 49 mph
Typical / low
7.9°C / 4.6°C · a brief spell
In cloud
67% 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 & scramblingBetaFair conditions for exposed scrambling. Good70 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Fair conditions for exposed scrambling. After recent rain the rock may still be wet in places, especially shaded holds and drainage lines. Gusts of 20–30 mph will be noticeable on exposed ridges. The rock around the summit is mostly sandstone, 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. 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 overhead; seepage uncertainPeak gust20-30 mphRain0.4 mm
Main concerndamp or incompletely dried rock possible
Representative rock around the summit Sandstone Yr Allt Formation
Origin
Sedimentary
Broad rock-response group
Sandstone or gritstone
Mapping
BGS Geology 50K · 1:50,000
Summit area
Sandstone or gritstone in 88% of 17 BGS samples within 350 m
Rock-response profile
High confidence
View the summit BGS record

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. 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.

Geological detail and BGS records
Mapped variation

2 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 Sandstone Yr Allt Formation

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
Summit-area sample Slumped mudstone, slumped siltstone and slumped sandstone Yr Allt Formation

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

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 darkBetaNight-sky guidance is unavailable for this night. View forecastClose forecast

After dark: aurora and stargazing

Night-sky guidance is unavailable for this night. This does not mean clear skies or no aurora.

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 Gorllwyn on Monday 16 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

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

Forecast run: 2026-11-09

A forecast is part of the decision.

Mountain weather can differ sharply from conditions in the valley. Check official warnings, carry appropriate navigation and clothing, and be ready to change the plan. Read how Mountain Weather forecasts are produced and where their limits lie.

Choose another summit