The day on the hill
Frequent summit cloud on Sgùrr a' Mhadaidh: summit wind broadly 10-25 mph, with gusts 25-35 mph at times (a fresh breeze).
Cloud & views
Cloud base around 600–900 m through the morning, lifting to 3100–3400 m by late afternoon. Cloud is likely to cover the top for much of the day, though a brief clearance is possible during the afternoon.
Cloud-height uncertainty could put the summit in or out of cloud. Clear spells may be difficult to time.
Any sunshine may be confined to lower ground or breaks away from the summit.
Rain & temperature
Little or no rain is forecast.
Forecast confidence
Cloud height remains uncertain, especially where it is close to summit level. Exposed tops may feel chilly in the wind.
A windproof layer will help, with an extra warm layer for stops. Forecast models differ on whether meaningful rain reaches the hills during the morning.
Cloud-free timing: Around 20% early, improving to around 65% later.
Sunshine context Model-grid estimate, not summit sunshine
The surrounding model grid indicates 3.3 h of sunshine. This is not a forecast of time in sunshine on the summit. Use the cloud and views outlook above for the conditions on this mountain.
Cloud may obscure this summit even while the surrounding model grid indicates sunshine. The low cloud-free summit estimate is a reason to be cautious about expecting views.
- Early
- 0 h
- Midday
- 2.3 h
- Later
- Less than 1 hour
Overnight forecast: 17:00–08:00 (UK local time), in Wild camping below.
Overnight · 17:00–08:00Wild campingBetaAbout 2.1 mm is forecast, with rain possible around pack-up. 77/100Good · 600 m View detailsHide details
Full overnight outlook
Open-hillside camping looks promising overall around 600 m (77/100). A lower pitch near 300 m looks more comfortable. Conditions are less suitable by 900 m. It may be breezy on open ground, with gusts near 20 mph. Peak gusts range from about 15 mph at 300 m to 20 mph at 900 m. Around 2.1 mm is forecast, including rain around pack-up. Pitches near 900 m may spend part of the night in cloud, bringing damp conditions and poor visibility while cloud is present. Condensation risk is high near 900 m. Ventilation will matter. The coldest temperature falls from about 6.5°C at 300 m to 4.4°C at 900 m.
Moon overnight
Waxing gibbous moon
- Illuminated disc
- 86%
- Moonrise
- 18:26 BST
- Moonset
- 02:40 next morning BST
Extensive cloud may limit moonlight. Illumination describes the sunlit part of the Moon, not brightness at your pitch.
Overnight window: 22 Sep, 17:00 BST to 23 Sep, 08:00 BST. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.
Elevation reference (open ground)
- Wind / gust
- 9 mph / 16 mph
- Typical / low
- 7.6°C / 6.5°C · much of the night
- In cloud
- 0% of modelled night
- Condensation
- Moderate
- Wind / gust
- 11 mph / 19 mph
- Typical / low
- 7.6°C / 6.5°C · much of the night
- In cloud
- 0% of modelled night
- Condensation
- Moderate
- Wind / gust
- 13 mph / 22 mph
- Typical / low
- 5.9°C / 4.4°C · a brief spell
- In cloud
- 60% of modelled night
- Condensation
- High
Warmth planning: As a broad starting point, consider a 3-season bag with an ISO/EN comfort rating at or below about 4°C. Allow more margin if you sleep cold or expect fatigue, and use an adequate insulated mat. Dampness is possible, so keep the sleep system dry and ensure its insulation remains effective if damp.
Open-hillside reference. A sheltered pitch may be calmer; cols and ridges may be much windier. Tent design and the exact pitch still matter. Read about sleeping-bag comfort ratings, pitching in strong winds or using the wild-camping forecast.
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Daytime · exposed rockClimbing & scramblingBetaRock may be damp or still drying. Poor0/100 View detailsHide details
Full climbing & scrambling outlook
Conditions for exposed scrambling look very poor (0/100). Recent rain may leave seepage and damp rock, especially on shaded sections. The mapped summit rock is Basalt and microgabbro (North Britain Palaeogene Dyke Suite). Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery. Representative samples along available mapped routes also include Olivine-gabbro, Bytownite troctolite and 2 other mapped types, so rock character and wet-weather behaviour may change across the mountain. Cloud may also make route-finding and retreat harder.
Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery. Summit-point mapping plus representative BGS bedrock samples along available GPX routes. These are not continuous geological surveys; contacts, superficial deposits and the exposed rock on individual holds may differ.
Rock groups along the sampled routes
These are mapped rock groups, not separate weather forecasts or a ranking of route safety.
Sgùrr a' Ghreadaidh and Sgùrr a' Mhadaidh
granite, gneiss or gabbro
Geological detail and BGS records
5 rock types appear across the available route samples
The summit type remains the forecast's cautious rock-response reference. Other mapped types show where conditions may behave differently elsewhere on the mountain.
Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery.
BGS recordGenerally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery.
BGS recordGenerally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery.
BGS recordGenerally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery.
BGS recordGenerally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery.
BGS recordGeneric exposed scrambling terrain; mapped summit-point bedrock is 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 darkBetaCloud is likely to obscure much of the sky. View forecastClose forecast
After dark: aurora and stargazing
Night beginning 2026-09-22. All times are UK local time.
Stargazing
Poor sky conditions during the best available spell: 23 Sep, 03:00 BST to 04:00 BST.
Cloud is likely to obscure much of the sky.
Moon-free dark sky: 23 Sep, 02:30 BST to 05:00 BST.
Sky conditions through the night
| Time | Viewing conditions |
|---|---|
| 22 Sep, 21:35 BST to 22:00 BST | Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars. |
| 22 Sep, 22:00 BST to 23:00 BST | Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars. |
| 22 Sep, 23:00 BST to 23 Sep, 00:00 BST | Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars. |
| 23 Sep, 00:00 BST to 01:00 BST | Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars. |
| 23 Sep, 01:00 BST to 02:00 BST | Poor sky conditions Cloud is likely to obscure much of the sky. |
| 23 Sep, 02:00 BST to 03:00 BST | Poor sky conditions Cloud is likely to obscure much of the sky. |
| 23 Sep, 03:00 BST to 04:00 BST | Poor sky conditions Cloud is likely to obscure much of the sky. |
| 23 Sep, 04:00 BST to 05:00 BST | Poor sky conditions Cloud is likely to obscure much of the sky. |
Moon, darkness and meteor showers
Gibbous moon, about 85% illuminated.
Moonrise around 22 Sep, 18:30 BST.
Moonset around 23 Sep, 02:30 BST.
Full darkness: 22 Sep, 21:35 BST to 23 Sep, 05:00 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.
- Draconids: peak around 9 October 2026.
- 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 25 of 980 assessed peaks (1 is darkest), based on surrounding artificial light in 2021. This is not a measurement of tonight’s sky.
2021 artificial-light baseline, not measured sky brightness or a Bortle class. Changes to lighting, blue-rich LEDs, terrain screening, atmospheric scattering and cloud-reflected light are not resolved. Similar ranks are not meaningfully distinct. Darkness is not a recommendation to climb a summit at night.
VIIRS nighttime lights: Earth Observation Group, Payne Institute for Public Policy, Colorado School of Mines. Reprocessed by OpenGeoHub/OpenLandMap. Cropped and ranked by Mountain Weather.
Sky-weather grades exclude light pollution, terrain and thin haze. They are not mountain safety ratings. Check the mountain and camping forecast separately. Accessible lower viewpoints may be a better choice than summits.
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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