The day on the hill
Serious conditions on Cairn Gorm, with strong, gusty winds and the summit in cloud for most of the day. Think carefully before heading high.
Wind
On the summit expect a south-easterly 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 15–25 mph. Gusts like that are strong enough to knock you off balance, so take care near edges and on narrow ridges.
Cloud and visibility
Expect the summit to be in cloud for most of the day. The cloud base could be as low as 400–700 m in the late 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. Mist or fog is possible in the valleys early on, clearing by about 1am.
Rain and ground
Drizzle at first, clearing by early afternoon. Expect 2–5 mm in total. Some forecast models keep it drier in the afternoon.
Warmth and kit
On the tops it will be around 0 to 4°C, feeling like -8 to -4°C in the wind. The freezing level is above the summits. Take a hat, gloves, a windproof and a spare warm layer. Pack waterproofs too, and keep a warm layer dry in your pack.
Daylight
Sunset is around 6pm, 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.
Below zero means severe hill conditions. More negative scores indicate more severe forecast weather. Read the hazard details before making plans. Below zero means severe hill conditions. More negative scores indicate more severe forecast weather. Read the hazard details before making plans.
Sunshine context Model-grid estimate, not summit sunshine
The surrounding model grid indicates 0 h of sunshine. This is not a forecast of time in sunshine on the summit. Use the cloud and views outlook above for the conditions on this mountain.
- Early
- 0 h
- Midday
- 0 h
- Later
- 0 h
Overnight forecast: 17:00–08:00 (UK local time), in Wild camping below.
Overnight · 17:00–08:00Wild campingBetaToo windy for an exposed pitch up around 900 m (gusts of about 45 mph and about 6 mm of rain). Lower down, a mixed night to camp, mainly because of the wind. 39Poor · 600 m View detailsHide details
Full overnight outlook
Too windy for an exposed pitch up around 900 m. Lower down, a mixed night to camp, mainly because of the wind. Gusts reach about 45 mph around 900 m and nearer 30 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. Dry to pitch, then about 6 mm of rain overnight and into the morning, so expect to pack a wet tent. Above about 600 m you'd likely be in cloud for part of the night: damp, and hard to find your way if you need to move. A cold night, down to about 2°C around 900 m. A 3-season bag rated to about 2°C comfort, and a warm mat, should do. Allow more if you sleep cold.
Moon overnight
Waxing gibbous moon
- Illuminated disc
- 72%
- Moonrise
- Outside this window
- Moonset
- 01:29 next morning BST
Cloud at the reference camping height may hide the Moon. Illumination describes the sunlit part of the Moon, not brightness at your pitch.
Overnight window: 20 Oct, 17:00 BST to 21 Oct, 08:00 BST. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.
Elevation reference (open ground)
- Wind / gust
- 22 mph / 32 mph
- Typical / low
- 5.9°C / 5.3°C · much of the night
- In cloud
- 0% of modelled night
- Condensation
- High
- Wind / gust
- 26 mph / 39 mph
- Typical / low
- 5.2°C / 4.2°C · several hours
- In cloud
- 100% of modelled night
- Condensation
- High
- Wind / gust
- 31 mph / 46 mph
- Typical / low
- 3.3°C / 2.3°C · much of the night
- In cloud
- 100% of modelled night
- Condensation
- High
Warmth planning: As a broad starting point, consider a 3-season bag with an ISO/EN comfort rating at or below about 2°C. Allow more margin if you sleep cold or expect fatigue, and use an adequate insulated mat. Dampness is possible, so keep the sleep system dry and ensure its insulation remains effective if damp.
Open-hillside reference. A sheltered pitch may be calmer; cols and ridges may be much windier. Tent design and the exact pitch still matter. Read about sleeping-bag comfort ratings, pitching in strong winds or using the wild-camping forecast.
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Daytime · exposed rockClimbing & scramblingBetaVery poor conditions for exposed scrambling: gusts of 40–50 mph. Poor0 View detailsHide details
Full climbing & scrambling outlook
Very poor conditions for exposed scrambling. The rock is likely to be wet and slippery through the day. Gusts of 40–50 mph could throw you off balance on exposed moves and ridges. Cloud on the tops may make route-finding and retreat harder. The rock around the summit is mostly 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.
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
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.
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 recordGranite 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 recordGeneric exposed scrambling terrain; BGS summit-area bedrock samples are included where available, but route grade, exact rock, polish, drainage and escape options remain unresolved. Contains British Geological Survey materials © UKRI 2026. How to use the climbing and scrambling forecast.
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Overnight · Aurora, stars & meteorsAfter darkBetaMostly cloudy, so little chance of seeing the stars. Moonlight washes out the fainter stars. View forecastClose forecast
After dark: aurora and stargazing
Night beginning 2026-10-20. 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 4.7 (on a 0 to 9 scale). NOAA has a G1 storm watch out for this date, though the timing of the strongest activity can shift.
Activity can change at short notice. Check again on the night.
Stargazing
Poor sky conditions during the best available spell: 20 Oct, 20:05 BST to 21:00 BST.
Mostly cloudy, so little chance of seeing the stars. Moonlight washes out the fainter stars.
Moon-free dark sky: 21 Oct, 01:25 BST to 05:50 BST.
Sky conditions through the night
| Time | Viewing conditions |
|---|---|
| 20 Oct, 20:05 BST to 21:00 BST | Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Moonlight washes out the fainter stars. |
| 20 Oct, 21:00 BST to 22:00 BST | Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Moonlight washes out the fainter stars. |
| 20 Oct, 22:00 BST to 23:00 BST | Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Moonlight washes out the fainter stars. |
| 20 Oct, 23:00 BST to 21 Oct, 00:00 BST | Poor sky conditions Mostly cloudy, so little chance of seeing the stars. |
| 21 Oct, 00:00 BST to 01:00 BST | Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. |
| 21 Oct, 01:00 BST to 02:00 BST | Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. |
| 21 Oct, 02:00 BST to 03:00 BST | Poor sky conditions Mostly cloudy, so little chance of seeing the stars. Rain at times. |
| 21 Oct, 03:00 BST to 04:00 BST | Poor sky conditions Mostly cloudy, so little chance of seeing the stars. |
| 21 Oct, 04:00 BST to 05:00 BST | Poor sky conditions Mostly cloudy, so little chance of seeing the stars. |
| 21 Oct, 05:00 BST to 05:50 BST | Poor sky conditions Mostly cloudy, so little chance of seeing the stars. |
Moon, darkness and meteor showers
Gibbous moon, about 72% illuminated.
Moonset around 21 Oct, 01:25 BST.
Full darkness: 20 Oct, 20:05 BST to 21 Oct, 05:50 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.
Explore the dedicated aurora forecast, meteor shower forecast or dark-sky and astrophotography forecast.
Recommended kit for this dayWeather-aware packing prompts, plus your core hillwalking kitView kit
For a day hillwalk, not a complete route-specific checklist. Carry navigation and backup you can use, warm and waterproof layers, suitable footwear, food and water, a headtorch, emergency shelter, first aid and a way to call for help. Snow, ice, technical terrain and overnight trips need additional equipment and skills.
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