A poor day on the tops of Cairn Gorm, with the summit in cloud for most of the day and rain clearing by mid-afternoon.
Wind
On the summit expect a south-westerly wind of 5–20 mph for most of the day, with gusts of 20–30 mph at the windiest. The wind turns south-westerly around midday. Lower down on the open hillside the wind will be light, under 10 mph.
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 in the early afternoon. In cloud you'll be finding your way without landmarks, so carry navigation you trust and know how to use, with a backup such as a spare battery or a map and compass.
Rain and ground
Rain at first, clearing by mid-afternoon. Expect 5–10 mm in total.
Warmth and kit
On the tops it will be around 0 to 4°C, feeling like -6 to -2°C in the wind. The freezing level is above the summits. Take a hat, gloves, a windproof and a spare warm layer. Pack waterproofs too, and keep a warm layer dry in your pack.
Daylight
Sunset is around 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. Things could still change through the day, so keep an eye on the sky.
Sunshine context Model-grid estimate, not summit sunshine
The surrounding model grid indicates 0 h of sunshine. This is not a forecast of time in sunshine on the summit. Use the cloud and views outlook above for the conditions on this mountain.
Morning · 08:00–12:00
PoorSummit winds around 5-20 mph. Gusts around 20-30 mph are possible on exposed ground. Rain is forecast during this period.
22
Afternoon · 12:00–17:00
PoorSummit winds around 5-15 mph. Gusts around 15-25 mph are possible on exposed ground. Summit cloud becomes more persistent later. Rain is forecast during this period.
38
Compare an early start with later conditions. The main forecast above covers the day in more detail.
Overnight · 17:00–08:00Wild campingBetaToo windy for an exposed pitch above about 600 m (gusts of about 50 mph and about 4 mm of rain). Lower down, a poor night to camp on open ground.19Poor · 600 mView detailsHide details
Night beginning Wednesday 21 October 2026
Full overnight outlook
Too windy for an exposed pitch above about 600 m. Lower down, a poor night to camp on open ground. Gusts reach about 50 mph around 900 m and nearer 35 mph around 300 m, enough to damage a tent on open ground. Pitch low down and in real shelter, or leave it for another night. The wind swings from westerly to northwesterly overnight, so a pitch sheltered at dusk may not be by morning. Expect about 4 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 frost up around 900 m, down to about -1°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.
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 m39 · poor
Wind / gust
16 mph / 34 mph
Typical / low
4.1°C / 2.5°C · much of the night
In cloud
0% of modelled night
Condensation
High
600 m19 · very poor
Wind / gust
20 mph / 40 mph
Typical / low
2.8°C / 1.3°C · much of the night
In cloud
87% of modelled night
Condensation
High
900 m9 · very poor
Wind / gust
23 mph / 48 mph
Typical / low
0.9°C / -0.6°C · much of the night
In cloud
87% of modelled night
Condensation
High
Warmth planning: As a broad starting point, consider a warm 3-season or 3–4 season bag with an ISO/EN comfort rating at or below about -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.
Very poor conditions for exposed scrambling. The rock is likely to be wet and slippery through the day. 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 surfaceWet rock likelyPeak gust20-30 mphRain7.7 mm
Main factorswet rock likelymuch of the route may be in cloud
Representative rock around the summit and along available routes
Biotite graniteCairngorm 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
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.
Cairn Gorm
granite, gneiss or gabbro
Cairn Gorm
granite, gneiss or gabbro
Ben Macdui and Cairn Gorm
granite, gneiss or gabbro
Geological detail and BGS records
Mapped variation
2 rock types appear in the mapped samples
Samples around the summit inform the main rock-response profile, with the summit pin shown separately where it differs. Route samples add further context, but this is not a continuous geological survey.
Summit-area sample
Biotite graniteCairngorm Pluton, Phase 2625–1,242 m samplesSeen on Cairn Gorm, Cairn Gorm, 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
GraniteCairngorm Pluton, Phase 2Around 1,138 mSeen 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.
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 darkBetaNo sky forecast for this night yet. Moon and darkness times are shown separately.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
No sky forecast for this night yet. Moon and darkness times are shown separately.
Moon-free dark sky: 22 Oct, 02:50 BST to 05:55 BST.
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 353 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.
Terrain at this viewpoint
Approximate terrain horizon at Cairn Gorm. Trees, buildings and nearby obstacles are not included.
Approximate bare-earth horizon, not surveyed sightlines. Narrow ridges may fall between samples. Trees, buildings and very close obstacles are not resolved. Valid only at the named summit coordinate, not on its slopes or at a lower campsite.
Mapzen Terrain Tiles. Europe terrain produced using Copernicus data and information funded by the European Union, EU-DEM layers. UK terrain: Environment Agency copyright and/or database right 2015. Global terrain: USGS and NOAA.
Contains Welsh Government public sector information licensed under the Open Government Licence v3.0.
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.
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 Cairn Gorm on Wednesday 21 October 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Summit wind · 08:00-17:0020-40 mph westerlySummit gusts · 08:00-17:0045-55 mphFeels like-14 to -10°CPrecipitationLittle or noneCloud-free summit estimate25%Cloud base through day400-1,700 mFreezing level700-1,000 mDaylightSunrise 08:02 · Sunset 17:54 · 9.9 hours daylight
The day on the hill
A poor day on the tops of Cairn Gorm, with strong, gusty winds and a bitter wind chill.
Wind
On the summit expect a westerly wind of around 30–40 mph first thing, easing to 20–30 mph by mid-afternoon, with gusts of 45–55 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 knock you off balance, so take care near edges and on narrow ridges. If the windier forecast models are right, summit gusts could reach 55–65 mph.
Cloud and visibility
The tops are likely to drift in and out of cloud, with the best chance of a clear summit mid-afternoon. 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. Any sunshine is more likely on lower ground than on the summit.
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 -14 to -10°C in the wind. The freezing level is around 800–1100 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 4.2 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.
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.
Morning · 08:00–12:00
PoorSummit winds around 30-40 mph. Gusts around 45-55 mph are possible on exposed ground. Gusts this strong can knock you off balance, so take care near edges and on narrow ridges.
16
Afternoon · 12:00–17:00
PoorSummit winds around 20-35 mph. Gusts around 40-50 mph are possible on exposed ground. Gusts this strong can knock you off balance, so take care near edges and on narrow ridges. Summit cloud is more persistent early in this period, with better prospects later.
36
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 and about 3 mm of rain.41Poor · 600 mView 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, which makes for a noisy, testing night even in a good tent. 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 about 3 mm of rain by morning, so you'll likely pack up in the wet. Above about 600 m you'd likely be in cloud for part of the night: damp, and hard to find your way if you need to move. 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.
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: 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 m51 · mixed
Wind / gust
13 mph / 26 mph
Typical / low
4.6°C / 4.0°C · much of the night
In cloud
0% of modelled night
Condensation
High
600 m41 · mixed
Wind / gust
15 mph / 31 mph
Typical / low
3.6°C / 2.8°C · much of the night
In cloud
87% of modelled night
Condensation
High
900 m30 · poor
Wind / gust
18 mph / 36 mph
Typical / low
1.6°C / 0.9°C · much of the night
In cloud
87% of modelled night
Condensation
High
Warmth planning: As a broad starting point, consider a warm 3-season or 3–4 season bag with an ISO/EN comfort rating at or below about 0°C. Allow more margin if you sleep cold or expect fatigue, and use an adequate insulated mat. Dampness is possible, so keep the sleep system dry and ensure its insulation remains effective if damp.
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 45–55 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 surfaceDry overhead; seepage uncertainPeak gust45-55 mphRainPossible · 82%
Main factorsgusts of 45–55 mphdamp or incompletely dried rock possiblemuch of the route may be in cloud
Representative rock around the summit and along available routes
Biotite graniteCairngorm 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
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.
Cairn Gorm
granite, gneiss or gabbro
Cairn Gorm
granite, gneiss or gabbro
Ben Macdui and Cairn Gorm
granite, gneiss or gabbro
Geological detail and BGS records
Mapped variation
2 rock types appear in the mapped samples
Samples around the summit inform the main rock-response profile, with the summit pin shown separately where it differs. Route samples add further context, but this is not a continuous geological survey.
Summit-area sample
Biotite graniteCairngorm Pluton, Phase 2625–1,242 m samplesSeen on Cairn Gorm, Cairn Gorm, 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
GraniteCairngorm Pluton, Phase 2Around 1,138 mSeen 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.
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 darkBetaNo sky forecast for this night yet. Moon and darkness times are shown separately.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
No sky forecast for this night yet. Moon and darkness times are shown separately.
Moon-free dark sky: 23 Oct, 04:15 BST to 05:55 BST.
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 353 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.
Terrain at this viewpoint
Approximate terrain horizon at Cairn Gorm. Trees, buildings and nearby obstacles are not included.
Approximate bare-earth horizon, not surveyed sightlines. Narrow ridges may fall between samples. Trees, buildings and very close obstacles are not resolved. Valid only at the named summit coordinate, not on its slopes or at a lower campsite.
Mapzen Terrain Tiles. Europe terrain produced using Copernicus data and information funded by the European Union, EU-DEM layers. UK terrain: Environment Agency copyright and/or database right 2015. Global terrain: USGS and NOAA.
Contains Welsh Government public sector information licensed under the Open Government Licence v3.0.
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.
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 Cairn Gorm on Thursday 22 October 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Serious conditions on Cairn Gorm, 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 a north-easterly wind of around 25–35 mph first thing, easing to 10–20 mph by mid-afternoon, with gusts of 35–45 mph at the windiest. The wind turns northerly in the early afternoon. 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 50–60 mph. It gets windier still after dark, with summit gusts of 50–60 mph, so bear that in mind if you will be out late.
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 in the early afternoon. In cloud you'll be finding your way without landmarks, so carry navigation you trust and know how to use, with a backup such as a spare battery or a map and compass. 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, turning lighter later. 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 -4 to 0°C, feeling like -12 to -8°C in the wind. The freezing level falls through the day, to around 700–1000 m by mid-afternoon. 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 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.
Morning · 08:00–12:00
Severe hill conditionsSummit winds around 20-30 mph. Gusts around 35-45 mph are possible on exposed ground. Gusts this strong can make walking into it hard work, with buffeting on ridges and edges. Rain is forecast during this period. Rain is forecast during the morning, but models differ considerably on the amount.
-32
Afternoon · 12:00–17:00
PoorWinds ease compared with the morning. Summit winds around 5-20 mph. Gusts around 20-30 mph are possible on exposed ground. Rain is forecast during this period.
12
Compare an early start with later conditions. The main forecast above covers the day in more detail.
Overnight · 17:00–08:00Wild campingBetaToo windy for an exposed pitch above about 600 m (gusts of about 55 mph and about 4 mm of rain). Lower down, a poor night to camp on open ground.9Poor · 600 mView detailsHide details
Night beginning Friday 23 October 2026
Full overnight outlook
Too windy for an exposed pitch above about 600 m. Lower down, a poor night to camp on open ground. Gusts reach about 55 mph around 900 m and nearer 40 mph around 300 m, strong enough to flatten or tear a tent. Pitch low down and in real shelter, or leave it for another night. The wind swings from northwesterly to westerly overnight, so a pitch sheltered at dusk may not be by morning. Expect about 4 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 frost up around 900 m, down to about -1°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.
Extensive cloud may limit moonlight. 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
20 mph / 39 mph
Typical / low
3.1°C / 2.0°C · much of the night
In cloud
0% of modelled night
Condensation
Moderate
600 m9 · very poor
Wind / gust
24 mph / 47 mph
Typical / low
1.8°C / 0.8°C · much of the night
In cloud
27% of modelled night
Condensation
Moderate
900 m9 · very poor
Wind / gust
29 mph / 55 mph
Typical / low
-0.1°C / -1.1°C · much of the night
In cloud
33% 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.
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 35–45 mph could throw you off balance on exposed moves and ridges. Cloud on the tops may make route-finding and retreat harder. The rock around the summit is mostly 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 gust35-45 mphRain25.2 mm
Main factorsgusts of 35–45 mphwet rock likelymuch of the route may be in cloud
Representative rock around the summit and along available routes
Biotite graniteCairngorm 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
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.
Cairn Gorm
granite, gneiss or gabbro
Cairn Gorm
granite, gneiss or gabbro
Ben Macdui and Cairn Gorm
granite, gneiss or gabbro
Geological detail and BGS records
Mapped variation
2 rock types appear in the mapped samples
Samples around the summit inform the main rock-response profile, with the summit pin shown separately where it differs. Route samples add further context, but this is not a continuous geological survey.
Summit-area sample
Biotite graniteCairngorm Pluton, Phase 2625–1,242 m samplesSeen on Cairn Gorm, Cairn Gorm, 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
GraniteCairngorm Pluton, Phase 2Around 1,138 mSeen 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.
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 darkBetaNo sky forecast for this night yet. Moon and darkness times are shown separately.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
No sky forecast for this night yet. Moon and darkness times are shown separately.
Moon-free dark sky: 24 Oct, 05:40 BST to 06:00 BST.
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 353 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.
Terrain at this viewpoint
Approximate terrain horizon at Cairn Gorm. Trees, buildings and nearby obstacles are not included.
Approximate bare-earth horizon, not surveyed sightlines. Narrow ridges may fall between samples. Trees, buildings and very close obstacles are not resolved. Valid only at the named summit coordinate, not on its slopes or at a lower campsite.
Mapzen Terrain Tiles. Europe terrain produced using Copernicus data and information funded by the European Union, EU-DEM layers. UK terrain: Environment Agency copyright and/or database right 2015. Global terrain: USGS and NOAA.
Contains Welsh Government public sector information licensed under the Open Government Licence v3.0.
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.
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 Cairn Gorm on Friday 23 October 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
A wild day on the tops of Cairn Gorm, with severe winds and sleet or snow up high. Not a day for the summit.
Things to watch
Burns could rise quickly through the day and overnight. Timings are rough. Turn back if a crossing looks unsafe.
Snow and navigation
There is a risk of blizzard conditions during the morning and 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 15–25 mph first thing, rising to 50–60 mph by early afternoon, with gusts of 65–75 mph at the windiest. Lower down on the open hillside it will be more like 15–30 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 80–90 mph.
Cloud and visibility
The tops are likely to drift in and out of cloud, with the best chance of a clear summit early in the morning. The cloud base could be as low as 200–500 m in the early afternoon. In cloud you'll be finding your way without landmarks, so carry navigation you trust and know how to use, with a backup such as a spare battery or a map and compass. Visibility may drop briefly in showers. Mist or fog is possible in the valleys through the morning. 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
A band of sleet and snow moves in mid-morning, heavy at times. Expect 10–20 mm in total, measured as melted water, so any snow would lie deeper. Some forecast models keep it drier in the morning. 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. 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.
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.
Morning · 08:00–12:00
PoorSummit winds around 10-20 mph early in the morning, strengthening to 25-35 mph later. Gusts around 35-45 mph are possible on exposed ground. Gusts this strong can make walking into it hard work, with buffeting on ridges and edges. Summit cloud becomes more persistent later. Rain is forecast during this period. Rain is possible during the morning, but forecast models disagree on whether it will fall.
43
Afternoon · 12:00–17:00
Severe hill conditionsWinds strengthen compared with the morning. More rain is expected. Summit winds around 35-55 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 forecast during this period. Some forecast models bring rain during the afternoon, while others keep it mostly dry.
-52
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 around 14 mm of rain.0Poor · 600 mView 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 northwesterly overnight, so a pitch sheltered at dusk may not be by morning. Expect a wet night, around 14 mm of rain, with rain while you pitch and still falling when you pack up. At every height we checked (300-900 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 frost up around 900 m, down to about -1°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. The ground will be sodden after recent rain, so pick a firm, well-drained pitch.
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 / 60 mph
Typical / low
4.7°C / 2.8°C · much of the night
In cloud
31% of modelled night
Condensation
High
600 m0 · very poor
Wind / gust
50 mph / 73 mph
Typical / low
2.8°C / 0.9°C · much of the night
In cloud
31% of modelled night
Condensation
High
900 m0 · very poor
Wind / gust
59 mph / 85 mph
Typical / low
0.8°C / -1.1°C · much of the night
In cloud
44% 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.
The ground is likely to be very wet after recent rain. Expect boggy approaches and choose a durable pitch carefully.
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. 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 mphRain12.9 mm
Main factorsgusts of 65–75 mphwet rock likelymuch of the route may be in cloud
Representative rock around the summit and along available routes
Biotite graniteCairngorm 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
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.
Cairn Gorm
granite, gneiss or gabbro
Cairn Gorm
granite, gneiss or gabbro
Ben Macdui and Cairn Gorm
granite, gneiss or gabbro
Geological detail and BGS records
Mapped variation
2 rock types appear in the mapped samples
Samples around the summit inform the main rock-response profile, with the summit pin shown separately where it differs. Route samples add further context, but this is not a continuous geological survey.
Summit-area sample
Biotite graniteCairngorm Pluton, Phase 2625–1,242 m samplesSeen on Cairn Gorm, Cairn Gorm, 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
GraniteCairngorm Pluton, Phase 2Around 1,138 mSeen 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.
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 darkBetaNo sky forecast for this night yet. Moon and darkness times are shown separately.View forecastClose forecast
After dark: aurora and stargazing
Night beginning 2026-10-24. All times are UK local time.
Stargazing
No sky forecast for this night yet. Moon and darkness times are shown separately.
A bright moon is up all through the dark hours, washing out fainter stars and meteors.
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 353 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.
Terrain at this viewpoint
Approximate terrain horizon at Cairn Gorm. Trees, buildings and nearby obstacles are not included.
Approximate bare-earth horizon, not surveyed sightlines. Narrow ridges may fall between samples. Trees, buildings and very close obstacles are not resolved. Valid only at the named summit coordinate, not on its slopes or at a lower campsite.
Mapzen Terrain Tiles. Europe terrain produced using Copernicus data and information funded by the European Union, EU-DEM layers. UK terrain: Environment Agency copyright and/or database right 2015. Global terrain: USGS and NOAA.
Contains Welsh Government public sector information licensed under the Open Government Licence v3.0.
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.
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 Cairn Gorm on Saturday 24 October 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
A wild day on the tops of Cairn Gorm, with severe winds and sleet or snow up high. Not a day for the summit.
Things to watch
Burns could rise quickly through much of the day and into the evening. Timings are rough. Turn back if a crossing looks unsafe.
Snow and navigation
There is a risk of blizzard conditions during the morning and 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 north-westerly wind of 55–70 mph for most of the day, with gusts of 80–90 mph at the windiest. Lower down on the open hillside it will be more like 20–30 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.
Cloud and visibility
Expect the summit to be in cloud for most of the day. The cloud base could be as low as 100–400 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. Any sunshine is more likely on lower ground than on the summit. 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. Expect 10–20 mm in total, measured as melted water, so any snow would lie deeper. 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 -4 to 0°C, feeling like -16 to -12°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 7.8 h of sunshine. This is not a forecast of time in sunshine on the summit. Use the cloud and views outlook above for the conditions on this mountain.
Cloud may obscure this summit even while the surrounding model grid indicates sunshine. The low cloud-free summit estimate is a reason to be cautious about expecting views.
Morning · 08:00–12:00
Severe hill conditionsSummit winds around 60-70 mph. Gusts around 80-90 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.
-133
Afternoon · 12:00–17:00
Severe hill conditionsSummit winds around 55-65 mph. Gusts around 80-90 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 afternoon, but forecast models disagree on whether it will fall.
-130
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 75 mph.0Poor · 600 mView detailsHide details
Night beginning Sunday 25 October 2026
Full overnight outlook
Not a night to camp on the open hill. Gusts reach about 75 mph around 900 m and nearer 55 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 northwesterly to westerly overnight, so a pitch sheltered at dusk may not be by morning. Expect a little rain, mostly early on, so you'll likely pitch in the rain. 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.
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
24 mph / 54 mph
Typical / low
3.8°C / 3.1°C · much of the night
In cloud
0% of modelled night
Condensation
Moderate
600 m0 · very poor
Wind / gust
28 mph / 65 mph
Typical / low
2.8°C / 2.2°C · much of the night
In cloud
0% of modelled night
Condensation
Moderate
900 m0 · very poor
Wind / gust
33 mph / 77 mph
Typical / low
0.9°C / 0.2°C · much of the night
In cloud
20% 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.
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 80–90 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 gust80-90 mphRain10.7 mm
Main factorsgusts of 80–90 mphwet rock likelymuch of the route may be in cloud
Representative rock around the summit and along available routes
Biotite graniteCairngorm 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
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.
Cairn Gorm
granite, gneiss or gabbro
Cairn Gorm
granite, gneiss or gabbro
Ben Macdui and Cairn Gorm
granite, gneiss or gabbro
Geological detail and BGS records
Mapped variation
2 rock types appear in the mapped samples
Samples around the summit inform the main rock-response profile, with the summit pin shown separately where it differs. Route samples add further context, but this is not a continuous geological survey.
Summit-area sample
Biotite graniteCairngorm Pluton, Phase 2625–1,242 m samplesSeen on Cairn Gorm, Cairn Gorm, 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
GraniteCairngorm Pluton, Phase 2Around 1,138 mSeen 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.
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 darkBetaNo sky forecast for this night yet. Moon and darkness times are shown separately.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
No sky forecast for this night yet. Moon and darkness times are shown separately.
A bright moon is up all through the dark hours, washing out fainter stars and meteors.
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 353 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.
Terrain at this viewpoint
Approximate terrain horizon at Cairn Gorm. Trees, buildings and nearby obstacles are not included.
Approximate bare-earth horizon, not surveyed sightlines. Narrow ridges may fall between samples. Trees, buildings and very close obstacles are not resolved. Valid only at the named summit coordinate, not on its slopes or at a lower campsite.
Mapzen Terrain Tiles. Europe terrain produced using Copernicus data and information funded by the European Union, EU-DEM layers. UK terrain: Environment Agency copyright and/or database right 2015. Global terrain: USGS and NOAA.
Contains Welsh Government public sector information licensed under the Open Government Licence v3.0.
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.
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 Cairn Gorm on Sunday 25 October 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Summit wind · 08:00-17:0010-30 mph southwesterlySummit gusts · 08:00-17:0025-35 mphFeels like-10 to -6°CPrecipitationUp to around 2 mmCloud-free summit estimate90%Freezing level800-1,100 mDaylightSunrise 07:11 · Sunset 16:44 · 9.6 hours daylight
The day on the hill
A mixed day on Cairn Gorm, with sleet or snow up high.
Snow and navigation
Blowing snow may quickly cover paths and footprints and make navigation difficult. 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 10–30 mph for most of the day, with gusts of 25–35 mph at the windiest. Lower down on the open hillside it will be more like 5–15 mph. Gusts like that will be noticeable on ridges and open tops, and you will chill quickly when you stop. It gets windier still after dark, with summit gusts of 30–40 mph, so bear that in mind if you will be out late.
Cloud and visibility
The tops should stay clear of cloud all day.
Rain and ground
A band of snow moves in around midday. The timing could shift by a few hours. The ground is very wet after recent rain, so expect boggy paths. 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 -10 to -6°C in the wind. It turns milder through the day. The freezing level is around 900–1200 m, so it will be below freezing on the tops. 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 4:45pm, 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.
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.
Morning · 08:00–12:00
MixedSummit winds around 10-20 mph early in the morning, strengthening to 15-25 mph later. Gusts around 25-35 mph are possible on exposed ground. Rain is possible during the morning, but forecast models disagree on whether it will fall. Rain is possible during the main walking period, but its timing may shift by several hours.
66
Afternoon · 12:00–17:00
PoorSummit winds around 20-30 mph. Gusts around 25-35 mph are possible on exposed ground. Rain is forecast during this period. Rain is possible during the main walking period, but its timing may shift by several hours.
40
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 and about 5 mm of rain.9Poor · 600 mView 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. Expect about 5 mm of rain, with rain while you pitch and still falling when you pack up. 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 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. The ground will be sodden after recent rain, so pick a firm, well-drained pitch.
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 / 46 mph
Typical / low
10.6°C / 6.7°C · several hours
In cloud
0% of modelled night
Condensation
High
600 m9 · very poor
Wind / gust
33 mph / 55 mph
Typical / low
9.2°C / 5.5°C · much of the night
In cloud
33% of modelled night
Condensation
High
900 m0 · very poor
Wind / gust
40 mph / 65 mph
Typical / low
7.5°C / 3.0°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.
The ground is likely to be very wet after recent rain. Expect boggy approaches and choose a durable pitch carefully.
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. 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 mphRain1.7 mm
Main factorsgusts of 25–35 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 graniteCairngorm 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
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.
Cairn Gorm
granite, gneiss or gabbro
Cairn Gorm
granite, gneiss or gabbro
Ben Macdui and Cairn Gorm
granite, gneiss or gabbro
Geological detail and BGS records
Mapped variation
2 rock types appear in the mapped samples
Samples around the summit inform the main rock-response profile, with the summit pin shown separately where it differs. Route samples add further context, but this is not a continuous geological survey.
Summit-area sample
Biotite graniteCairngorm Pluton, Phase 2625–1,242 m samplesSeen on Cairn Gorm, Cairn Gorm, 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
GraniteCairngorm Pluton, Phase 2Around 1,138 mSeen 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.
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 darkBetaNo sky forecast for this night yet. Moon and darkness times are shown separately.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
No sky forecast for this night yet. Moon and darkness times are shown separately.
A bright moon is up all through the dark hours, washing out fainter stars and meteors.
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 353 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.
Terrain at this viewpoint
Approximate terrain horizon at Cairn Gorm. Trees, buildings and nearby obstacles are not included.
Approximate bare-earth horizon, not surveyed sightlines. Narrow ridges may fall between samples. Trees, buildings and very close obstacles are not resolved. Valid only at the named summit coordinate, not on its slopes or at a lower campsite.
Mapzen Terrain Tiles. Europe terrain produced using Copernicus data and information funded by the European Union, EU-DEM layers. UK terrain: Environment Agency copyright and/or database right 2015. Global terrain: USGS and NOAA.
Contains Welsh Government public sector information licensed under the Open Government Licence v3.0.
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.
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 Cairn Gorm on Monday 26 October 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Summit wind · 08:00-17:0025-40 mph southwesterlySummit gusts · 08:00-17:0040-50 mphFeels like-10 to -6°CPrecipitationUp to around 2 mmCloud-free summit estimate85%Freezing level1,100-1,400 mDaylightSunrise 07:13 · Sunset 16:42 · 9.5 hours daylight
The day on the hill
A mixed day on Cairn Gorm, with a blustery wind.
Wind
On the summit expect a south-westerly wind of 25–40 mph for most of the day, with gusts of 40–50 mph at the windiest. Lower down on the open hillside it will be more like 10–20 mph. Gusts like that are strong enough to make walking into it hard work, with buffeting on ridges and edges. If the windier forecast models are right, summit gusts could reach 50–60 mph. It gets windier still after dark, with summit gusts of 40–50 mph, so bear that in mind if you will be out late.
Cloud and visibility
The tops should stay clear of cloud all day.
Rain and ground
Drizzle at first, clearing by midday. 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 falls through the day, to around 1300–1600 m by midday. Take a hat, gloves, a windproof and a spare warm layer.
Daylight
Sunset is around 4:40pm, so allow time to get off the hill before dark, and carry a head torch.
Forecast confidence
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 8.1 h of sunshine. This is not a forecast of time in sunshine on the summit. Use the cloud and views outlook above for the conditions on this mountain.
Morning · 08:00–12:00
MixedSummit winds around 25-35 mph. Gusts around 40-50 mph are possible on exposed ground. Gusts this strong can make walking into it hard work, with buffeting on ridges and edges. Rain is forecast during this period.
53
Afternoon · 12:00–17:00
MixedSummit winds around 30-40 mph. Gusts around 40-50 mph are possible on exposed ground. Gusts this strong can make walking into it hard work, with buffeting on ridges and edges.
51
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 60 mph.9Poor · 600 mView detailsHide details
Night beginning Tuesday 27 October 2026
Full overnight outlook
Not a night to camp on the open hill. Gusts reach about 60 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. 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.
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
28 mph / 41 mph
Typical / low
4.3°C / 3.5°C · much of the night
In cloud
0% of modelled night
Condensation
High
600 m9 · very poor
Wind / gust
34 mph / 50 mph
Typical / low
4.3°C / 3.5°C · much of the night
In cloud
0% of modelled night
Condensation
High
900 m9 · very poor
Wind / gust
39 mph / 58 mph
Typical / low
3.0°C / 2.2°C · much of the night
In cloud
60% of modelled night
Condensation
High
Warmth planning: As a broad starting point, consider a warm 3-season or 3–4 season bag with an ISO/EN comfort rating at or below about 0°C. Allow more margin if you sleep cold or expect fatigue, and use an adequate insulated mat. Dampness is possible, so keep the sleep system dry and ensure its insulation remains effective if damp.
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 40–50 mph could throw you off balance on exposed moves and ridges. 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 gust40-50 mphRain0.5 mm
Main factorsgusts of 40–50 mphwet rock likelySnow may fall on high ground. Deposits could make summer scrambling conditions inappropriate
Representative rock around the summit and along available routes
Biotite graniteCairngorm 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
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.
Cairn Gorm
granite, gneiss or gabbro
Cairn Gorm
granite, gneiss or gabbro
Ben Macdui and Cairn Gorm
granite, gneiss or gabbro
Geological detail and BGS records
Mapped variation
2 rock types appear in the mapped samples
Samples around the summit inform the main rock-response profile, with the summit pin shown separately where it differs. Route samples add further context, but this is not a continuous geological survey.
Summit-area sample
Biotite graniteCairngorm Pluton, Phase 2625–1,242 m samplesSeen on Cairn Gorm, Cairn Gorm, 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
GraniteCairngorm Pluton, Phase 2Around 1,138 mSeen 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.
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 darkBetaNo sky forecast for this night yet. Moon and darkness times are shown separately.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
No sky forecast for this night yet. Moon and darkness times are shown separately.
A bright moon is up all through the dark hours, washing out fainter stars and meteors.
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 353 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.
Terrain at this viewpoint
Approximate terrain horizon at Cairn Gorm. Trees, buildings and nearby obstacles are not included.
Approximate bare-earth horizon, not surveyed sightlines. Narrow ridges may fall between samples. Trees, buildings and very close obstacles are not resolved. Valid only at the named summit coordinate, not on its slopes or at a lower campsite.
Mapzen Terrain Tiles. Europe terrain produced using Copernicus data and information funded by the European Union, EU-DEM layers. UK terrain: Environment Agency copyright and/or database right 2015. Global terrain: USGS and NOAA.
Contains Welsh Government public sector information licensed under the Open Government Licence v3.0.
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.
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 Cairn Gorm on Tuesday 27 October 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Summit wind · 08:00-17:0030-45 mph westerlySummit gusts · 08:00-17:0050-60 mphFeels like-10 to -6°CPrecipitationUp to around 2 mmCloud-free summit estimate90%Cloud base through day1,400-1,700 mFreezing level1,200-1,500 mDaylightSunrise 07:15 · Sunset 16:40 · 9.4 hours daylight
The day on the hill
A poor day on the tops of Cairn Gorm, with very strong, gusty winds and sleet or snow up high.
Wind
On the summit expect a westerly wind of 30–45 mph for most of the day, with gusts of 50–60 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 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 60–70 mph.
Cloud and visibility
The tops should stay mostly clear of cloud. A few forecast models bring the cloud base down to around 600–900 m at times. The cloud base sits close to summit height, so the top could go in and out of cloud at short notice. Mist or fog is possible in the valleys early on, clearing by about 7am. It will look largely cloudy overhead, but that cloud should mostly stay above the tops.
Rain and ground
Sleet is possible on the tops, and it could turn to snow if it is a little colder. Drizzle at first, clearing by midday. Expect up to 2 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 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 4:40pm, so allow time to get off the hill before dark, and carry a head torch.
Forecast confidence
It's still seven days off and could change, so check again nearer the time.
Sunshine context Model-grid estimate, not summit sunshine
The surrounding model grid indicates 6.4 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.
Morning · 08:00–12:00
PoorSummit 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.
32
Afternoon · 12:00–17:00
PoorSummit winds around 30-40 mph. Gusts around 45-55 mph are possible on exposed ground. Gusts this strong can knock you off balance, so take care near edges and on narrow ridges.
47
Compare an early start with later conditions. The main forecast above covers the day in more detail.
Overnight · 17:00–08:00Wild campingBetaToo windy for an exposed pitch above about 600 m (gusts of about 50 mph). Lower down, a poor night to camp on open ground.19Poor · 600 mView detailsHide details
Night beginning Wednesday 28 October 2026
Full overnight outlook
Too windy for an exposed pitch above about 600 m. Lower down, a poor night to camp on open ground. Gusts reach about 50 mph around 900 m and nearer 35 mph around 300 m, enough to damage a tent on open ground. Pitch low down and in real shelter, or leave it for another night. Expect a little rain, mostly early on, so you'll likely pitch in the rain. Up around 900 m you'd likely be in cloud for part of the night: damp, and hard to find your way if you need to move. The air is damp at every height we checked (300-900 m), so expect heavy condensation. Leave the vents open. A cold night, down to about 2°C around 900 m. A warm 3-season or 3–4 season bag rated to about 0°C comfort, and a warm mat, should do. Allow more if you sleep cold.
Extensive cloud may limit moonlight. Illumination describes the sunlit part of the Moon, not brightness at your pitch.
Overnight window: 28 Oct, 17:00 GMT to 29 Oct, 08:00 GMT. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.
Elevation reference (open ground)
300 m39 · poor
Wind / gust
24 mph / 35 mph
Typical / low
3.3°C / 3.0°C · much of the night
In cloud
0% of modelled night
Condensation
High
600 m19 · very poor
Wind / gust
29 mph / 42 mph
Typical / low
3.3°C / 3.0°C · much of the night
In cloud
0% of modelled night
Condensation
High
900 m9 · very poor
Wind / gust
34 mph / 50 mph
Typical / low
2.4°C / 2.2°C · much of the night
In cloud
60% of modelled night
Condensation
High
Warmth planning: As a broad starting point, consider a warm 3-season or 3–4 season bag with an ISO/EN comfort rating at or below about 0°C. Allow more margin if you sleep cold or expect fatigue, and use an adequate insulated mat. Dampness is possible, so keep the sleep system dry and ensure its insulation remains effective if damp.
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 50–60 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 gust50-60 mphRain1.3 mm
Main factorsgusts of 50–60 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 graniteCairngorm 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
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.
Cairn Gorm
granite, gneiss or gabbro
Cairn Gorm
granite, gneiss or gabbro
Ben Macdui and Cairn Gorm
granite, gneiss or gabbro
Geological detail and BGS records
Mapped variation
2 rock types appear in the mapped samples
Samples around the summit inform the main rock-response profile, with the summit pin shown separately where it differs. Route samples add further context, but this is not a continuous geological survey.
Summit-area sample
Biotite graniteCairngorm Pluton, Phase 2625–1,242 m samplesSeen on Cairn Gorm, Cairn Gorm, 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
GraniteCairngorm Pluton, Phase 2Around 1,138 mSeen 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.
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 Cairn Gorm on Wednesday 28 October 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
