The day on the hill
Frequent summit cloud on Mullach Clach a' Bhlàir: summit wind broadly 10-25 mph, with gusts 25-35 mph at times (a fresh breeze). Hill cloud may make navigation difficult, with very poor visibility in wetter spells.
Things to watch
High spate risk from the evening into the night, with forecast rain and subsequent runoff. Risk may continue beyond the daytime period shown. Timings are approximate, not a guarantee of safe crossings afterwards. Burns and unbridged crossings may become difficult or impassable. Turn back if a crossing looks unsafe.
Cloud & views
Cloud base mostly around 600–900 m through daylight. Summit cloud is likely, but brief clear spells remain possible if the cloud sits higher than expected.
Cloud-height uncertainty could put the summit in or out of cloud. Clear spells may be difficult to time.
Cloud may hang lower on southwestern slopes and lift somewhat on the northeastern side, but local terrain can differ. Very little direct sunshine is likely, with extensive cloud.
Rain & temperature
Rain and drizzle are forecast at times, with some passing showers too. The forecast total is around 5-10 mm, but local amounts will vary.
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. If clothing gets wet, you can cool more quickly.
Keep a dry warm layer protected. Rain is forecast during late afternoon and evening, but models differ considerably on the amount.
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 campingBetaAbout 40.2 mm is forecast, with rain liable to affect both pitching and packing up. 39/100Poor · 600 m View detailsHide details
Full overnight outlook
Open-hillside camping looks poor overall around 600 m (39/100). 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. Roughly 40.2 mm is forecast overnight, with rain liable to affect both pitching and packing 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 300, 600 and 900 m. Ventilation will matter. The coldest temperature falls from about 6.9°C at 300 m to 5.2°C at 900 m.
Moon overnight
Waxing gibbous moon
- Illuminated disc
- 86%
- Moonrise
- 18:15 BST
- Moonset
- 02:31 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
- 7 mph / 16 mph
- Typical / low
- 11.6°C / 6.9°C · several hours
- In cloud
- 0% of modelled night
- Condensation
- High
- Wind / gust
- 8 mph / 19 mph
- Typical / low
- 11.6°C / 6.9°C · several hours
- In cloud
- 13% of modelled night
- Condensation
- High
- Wind / gust
- 10 mph / 22 mph
- Typical / low
- 9.2°C / 5.2°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 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 & scramblingBetaWet rock is likely. Poor0/100 View detailsHide details
Full climbing & scrambling outlook
Conditions for exposed scrambling look very poor (0/100). Rain during the climbing period is likely to leave rock wet and more slippery. The mapped summit rock is Psammite (Gaick Psammite Formation). Dry quartz-rich bands can be grippy, while mica-rich or foliated sections, lichen and vegetation may become slippery when wet. Cloud may also make route-finding and retreat harder.
Dry quartz-rich bands can be grippy, while mica-rich or foliated sections, lichen and vegetation may become slippery when wet. 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.
Mullach Clach a' Bhlàir
psammite, pelite or semipelite
Generic 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. Rain may interrupt viewing. Moonlight washes out fainter stars. 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: 22 Sep, 21:25 BST to 22:00 BST.
Cloud is likely to obscure much of the sky. Rain may interrupt viewing. Moonlight washes out fainter stars.
Moon-free dark sky: 23 Sep, 02:20 BST to 04:50 BST.
Sky conditions through the night
| Time | Viewing conditions |
|---|---|
| 22 Sep, 21:25 BST to 22:00 BST | Poor sky conditions Cloud is likely to obscure much of the sky. Rain may interrupt viewing. 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. Rain may interrupt viewing. 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. Rain may interrupt viewing. Reduced visibility may obscure faint objects. 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. Rain may interrupt viewing. 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. Rain may interrupt viewing. |
| 23 Sep, 02:00 BST to 03:00 BST | Poor sky conditions Cloud is likely to obscure much of the sky. Rain may interrupt viewing. Reduced visibility may obscure faint objects. |
| 23 Sep, 03:00 BST to 04:00 BST | Poor sky conditions Cloud is likely to obscure much of the sky. Rain may interrupt viewing. Reduced visibility may obscure faint objects. |
| 23 Sep, 04:00 BST to 04:50 BST | Poor sky conditions Cloud is likely to obscure much of the sky. Rain may interrupt viewing. |
Moon, darkness and meteor showers
Gibbous moon, about 85% illuminated.
Moonrise around 22 Sep, 18:20 BST.
Moonset around 23 Sep, 02:20 BST.
Full darkness: 22 Sep, 21:25 BST to 23 Sep, 04:50 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.
- 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 275 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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