Ben Macdui (Beinn Macduibh) Weather Forecast

Wednesday 21 October 2026Confidence: High

Overall hill weather24Poor

Summit wind · 08:00-17:005-25 mph westerly Summit gusts · 08:00-17:0025-35 mph Feels like-10 to -6°C PrecipitationAround 5-10 mm Cloud-free summit estimate10% Cloud base through day300-600 m Freezing level1,000-1,300 m DaylightSunrise 08:00 · Sunset 17:57 · 9.9 hours daylight

The day on the hill

A poor day on the tops of Ben Macdui, with sleet or snow up high and the summit in cloud for most of the day.

Wind

On the summit expect a westerly wind of 5–25 mph for most of the day, with gusts of 25–35 mph at the windiest. The wind turns westerly in the early afternoon. 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 300–600 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

Sleet or snow is possible on the tops. Rain for much of the day. Expect 5–10 mm in total, measured as melted water, so any snow would lie deeper.

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 falls through the day, to around 1200–1500 m by mid-afternoon. 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 5:55pm, so allow time to get off the hill before dark, and carry a head torch.

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 5-20 mph. Gusts around 15-25 mph are possible on exposed ground. Rain is forecast during this period.

30

Afternoon · 12:00–17:00 Poor More rain is expected. Summit winds around 5-15 mph in the early afternoon, strengthening to 15-25 mph later. Gusts around 25-35 mph are possible on exposed ground. Rain is forecast during this period.

18

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: a frost, down to 0°C. 47Poor · 600 m View detailsHide details

Night beginning Wednesday 21 October 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 west. Expect some light rain, mostly early on, so you'll likely pitch in the rain. 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 frost up around 900 m, down to about 0°C. 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 rain1.3 mm Open ground · 600 m18 mph · gusts 28 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about -2°C or lower

Moon overnight

Waxing gibbous moon

Illuminated disc: 80%
Moonrise: Outside this window
Moonset: 02:54 next morning BST

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: 21 Oct, 17:00 BST to 22 Oct, 08:00 BST. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.

Elevation reference (open ground)

300 m59 · mixed

Wind / gust: 15 mph / 23 mph
Typical / low: 3.2°C / 2.8°C · much of the night
In cloud: 0% of modelled night
Condensation: High

600 m47 · mixed

Wind / gust: 18 mph / 28 mph
Typical / low: 2.1°C / 1.7°C · much of the night
In cloud: 80% of modelled night
Condensation: High

900 m39 · poor

Wind / gust: 22 mph / 32 mph
Typical / low: 0.1°C / -0.3°C · much of the night
In cloud: 80% 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

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. Icy patches are likely on the rock, which makes it treacherous without winter kit. 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 granite, a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings. 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 mphRain9.3 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 Biotite granite Cairngorm Pluton, Phase 2

Origin: Igneous
Broad rock-response group: Granite, gneiss or gabbro
Mapping: BGS Geology 50K · 1:50,000
Summit area: Granite, gneiss or gabbro in 100% of 17 BGS samples within 350 m
Rock-response profile: Moderate confidence

View the summit BGS record

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings. 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.

Ben Macdui and Derry Cairngorm

granite, gneiss or gabbro

Ben Macdui and Cairn Gorm

granite, gneiss or gabbro

Geological detail and BGS records

Mapped variation

3 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 Biotite granite Cairngorm Pluton, Phase 2 1,071–1,309 m samples Seen on Ben Macdui and Derry Cairngorm, Ben Macdui and Cairn Gorm

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings.

BGS record

Route sample Porphyritic granite Cairngorm Pluton, Phase 2 733–958 m samples Seen on Ben Macdui and Derry Cairngorm

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings.

BGS record

Route sample Granite Cairngorm Pluton, Phase 2 Around 1,138 m Seen on Ben Macdui and Cairn Gorm

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings.

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

Overnight · Aurora, stars & meteorsAfter darkBetaMostly clear. View forecastClose forecast

After dark: aurora and stargazing

Night beginning 2026-10-21. 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 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

Good sky conditions during the best available spell: 22 Oct, 05:00 BST to 05:55 BST.

Mostly clear.

Moon-free dark sky: 22 Oct, 02:50 BST to 05:55 BST.

Sky conditions through the night

Fully dark periods. Conditions can change between forecast hours.
Time	Viewing conditions
21 Oct, 20:05 BST to 21:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Moonlight washes out the fainter stars. Limited model coverage.
21 Oct, 21:00 BST to 22:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
21 Oct, 22:00 BST to 23:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
21 Oct, 23:00 BST to 22 Oct, 00:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
22 Oct, 00:00 BST to 01:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Moonlight washes out the fainter stars. Limited model coverage.
22 Oct, 01:00 BST to 02:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Limited model coverage.
22 Oct, 02:00 BST to 03:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. Limited model coverage.
22 Oct, 03:00 BST to 04:00 BST	Mixed sky conditions Some breaks in the cloud, so stars at times. Limited model coverage.
22 Oct, 04:00 BST to 05:00 BST	Good sky conditions Mostly clear. Limited model coverage.
22 Oct, 05:00 BST to 05:55 BST	Good sky conditions Mostly clear. Limited model coverage.

Moon, darkness and meteor showers

Gibbous moon, about 80% illuminated.

Moonset around 22 Oct, 02:50 BST.

Full darkness: 21 Oct, 20:05 BST to 22 Oct, 05:55 BST.

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 315 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 Ben Macdui on Wednesday 21 October 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

Thursday 22 October 2026Confidence: Medium

Overall hill weather70Good

Summit wind · 08:00-17:0010-25 mph westerly Summit gusts · 08:00-17:0020-30 mph Feels like-12 to -8°C PrecipitationLittle or none Cloud-free summit estimate60% Cloud base through day400-1,900 m Freezing level800-1,100 m DaylightSunrise 08:02 · Sunset 17:55 · 9.9 hours daylight

The day on the hill

A good day on Ben Macdui, though expect a bitter wind chill.

Wind

On the summit expect a westerly wind of 10–25 mph for most of the day, with gusts of 20–30 mph at the windiest. Lower down on the open hillside it will be more like 5–15 mph.

Cloud and visibility

Cloud on the tops early should lift off them by mid-morning. The cloud base could be as low as 400–700 m early in the morning. Good spells of sunshine are likely. 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. It will be wet underfoot after recent rain.

Warmth and kit

On the tops it will be around -4 to 0°C, feeling like -12 to -8°C in the wind. The freezing level is around 900–1200 m, so it will be below freezing on the tops. Hat, gloves and a warm insulated layer are essential, with extra warmth for stops.

Daylight

Sunset is around 5:55pm, 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. 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 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: 1 h
Midday: 3.7 h
Later: 1.8 h

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

Morning · 08:00–12:00 Mixed Summit winds around 15-25 mph. Gusts around 20-30 mph are possible on exposed ground.

50

Afternoon · 12:00–17:00 Excellent Summit winds around 10-20 mph. Gusts around 20-30 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 the wind: gusts of about 35 mph. 52Mixed · 600 m View detailsHide details

Night beginning Thursday 22 October 2026

Full overnight outlook

A mixed night to camp, mainly because of the wind. Gusts reach about 35 mph around 900 m and nearer 25 mph around 300 m, so peg out well and use the guylines. Look for shelter from the southwest. The wind swings from southwesterly to southeasterly overnight, so a pitch sheltered at dusk may not be by morning. Dry to pitch, then some light rain by morning, so you'll likely pack up in the wet. 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 rain1.4 mm Open ground · 600 m14 mph · gusts 29 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 0°C or lower

Moon overnight

Waxing gibbous moon

Illuminated disc: 88%
Moonrise: Outside this window
Moonset: 04:19 next morning BST

Views of the Moon may come and go through cloud breaks. Illumination describes the sunlit part of the Moon, not brightness at your pitch.

Overnight window: 22 Oct, 17:00 BST to 23 Oct, 08:00 BST. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.

Elevation reference (open ground)

300 m59 · mixed

Wind / gust: 12 mph / 24 mph
Typical / low: 4.5°C / 4.0°C · much of the night
In cloud: 0% of modelled night
Condensation: High

600 m52 · mixed

Wind / gust: 14 mph / 29 mph
Typical / low: 3.5°C / 3.2°C · much of the night
In cloud: 13% of modelled night
Condensation: High

900 m39 · poor

Wind / gust: 17 mph / 34 mph
Typical / low: 1.6°C / 1.2°C · much of the night
In cloud: 20% 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

Daytime · exposed rockClimbing & scramblingBetaVery poor conditions for exposed scrambling. Poor0 View detailsHide details

Generic exposed-rock guidance

Full climbing & scrambling outlook

Very poor conditions for exposed scrambling. After recent rain the rock may still be wet in places, especially shaded holds and drainage lines. Icy patches are likely on the rock, which makes it treacherous without winter kit. Gusts of 20–30 mph will be noticeable on exposed ridges. Cloud on the tops may make route-finding and retreat harder. The rock around the summit is mostly granite, a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings. 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 mphRainPossible · 32%

Main factorsdamp or incompletely dried rock possibleSnow is likely to be lying on high ground. Scrambling may require winter mountaineering skills and equipment

Representative rock around the summit and along available routes Biotite granite Cairngorm Pluton, Phase 2

Origin: Igneous
Broad rock-response group: Granite, gneiss or gabbro
Mapping: BGS Geology 50K · 1:50,000
Summit area: Granite, gneiss or gabbro in 100% of 17 BGS samples within 350 m
Rock-response profile: Moderate confidence

View the summit BGS record

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings. 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.

Ben Macdui and Derry Cairngorm

granite, gneiss or gabbro

Ben Macdui and Cairn Gorm

granite, gneiss or gabbro

Geological detail and BGS records

Mapped variation

3 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 Biotite granite Cairngorm Pluton, Phase 2 1,071–1,309 m samples Seen on Ben Macdui and Derry Cairngorm, Ben Macdui and Cairn Gorm

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings.

BGS record

Route sample Porphyritic granite Cairngorm Pluton, Phase 2 733–958 m samples Seen on Ben Macdui and Derry Cairngorm

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings.

BGS record

Route sample Granite Cairngorm Pluton, Phase 2 Around 1,138 m Seen on Ben Macdui and Cairn Gorm

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings.

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

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

After dark: aurora and stargazing

Night beginning 2026-10-22. All times are UK local time.

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

Too quiet for a likely sighting from here. Activity peaks around Kp 2.7 (on a 0 to 9 scale). It would take about Kp 3.7 for a camera to pick up a glow low in the north, though that is not a hard line.

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

Stargazing

Poor sky conditions during the best available spell: 22 Oct, 20:00 BST to 21:00 BST.

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

Moon-free dark sky: 23 Oct, 04:15 BST to 05:55 BST.

Sky conditions through the night

Fully dark periods. Conditions can change between forecast hours.
Time	Viewing conditions
22 Oct, 20:00 BST to 21:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
22 Oct, 21:00 BST to 22:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
22 Oct, 22:00 BST to 23:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
22 Oct, 23:00 BST to 23 Oct, 00:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
23 Oct, 00:00 BST to 01:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
23 Oct, 01:00 BST to 02:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
23 Oct, 02:00 BST to 03:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
23 Oct, 03:00 BST to 04:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. Limited model coverage.
23 Oct, 04:00 BST to 05:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. Limited model coverage.
23 Oct, 05:00 BST to 05:55 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Limited model coverage.

Moon, darkness and meteor showers

Gibbous moon, about 88% illuminated.

Moonset around 23 Oct, 04:15 BST.

Full darkness: 22 Oct, 20:00 BST to 23 Oct, 05:55 BST.

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 315 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 Ben Macdui on Thursday 22 October 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

Friday 23 October 2026Confidence: Medium

Overall hill weather-12Severe hill conditions

Summit wind · 08:00-17:0015-30 mph easterly Summit gusts · 08:00-17:0030-40 mph Feels like-10 to -6°C PrecipitationAround 20-40 mm Cloud-free summit estimate15% Cloud base through day400-1,100 m Freezing level1,100-1,400 m DaylightSunrise 08:04 · Sunset 17:52 · 9.8 hours daylight

The day on the hill

Serious conditions on Ben Macdui, with burns likely to be in spate and sleet or snow up high. Think carefully before heading high.

Things to watch

Burns and rivers are likely to be in spate through the day and overnight, so unbridged crossings could be difficult or impossible. Timings are rough. Turn back if a crossing looks unsafe.

Snow and navigation

There is a risk of blizzard conditions in the morning, when snow and strong winds coincide. Paths and footprints can quickly disappear beneath falling and blowing snow. Snow may collect in deeper drifts in hollows, behind boulders and on slopes sheltered from the wind. Exposed ground may be scoured while nearby drifts deepen. Wind-loaded slopes can also be avalanche terrain. Check the local avalanche forecast where one is available; this is not an assessment of slope stability.

Wind

On the summit expect an easterly wind of 15–30 mph for most of the day, with gusts of 30–40 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. If the windier forecast models are right, summit gusts could reach 45–55 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 early in the 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. Visibility may drop briefly in showers. Mist or fog is possible in the valleys early on, clearing by about 2am. Where snow covers the ground, the sky and hillside can merge into a featureless white view, making it difficult to judge slope or direction. Do not rely on following a visible path. Avoid exposed routes if you cannot navigate safely in these conditions, and turn back before visibility deteriorates.

Rain and ground

Sleet and snow for much of the day, becoming heavier through the afternoon. Expect 20–40 mm in total, measured as melted water, so any snow would lie deeper. Totals are uncertain and could be higher. It will be wet underfoot after recent rain.

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 close to summit height. 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 5:50pm, so allow time to get off the hill before dark, and carry a head torch.

Forecast confidence

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

Below zero means severe hill conditions. More negative scores indicate more severe forecast weather. Read the hazard details before making plans. Below zero means severe hill conditions. More negative scores indicate more severe forecast weather. Read the hazard details before making plans.

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 Severe hill conditions Summit winds around 20-30 mph. Gusts around 30-40 mph are possible on exposed ground. Gusts this strong can make walking into it hard work, with buffeting on ridges and edges. Summit cloud is more persistent early in this period, with better prospects later. Rain is forecast during this period. Rain is forecast during the morning, but models differ considerably on the amount.

-2

Afternoon · 12:00–17:00 Severe hill conditions More rain is expected. Summit winds around 25-35 mph in the early afternoon, easing to 15-25 mph later. Gusts around 30-40 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. Rain is forecast during the afternoon, but models differ considerably on the amount.

-22

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 and around 19 mm of rain. 36Poor · 600 m View detailsHide details

Night beginning Friday 23 October 2026

Full overnight outlook

A poor night to camp on open ground. Gusts reach about 35 mph around 900 m and nearer 25 mph around 300 m, which makes for a noisy, testing night even in a good tent. Look for shelter from the north. Expect a wet night, around 19 mm of rain, mostly early on, so you'll likely pitch in the rain. 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. 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 rain18.8 mm Open ground · 600 m16 mph · gusts 30 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 0°C or lower

Moon overnight

Waxing gibbous moon

Illuminated disc: 94%
Moonrise: Outside this window
Moonset: 05:46 next morning BST

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: 23 Oct, 17:00 BST to 24 Oct, 08:00 BST. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.

Elevation reference (open ground)

300 m39 · poor

Wind / gust: 14 mph / 25 mph
Typical / low: 3.5°C / 3.4°C · much of the night
In cloud: 0% of modelled night
Condensation: High

600 m36 · poor

Wind / gust: 16 mph / 30 mph
Typical / low: 2.7°C / 2.5°C · much of the night
In cloud: 100% of modelled night
Condensation: High

900 m28 · poor

Wind / gust: 19 mph / 35 mph
Typical / low: 0.8°C / 0.6°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

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. Icy patches are likely on the rock, which makes it treacherous without winter kit. Gusts of 30–40 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 granite, a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings. 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 gust30-40 mphRain25.3 mm

Main factorsgusts of 30–40 mphwet rock likelymuch of the route may be in cloud

Representative rock around the summit and along available routes Biotite granite Cairngorm Pluton, Phase 2

Origin: Igneous
Broad rock-response group: Granite, gneiss or gabbro
Mapping: BGS Geology 50K · 1:50,000
Summit area: Granite, gneiss or gabbro in 100% of 17 BGS samples within 350 m
Rock-response profile: Moderate confidence

View the summit BGS record

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings. 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.

Ben Macdui and Derry Cairngorm

granite, gneiss or gabbro

Ben Macdui and Cairn Gorm

granite, gneiss or gabbro

Geological detail and BGS records

Mapped variation

3 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 Biotite granite Cairngorm Pluton, Phase 2 1,071–1,309 m samples Seen on Ben Macdui and Derry Cairngorm, Ben Macdui and Cairn Gorm

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings.

BGS record

Route sample Porphyritic granite Cairngorm Pluton, Phase 2 733–958 m samples Seen on Ben Macdui and Derry Cairngorm

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings.

BGS record

Route sample Granite Cairngorm Pluton, Phase 2 Around 1,138 m Seen on Ben Macdui and Cairn Gorm

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings.

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

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

After dark: aurora and stargazing

Night beginning 2026-10-23. 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 3.3 (on a 0 to 9 scale).

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

Stargazing

Good sky conditions during the best available spell: 24 Oct, 05:00 BST to 06:00 BST.

Some breaks in the cloud, so stars at times.

Moon-free dark sky: 24 Oct, 05:40 BST to 06:00 BST.

Sky conditions through the night

Fully dark periods. Conditions can change between forecast hours.
Time	Viewing conditions
23 Oct, 20:00 BST to 21:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
23 Oct, 21:00 BST to 22:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
23 Oct, 22:00 BST to 23:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
23 Oct, 23:00 BST to 24 Oct, 00:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
24 Oct, 00:00 BST to 01:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
24 Oct, 01:00 BST to 02:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Moonlight washes out the fainter stars. Limited model coverage.
24 Oct, 02:00 BST to 03:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Moonlight washes out the fainter stars. Limited model coverage.
24 Oct, 03:00 BST to 04:00 BST	Poor sky conditions Some breaks in the cloud, so stars at times. Moonlight washes out the fainter stars. Limited model coverage.
24 Oct, 04:00 BST to 05:00 BST	Mixed sky conditions Mostly clear. Moonlight washes out the fainter stars. Limited model coverage.
24 Oct, 05:00 BST to 06:00 BST	Good sky conditions Some breaks in the cloud, so stars at times. Limited model coverage.

Moon, darkness and meteor showers

Gibbous moon, about 94% illuminated.

Moonset around 24 Oct, 05:40 BST.

Full darkness: 23 Oct, 20:00 BST to 24 Oct, 06:00 BST.

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 315 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 Ben Macdui on Friday 23 October 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

Saturday 24 October 2026Confidence: Low

Overall hill weather32Poor

Summit wind · 08:00-17:005-55 mph southwesterly Summit gusts · 08:00-17:0065-75 mph Feels like-14 to -10°C PrecipitationUp to around 2 mm Cloud-free summit estimate75% Cloud base through day400-1,700 m Freezing level900-1,200 m DaylightSunrise 08:06 · Sunset 17:50 · 9.7 hours daylight

The day on the hill

A poor day on the tops of Ben Macdui, with severe winds and sleet or snow up high.

Snow and navigation

There is a risk of blizzard conditions in the afternoon, when snow and strong winds coincide. Paths and footprints can quickly disappear beneath falling and blowing snow. Snow may collect in deeper drifts in hollows, behind boulders and on slopes sheltered from the wind. Exposed ground may be scoured while nearby drifts deepen. Wind-loaded slopes can also be avalanche terrain. Check the local avalanche forecast where one is available; this is not an assessment of slope stability.

Wind

On the summit expect a south-westerly wind of around 5–15 mph first thing, rising to 50–60 mph by mid-afternoon, with gusts of 65–75 mph at the windiest. The wind turns south-westerly mid-morning. Lower down on the open hillside it will be more like 10–30 mph. Gusts like that are strong enough to make movement extremely difficult on exposed ground. During the strongest gusts, walking or standing may be impossible and you could be blown off your feet. Avoid exposed high ground. If the windier forecast models are right, summit gusts could reach 85–95 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. The cloud base could be as low as 400–700 m mid-morning. Mist or fog is possible in the valleys during the morning, clearing by about 10am. It will look largely cloudy overhead, but that cloud should mostly stay above the tops. Where snow covers the ground, the sky and hillside can merge into a featureless white view, making it difficult to judge slope or direction. Do not rely on following a visible path. Avoid exposed routes if you cannot navigate safely in these conditions, and turn back before visibility deteriorates.

Rain and ground

Snow arrives mid-afternoon. Expect up to 2 mm in total, measured as melted water, so any snow would lie deeper. Totals are uncertain and could be higher. The ground is very wet after recent rain, so expect boggy paths.

Warmth and kit

On the tops it will be around -4 to 0°C, feeling like -14 to -10°C in the wind. It will feel colder later as the wind picks up. The freezing level is around 1000–1300 m, so it will be below freezing on the tops. Hat, gloves and a warm insulated layer are essential, with extra warmth for stops. Pack waterproofs too, and keep a warm layer dry in your pack.

Daylight

Sunset is around 5:50pm, 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. 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 3.4 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 h
Midday: 1.4 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 5-15 mph early in the morning, strengthening to 15-25 mph later. Gusts around 25-35 mph are possible on exposed ground. Summit cloud is more persistent early in this period, with better prospects later. Rain is possible during the morning, but forecast models disagree on whether it will fall.

64

Afternoon · 12:00–17:00 Poor Winds strengthen compared with the morning. Summit winds around 30-40 mph in the early afternoon, strengthening to 45-55 mph later. Gusts around 65-75 mph are possible on exposed ground. Gusts this strong can make movement extremely difficult on exposed ground. During the strongest gusts, walking or standing may be impossible and you could be blown off your feet. Avoid exposed high ground. Rain is forecast during this period. Some forecast models bring rain during the afternoon, while others keep it mostly dry.

0

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 85 mph and about 7 mm of rain. 0Poor · 600 m View detailsHide details

Night beginning Saturday 24 October 2026

Full overnight outlook

Not a night to camp on the open hill. Gusts reach about 85 mph around 900 m and nearer 60 mph around 300 m, strong enough to flatten or tear a tent. 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 about 7 mm of rain, with rain while you pitch and still falling when you pack up. 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. The ground will be sodden after recent rain, so pick a firm, well-drained pitch.

Overnight rain7.2 mm Open ground · 600 m49 mph · gusts 73 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 0°C or lower

Moon overnight

Near-full moon

Illuminated disc: 98%
Moonrise: Outside this window
Moonset: 06:18 next morning GMT

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

Overnight window: 24 Oct, 17:00 BST to 25 Oct, 08:00 GMT. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.

Elevation reference (open ground)

300 m0 · very poor

Wind / gust: 41 mph / 61 mph
Typical / low: 5.6°C / 4.7°C · a brief spell
In cloud: 0% of modelled night
Condensation: Moderate

600 m0 · very poor

Wind / gust: 49 mph / 73 mph
Typical / low: 3.7°C / 2.9°C · much of the night
In cloud: 0% of modelled night
Condensation: Moderate

900 m0 · very poor

Wind / gust: 58 mph / 86 mph
Typical / low: 1.7°C / 1.2°C · much of the night
In cloud: 0% 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.

The ground is likely to be very wet after recent rain. Expect boggy approaches and choose a durable pitch carefully.

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

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. Icy patches are likely on the rock, which makes it treacherous without winter kit. Gusts of 65–75 mph are strong enough to make movement extremely difficult on exposed ground. During the strongest gusts, walking or standing may be impossible and you could be blown off your feet. Avoid exposed high ground. The rock around the summit is mostly granite, a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings. 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 gust65-75 mphRain1.5 mm

Main factorsgusts of 65–75 mphwet rock likelySnow is likely to be lying on high ground, with further snowfall possible during the day

Representative rock around the summit and along available routes Biotite granite Cairngorm Pluton, Phase 2

Origin: Igneous
Broad rock-response group: Granite, gneiss or gabbro
Mapping: BGS Geology 50K · 1:50,000
Summit area: Granite, gneiss or gabbro in 100% of 17 BGS samples within 350 m
Rock-response profile: Moderate confidence

View the summit BGS record

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings. 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.

Ben Macdui and Derry Cairngorm

granite, gneiss or gabbro

Ben Macdui and Cairn Gorm

granite, gneiss or gabbro

Geological detail and BGS records

Mapped variation

3 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 Biotite granite Cairngorm Pluton, Phase 2 1,071–1,309 m samples Seen on Ben Macdui and Derry Cairngorm, Ben Macdui and Cairn Gorm

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings.

BGS record

Route sample Porphyritic granite Cairngorm Pluton, Phase 2 733–958 m samples Seen on Ben Macdui and Derry Cairngorm

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings.

BGS record

Route sample Granite Cairngorm Pluton, Phase 2 Around 1,138 m Seen on Ben Macdui and Cairn Gorm

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings.

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

Overnight · Aurora, stars & meteorsAfter darkBetaMostly cloudy, so little chance of seeing the stars. Rain at times. Moonlight washes out the fainter stars. View forecastClose forecast

After dark: aurora and stargazing

Night beginning 2026-10-24. All times are UK local time.

Stargazing

Poor sky conditions during the best available spell: 25 Oct, 01:00 BST to 01:00 GMT.

Mostly cloudy, so little chance of seeing the stars. Rain at times. Moonlight washes out the fainter stars.

A bright moon is up all through the dark hours, washing out fainter stars and meteors.

Sky conditions through the night

Fully dark periods. Conditions can change between forecast hours.
Time	Viewing conditions
24 Oct, 20:00 BST to 21:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
24 Oct, 21:00 BST to 22:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
24 Oct, 22:00 BST to 23:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
24 Oct, 23:00 BST to 25 Oct, 00:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Moonlight washes out the fainter stars. Limited model coverage.
25 Oct, 00:00 BST to 01:00 BST	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Moonlight washes out the fainter stars. Limited model coverage.
25 Oct, 01:00 GMT to 02:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Moonlight washes out the fainter stars. Limited model coverage.
25 Oct, 01:00 BST to 01:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Moonlight washes out the fainter stars. Limited model coverage.
25 Oct, 02:00 GMT to 03:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Moonlight washes out the fainter stars. Limited model coverage.
25 Oct, 03:00 GMT to 04:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
25 Oct, 04:00 GMT to 05:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.

Moon, darkness and meteor showers

Near-full moon, about 98% illuminated.

Moonset around 25 Oct, 06:10 GMT.

Full darkness: 24 Oct, 20:00 BST to 25 Oct, 05:00 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 315 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 Ben Macdui on Saturday 24 October 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

Sunday 25 October 2026Confidence: Low

Overall hill weather-28Severe hill conditions

Summit wind · 08:00-17:0045-60 mph westerly Summit gusts · 08:00-17:0070-80 mph Feels like-14 to -10°C PrecipitationUp to around 2 mm Cloud-free summit estimate90% Freezing level800-1,100 m DaylightSunrise 07:08 · Sunset 16:47 · 9.7 hours daylight

The day on the hill

A wild day on the tops of Ben Macdui, with severe winds and sleet or snow up high. Not a day for the summit.

Snow and navigation

There is a risk of blizzard conditions in the morning, when snow and strong winds coincide. Paths and footprints can quickly disappear beneath falling and blowing snow. Snow may collect in deeper drifts in hollows, behind boulders and on slopes sheltered from the wind. Exposed ground may be scoured while nearby drifts deepen. Wind-loaded slopes can also be avalanche terrain. Check the local avalanche forecast where one is available; this is not an assessment of slope stability.

Wind

On the summit expect a westerly wind of around 50–60 mph first thing, easing to 45–55 mph by mid-afternoon, with gusts of 70–80 mph at the windiest. Lower down on the open hillside it will be more like 15–25 mph. Gusts like that are strong enough to make movement extremely difficult on exposed ground. During the strongest gusts, walking or standing may be impossible and you could be blown off your feet. Avoid exposed high ground. If the windier forecast models are right, summit gusts could reach 90–100 mph.

Cloud and visibility

The tops should stay clear of cloud all day. Where snow covers the ground, the sky and hillside can merge into a featureless white view, making it difficult to judge slope or direction. Do not rely on following a visible path. Avoid exposed routes if you cannot navigate safely in these conditions, and turn back before visibility deteriorates.

Rain and ground

Snow at first, clearing by midday. Some forecast models keep it drier in the morning. It will be wet underfoot after recent rain. The forecast model suggests less than 1 cm of fresh snowfall at around 1303 m between 08:00 and 17:00 (local time). The amount settling is uncertain and will vary with melting and drifting.

Warmth and kit

On the tops it will be around -4 to 0°C, feeling like -14 to -10°C in the wind. The freezing level is around 900–1200 m, so it will be below freezing on the tops. Hat, gloves and a warm insulated layer are essential, with extra warmth for stops. Pack waterproofs too, and keep a warm layer dry in your pack.

Daylight

Sunset is around 4:45pm, 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. It's still four days off and could change, so check again nearer the time.

Below zero means severe hill conditions. More negative scores indicate more severe forecast weather. Read the hazard details before making plans. Below zero means severe hill conditions. More negative scores indicate more severe forecast weather. Read the hazard details before making plans.

Sunshine context Model-grid estimate, not summit sunshine

The surrounding model grid indicates Less than 1 hour 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: 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 Severe hill conditions Summit winds around 50-60 mph. Gusts around 70-80 mph are possible on exposed ground. Gusts this strong can make movement extremely difficult on exposed ground. During the strongest gusts, walking or standing may be impossible and you could be blown off your feet. Avoid exposed high ground. Rain is forecast during this period. Rain is possible during the morning, but forecast models disagree on whether it will fall.

-53

Afternoon · 12:00–17:00 Severe hill conditions Summit winds around 45-55 mph. Gusts around 65-75 mph are possible on exposed ground. Gusts this strong can make movement extremely difficult on exposed ground. During the strongest gusts, walking or standing may be impossible and you could be blown off your feet. Avoid exposed high ground. Rain is possible during the afternoon, but forecast models disagree on whether it will fall.

-2

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 70 mph. 0Poor · 600 m View detailsHide details

Night beginning Sunday 25 October 2026

Full overnight outlook

Not a night to camp on the open hill. Gusts reach about 70 mph around 900 m and nearer 50 mph around 300 m, strong enough to flatten or tear a tent. Don't count on finding shelter once you're up there. Choose another night or a low, sheltered spot. Dry to pitch, then some light rain overnight and into the morning, so expect to pack a wet tent. A cold night, down to about 0°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 rain1.4 mm Open ground · 600 m36 mph · gusts 60 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 0°C or lower

Moon overnight

Near-full moon

Illuminated disc: 100%
Moonrise: Outside this window
Moonset: 07:55 next morning GMT

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

Overnight window: 25 Oct, 17:00 GMT to 26 Oct, 08:00 GMT. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.

Elevation reference (open ground)

300 m9 · very poor

Wind / gust: 30 mph / 49 mph
Typical / low: 4.5°C / 3.5°C · several hours
In cloud: 0% of modelled night
Condensation: Low

600 m0 · very poor

Wind / gust: 36 mph / 60 mph
Typical / low: 3.2°C / 2.4°C · much of the night
In cloud: 0% of modelled night
Condensation: Low

900 m0 · very poor

Wind / gust: 42 mph / 70 mph
Typical / low: 1.5°C / 0.4°C · much of the night
In cloud: 0% 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

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. Icy patches are likely on the rock, which makes it treacherous without winter kit. Gusts of 70–80 mph are strong enough to make movement extremely difficult on exposed ground. During the strongest gusts, walking or standing may be impossible and you could be blown off your feet. Avoid exposed high ground. The rock around the summit is mostly granite, a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings. 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 gust70-80 mphRain0.8 mm

Main factorsgusts of 70–80 mphwet rock likelySnow is likely to be lying on high ground, with further snowfall possible during the day

Representative rock around the summit and along available routes Biotite granite Cairngorm Pluton, Phase 2

Origin: Igneous
Broad rock-response group: Granite, gneiss or gabbro
Mapping: BGS Geology 50K · 1:50,000
Summit area: Granite, gneiss or gabbro in 100% of 17 BGS samples within 350 m
Rock-response profile: Moderate confidence

View the summit BGS record

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings. 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.

Ben Macdui and Derry Cairngorm

granite, gneiss or gabbro

Ben Macdui and Cairn Gorm

granite, gneiss or gabbro

Geological detail and BGS records

Mapped variation

3 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 Biotite granite Cairngorm Pluton, Phase 2 1,071–1,309 m samples Seen on Ben Macdui and Derry Cairngorm, Ben Macdui and Cairn Gorm

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings.

BGS record

Route sample Porphyritic granite Cairngorm Pluton, Phase 2 733–958 m samples Seen on Ben Macdui and Derry Cairngorm

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings.

BGS record

Route sample Granite Cairngorm Pluton, Phase 2 Around 1,138 m Seen on Ben Macdui and Cairn Gorm

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings.

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

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

After dark: aurora and stargazing

Night beginning 2026-10-25. 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: 25 Oct, 19:00 GMT to 20:00 GMT.

Mostly cloudy, so little chance of seeing the stars. Moonlight washes out the fainter stars.

A bright moon is up all through the dark hours, washing out fainter stars and meteors.

Sky conditions through the night

Fully dark periods. Conditions can change between forecast hours.
Time	Viewing conditions
25 Oct, 18:55 GMT to 19:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Moonlight washes out the fainter stars. Limited model coverage.
25 Oct, 19:00 GMT to 20:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Moonlight washes out the fainter stars. Limited model coverage.
25 Oct, 20:00 GMT to 21:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
25 Oct, 21:00 GMT to 22:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
25 Oct, 22:00 GMT to 23:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
25 Oct, 23:00 GMT to 26 Oct, 00:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
26 Oct, 00:00 GMT to 01:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
26 Oct, 01:00 GMT to 02:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
26 Oct, 02:00 GMT to 03:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
26 Oct, 03:00 GMT to 04:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
26 Oct, 04:00 GMT to 05:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
26 Oct, 05:00 GMT to 05:05 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.

Moon, darkness and meteor showers

Near-full moon, about 100% illuminated.

Moonset around 26 Oct, 07:40 GMT.

Full darkness: 25 Oct, 18:55 GMT to 26 Oct, 05:05 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 315 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 Ben Macdui on Sunday 25 October 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

Monday 26 October 2026Confidence: Unavailable

Overall hill weather-2Severe hill conditions

Summit wind · 08:00-17:0045-55 mph westerly Summit gusts · 08:00-17:0065-75 mph Feels like-8 to -4°C PrecipitationUp to around 2 mm Cloud-free summit estimate45% Cloud base through day1,200-1,900 m Freezing levelAbove summit DaylightSunrise 07:11 · Sunset 16:45 · 9.6 hours daylight

The day on the hill

A wild day on the tops of Ben Macdui, with severe winds and cloud on the tops early. Not a day for the summit.

Wind

On the summit expect a westerly wind of 45–55 mph for most of the day, with gusts of 65–75 mph at the windiest. Lower down on the open hillside it will be more like 15–25 mph. Gusts like that are strong enough to make movement extremely difficult on exposed ground. During the strongest gusts, walking or standing may be impossible and you could be blown off your feet. Avoid exposed high ground. If the windier forecast models are right, summit gusts could reach 90–100 mph.

Cloud and visibility

Cloud on the tops early should lift off them by mid-morning. The cloud base could be as low as 1100–1400 m early in the morning. A few forecast models bring it lower still, to around 700–1000 m.

Rain and ground

Drizzle for much of the day. Some forecast models keep it drier in the morning. It will be wet underfoot after recent rain.

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 4:45pm, 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.

Below zero means severe hill conditions. More negative scores indicate more severe forecast weather. Read the hazard details before making plans. Below zero means severe hill conditions. More negative scores indicate more severe forecast weather. Read the hazard details before making plans.

Sunshine context Model-grid estimate, not summit sunshine

The surrounding model grid indicates 1.3 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: 0.8 h
Later: 0 h

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

Morning · 08:00–12:00 Severe hill conditions Summit winds around 45-55 mph. Gusts around 65-75 mph are possible on exposed ground. Gusts this strong can make movement extremely difficult on exposed ground. During the strongest gusts, walking or standing may be impossible and you could be blown off your feet. Avoid exposed high ground. Summit cloud is more persistent early in this period, with better prospects later. Rain is forecast during this period. Some forecast models bring rain during the morning, while others keep it mostly dry.

-15

Afternoon · 12:00–17:00 Poor Summit winds around 45-55 mph. Gusts around 65-75 mph are possible on exposed ground. Gusts this strong can make walking very difficult and tiring, with a risk of being blown off your feet. Avoid exposed ridges and edges. Rain is forecast during this period.

10

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 65 mph. 9Poor · 600 m View detailsHide details

Night beginning Monday 26 October 2026

Full overnight outlook

Not a night to camp on the open hill. Gusts reach about 65 mph around 900 m and nearer 45 mph around 300 m, strong enough to flatten or tear a tent. Don't count on finding shelter once you're up there. Choose another night or a low, sheltered spot. Dry to pitch, then some light rain overnight and into the morning, so expect to pack a wet tent. 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. A cold night, down to about 3°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 rain2.7 mm Open ground · 600 m34 mph · gusts 54 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 2°C or lower

Moon overnight

Near-full moon

Illuminated disc: 99%
Moonrise: Outside this window
Moonset: Outside this window

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

Overnight window: 26 Oct, 17:00 GMT to 27 Oct, 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: 28 mph / 45 mph
Typical / low: 8.2°C / 4.8°C · a brief spell
In cloud: 0% of modelled night
Condensation: Moderate

600 m9 · very poor

Wind / gust: 34 mph / 54 mph
Typical / low: 7.1°C / 4.8°C · a brief spell
In cloud: 0% of modelled night
Condensation: Moderate

900 m0 · very poor

Wind / gust: 40 mph / 64 mph
Typical / low: 6.0°C / 2.6°C · a brief spell
In cloud: 53% 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

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. Snow is likely on the rock and ledges, so it becomes a winter route. Gusts of 65–75 mph are strong enough to make movement extremely difficult on exposed ground. During the strongest gusts, walking or standing may be impossible and you could be blown off your feet. Avoid exposed high ground. Cloud on the tops may make route-finding and retreat harder. The rock around the summit is mostly granite, a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings. 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 gust65-75 mphRain1.0 mm

Main factorsgusts of 65–75 mphwet rock likelySnow is likely to be lying on high ground. Scrambling may require winter mountaineering skills and equipment

Representative rock around the summit and along available routes Biotite granite Cairngorm Pluton, Phase 2

Origin: Igneous
Broad rock-response group: Granite, gneiss or gabbro
Mapping: BGS Geology 50K · 1:50,000
Summit area: Granite, gneiss or gabbro in 100% of 17 BGS samples within 350 m
Rock-response profile: Moderate confidence

View the summit BGS record

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings. 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.

Ben Macdui and Derry Cairngorm

granite, gneiss or gabbro

Ben Macdui and Cairn Gorm

granite, gneiss or gabbro

Geological detail and BGS records

Mapped variation

3 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 Biotite granite Cairngorm Pluton, Phase 2 1,071–1,309 m samples Seen on Ben Macdui and Derry Cairngorm, Ben Macdui and Cairn Gorm

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings.

BGS record

Route sample Porphyritic granite Cairngorm Pluton, Phase 2 733–958 m samples Seen on Ben Macdui and Derry Cairngorm

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings.

BGS record

Route sample Granite Cairngorm Pluton, Phase 2 Around 1,138 m Seen on Ben Macdui and Cairn Gorm

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings.

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

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

After dark: aurora and stargazing

Night beginning 2026-10-26. 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: 26 Oct, 19:00 GMT to 20:00 GMT.

Mostly cloudy, so little chance of seeing the stars. Moonlight washes out the fainter stars.

A bright moon is up all through the dark hours, washing out fainter stars and meteors.

Sky conditions through the night

Fully dark periods. Conditions can change between forecast hours.
Time	Viewing conditions
26 Oct, 18:55 GMT to 19:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Moonlight washes out the fainter stars. Limited model coverage.
26 Oct, 19:00 GMT to 20:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Moonlight washes out the fainter stars. Limited model coverage.
26 Oct, 20:00 GMT to 21:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Moonlight washes out the fainter stars. Limited model coverage.
26 Oct, 21:00 GMT to 22:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Moonlight washes out the fainter stars. Limited model coverage.
26 Oct, 22:00 GMT to 23:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Moonlight washes out the fainter stars. Limited model coverage.
26 Oct, 23:00 GMT to 27 Oct, 00:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Moonlight washes out the fainter stars. Limited model coverage.
27 Oct, 00:00 GMT to 01:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Moonlight washes out the fainter stars. Limited model coverage.
27 Oct, 01:00 GMT to 02:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
27 Oct, 02:00 GMT to 03:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
27 Oct, 03:00 GMT to 04:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
27 Oct, 04:00 GMT to 05:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
27 Oct, 05:00 GMT to 05:05 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.

Moon, darkness and meteor showers

Near-full moon, about 99% illuminated.

Full darkness: 26 Oct, 18:55 GMT to 27 Oct, 05:05 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 315 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 Ben Macdui on Monday 26 October 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

Tuesday 27 October 2026Confidence: Unavailable

Overall hill weather26Poor

Summit wind · 08:00-17:0035-50 mph southwesterly Summit gusts · 08:00-17:0055-65 mph Feels like-8 to -4°C PrecipitationAround 2-5 mm Cloud-free summit estimate90% Cloud base through day1,400-1,700 m Freezing levelAbove summit DaylightSunrise 07:13 · Sunset 16:42 · 9.5 hours daylight

The day on the hill

A poor day on the tops of Ben Macdui, with very strong, gusty winds and drizzle for much of the day.

Wind

On the summit expect a south-westerly wind of 35–50 mph for most of the day, with gusts of 55–65 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 very difficult and tiring, with a risk of being blown off your feet. Avoid exposed ridges and edges. If the windier forecast models are right, summit gusts could reach 80–90 mph.

Cloud and visibility

The tops should stay clear of cloud all day.

Rain and ground

Drizzle for much of the day, turning lighter later. Expect 2–5 mm in total.

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

Sunset is around 4:40pm, 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 8.2 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: 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 Poor Summit winds around 40-50 mph. Gusts around 55-65 mph are possible on exposed ground. Gusts this strong can make walking very difficult and tiring, with a risk of being blown off your feet. Avoid exposed ridges and edges. Rain is forecast during this period.

17

Afternoon · 12:00–17:00 Poor Rain eases compared with the morning. Summit winds around 35-45 mph. Gusts around 50-60 mph are possible on exposed ground. Gusts this strong can make walking very difficult and tiring, with a risk of being blown off your feet. Avoid exposed ridges and edges. Rain is forecast during this period.

36

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. 9Poor · 600 m View detailsHide details

Night beginning Tuesday 27 October 2026

Full overnight outlook

Not a night to camp on the open hill. Gusts reach about 55 mph around 900 m and nearer 40 mph around 300 m, strong enough to flatten or tear a tent. Don't count on finding shelter once you're up there. Choose another night or a low, sheltered spot. Expect some light rain, with rain while you pitch and still falling when you pack up. 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 rain1.5 mm Open ground · 600 m30 mph · gusts 49 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 0°C or lower

Moon overnight

Waning gibbous moon

Illuminated disc: 95%
Moonrise: Outside this window
Moonset: Outside this window

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

Overnight window: 27 Oct, 17:00 GMT to 28 Oct, 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: 25 mph / 40 mph
Typical / low: 5.3°C / 3.9°C · several hours
In cloud: 0% of modelled night
Condensation: Moderate

600 m9 · very poor

Wind / gust: 30 mph / 49 mph
Typical / low: 5.3°C / 3.9°C · several hours
In cloud: 0% of modelled night
Condensation: Moderate

900 m9 · very poor

Wind / gust: 36 mph / 57 mph
Typical / low: 3.3°C / 2.2°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

Daytime · exposed rockClimbing & scramblingBetaVery poor conditions for exposed scrambling: gusts of 55–65 mph. 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 55–65 mph are strong enough to make walking very difficult and tiring, with a risk of being blown off your feet. Avoid exposed ridges and edges. The rock around the summit is mostly granite, a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings. 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 gust55-65 mphRain3.5 mm

Main factorsgusts of 55–65 mphwet rock likely

Representative rock around the summit and along available routes Biotite granite Cairngorm Pluton, Phase 2

Origin: Igneous
Broad rock-response group: Granite, gneiss or gabbro
Mapping: BGS Geology 50K · 1:50,000
Summit area: Granite, gneiss or gabbro in 100% of 17 BGS samples within 350 m
Rock-response profile: Moderate confidence

View the summit BGS record

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings. 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.

Ben Macdui and Derry Cairngorm

granite, gneiss or gabbro

Ben Macdui and Cairn Gorm

granite, gneiss or gabbro

Geological detail and BGS records

Mapped variation

3 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 Biotite granite Cairngorm Pluton, Phase 2 1,071–1,309 m samples Seen on Ben Macdui and Derry Cairngorm, Ben Macdui and Cairn Gorm

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings.

BGS record

Route sample Porphyritic granite Cairngorm Pluton, Phase 2 733–958 m samples Seen on Ben Macdui and Derry Cairngorm

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings.

BGS record

Route sample Granite Cairngorm Pluton, Phase 2 Around 1,138 m Seen on Ben Macdui and Cairn Gorm

Granite is a coarse, crystalline rock. It has excellent friction when dry and clean and is fair when wet, but greasy where there is lichen or moss. It is generally solid, but weathers into rounded slabs and blocks, and loose granite grit on slabs can roll underfoot like ball bearings.

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

Overnight · Aurora, stars & meteorsAfter darkBetaMostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. View forecastClose forecast

After dark: aurora and stargazing

Night beginning 2026-10-27. 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: 27 Oct, 19:00 GMT to 20:00 GMT.

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

A bright moon is up all through the dark hours, washing out fainter stars and meteors.

Sky conditions through the night

Fully dark periods. Conditions can change between forecast hours.
Time	Viewing conditions
27 Oct, 18:50 GMT to 19:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Moonlight washes out the fainter stars. Limited model coverage.
27 Oct, 19:00 GMT to 20:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
27 Oct, 20:00 GMT to 21:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
27 Oct, 21:00 GMT to 22:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
27 Oct, 22:00 GMT to 23:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
27 Oct, 23:00 GMT to 28 Oct, 00:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
28 Oct, 00:00 GMT to 01:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
28 Oct, 01:00 GMT to 02:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
28 Oct, 02:00 GMT to 03:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
28 Oct, 03:00 GMT to 04:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
28 Oct, 04:00 GMT to 05:00 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.
28 Oct, 05:00 GMT to 05:05 GMT	Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. Hazy, which dims the fainter stars. Moonlight washes out the fainter stars. Limited model coverage.

Moon, darkness and meteor showers

Near-full moon, about 96% illuminated.

Full darkness: 27 Oct, 18:50 GMT to 28 Oct, 05:05 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 315 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 Ben Macdui on Tuesday 27 October 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

Ben Macdui (Beinn Macduibh) weather forecast.

See the wind across Ben Macdui.

Choose your hill day.

The day on the hill

Wind

Cloud and visibility

Rain and ground

Warmth and kit

Daylight

Full overnight outlook

Moon overnight

Elevation reference (open ground)

Full climbing & scrambling outlook

Rock groups along the sampled routes

Ben Macdui and Derry Cairngorm

Ben Macdui and Cairn Gorm

3 rock types appear in the mapped samples

After dark: aurora and stargazing

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

Stargazing

Darkness of the surroundings

The day on the hill

Wind

Cloud and visibility

Rain and ground

Warmth and kit

Daylight

Forecast confidence

Full overnight outlook

Moon overnight

Elevation reference (open ground)

Full climbing & scrambling outlook

Rock groups along the sampled routes

Ben Macdui and Derry Cairngorm

Ben Macdui and Cairn Gorm

3 rock types appear in the mapped samples

After dark: aurora and stargazing

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

Stargazing

Darkness of the surroundings

The day on the hill

Things to watch

Snow and navigation

Wind

Cloud and visibility

Rain and ground

Warmth and kit

Daylight

Forecast confidence

Full overnight outlook

Moon overnight

Elevation reference (open ground)

Full climbing & scrambling outlook

Rock groups along the sampled routes

Ben Macdui and Derry Cairngorm

Ben Macdui and Cairn Gorm

3 rock types appear in the mapped samples

After dark: aurora and stargazing

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

Stargazing

Darkness of the surroundings

The day on the hill

Snow and navigation

Wind

Cloud and visibility

Rain and ground

Warmth and kit

Daylight

Forecast confidence

Full overnight outlook

Moon overnight

Elevation reference (open ground)

Full climbing & scrambling outlook

Rock groups along the sampled routes

Ben Macdui and Derry Cairngorm

Ben Macdui and Cairn Gorm

3 rock types appear in the mapped samples

After dark: aurora and stargazing

Stargazing

Darkness of the surroundings