The day on the hill
Little rain and limited summit cloud on Sron a' Choire Chnapanich: summit wind broadly 10-25 mph, with gusts 20-30 mph at times (a moderate breeze).
Things to watch
Severe spate risk during the morning, after earlier rain. 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 around 600–900 m in the morning, lifting to 1000–1300 m around midday. Summit cloud is extensive early, becoming less frequent later.
Cloud-height uncertainty could put the summit in or out of cloud. Clear spells may be difficult to time.
Cloud may hang lower on northwestern slopes and lift somewhat on the southeastern side, but local terrain can differ. Sunny spells are possible away from summit cloud, but may not reach the top while it is in cloud.
Rain & temperature
The ground is likely to be wet after recent rain. Little or no rain is forecast.
Cold on exposed tops: air temperature broadly 2 to 6°C, feeling around -2 to 2°C in the wind.
Forecast confidence
Cloud height remains uncertain, especially where it is close to summit level. Keep windproof and warm layers readily available.
Cloud-height uncertainty could put the summit in or out of cloud, even where forecasts agree on the wider cloud cover.
Cloud-free timing: Around 25% early, improving to around 70% later.
Sunshine context Model-grid estimate, not summit sunshine
The surrounding model grid indicates 4 h of sunshine. This is not a forecast of time in sunshine on the summit. Use the cloud and views outlook above for the conditions on this mountain.
- Early
- 0 h
- Midday
- 1.6 h
- Later
- 1 h
Overnight forecast: 17:00–08:00 (UK local time), in Wild camping below.
Overnight · 17:00–08:00Wild campingBetaA cold night is forecast near 900 m, with the cold lasting much of the night. 85/100Excellent · 600 m View detailsHide details
Full overnight outlook
Open-hillside camping looks promising overall around 600 m (85/100). 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 30 mph. Peak gusts range from about 20 mph at 300 m to 30 mph at 900 m. Wind direction may change substantially during the night. Shelter that works at dusk may be less effective later. Little overnight rain is forecast. Pitches near 900 m may spend part of the night in cloud, bringing damp conditions and poor visibility while cloud is present. The coldest temperature falls from about 5.9°C at 300 m to 3.6°C at 900 m.
Moon overnight
Waxing gibbous moon
- Illuminated disc
- 92%
- Moonrise
- 18:24 BST
- Moonset
- 04:00 next morning BST
Clear spells may allow a view of the Moon. Illumination describes the sunlit part of the Moon, not brightness at your pitch.
Overnight window: 23 Sep, 17:00 BST to 24 Sep, 08:00 BST. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.
Elevation reference (open ground)
- Wind / gust
- 8 mph / 20 mph
- Typical / low
- 6.6°C / 5.9°C · much of the night
- In cloud
- 0% of modelled night
- Condensation
- Low
- Wind / gust
- 10 mph / 24 mph
- Typical / low
- 6.6°C / 5.9°C · much of the night
- In cloud
- 0% of modelled night
- Condensation
- Low
- Wind / gust
- 12 mph / 28 mph
- Typical / low
- 4.2°C / 3.6°C · much of the night
- In cloud
- 27% of modelled night
- Condensation
- Moderate
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. Poor36/100 View detailsHide details
Full climbing & scrambling outlook
Conditions for exposed scrambling look poor (36/100). Recent rain may leave seepage and damp rock, especially on shaded sections. The mapped summit rock is Calcareous pelite (Ben Lawers Schist Formation). Dry quartz-rich bands can be grippy, while mica-rich or foliated sections, lichen and vegetation may become slippery when wet.
Dry quartz-rich bands can be grippy, while mica-rich or foliated sections, lichen and vegetation may become slippery when wet. Summit-point bedrock mapping; the actual route may cross different rock, superficial deposits, polish, lichen or seepage.
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 darkBetaSome potential for aurora on this night View forecastClose forecast
After dark: aurora and stargazing
Night beginning 2026-09-23. All times are UK local time.
Some potential for aurora on this night
Space-weather forecasts suggest activity could be strong enough for aurora at this location. Forecast activity peaks near Kp 5.3 on the 0 to 9 scale.
Best forecast window: 23 Sep, 22:00 BST to 23:00 BST.
Look north-north-west, from the horizon part-way up the sky. A clear, open view that way matters more than height.
A bright Moon is above the horizon around the best forecast hour and may wash out faint aurora detail. A stronger display may still be visible.
Aurora viewing guidance
Cloud is sampled overhead and towards the northern viewing horizon. Narrow cloud bands can still be missed. Forecast models disagree on cloud towards the viewing horizon.
The terrain horizon has not been checked at this exact location. Nearby slopes or a lower campsite can have a very different view.
Relatively little surrounding artificial light lies towards the aurora compared with other assessed peaks.
Most likely a faint glow low in the sky that a phone camera shows better than your eyes. It can look like thin cloud.
Not sure what you are seeing? Take a Night-mode photo facing north: rest the phone on a rock or pack, use the main lens and a timer, and hold still for a 3–10 second exposure. Cameras show aurora colour long before eyes do.
Aurora activity can change quickly. This is experimental guidance, not a guaranteed sighting. Check again before heading out.
Stargazing
Mixed sky conditions during the best available spell: 24 Sep, 02:00 BST to 03:00 BST.
Clearer spells are possible, but other forecasts keep much of the sky obscured by cloud.
Moon-free dark sky: 24 Sep, 03:50 BST to 04:55 BST.
Sky conditions through the night
| Time | Viewing conditions |
|---|---|
| 23 Sep, 21:25 BST to 22:00 BST | Mixed sky conditions Cloud breaks may offer some views of the stars. Moonlight washes out fainter stars. |
| 23 Sep, 22:00 BST to 23:00 BST | Poor sky conditions Clearer spells are possible, but other forecasts keep much of the sky obscured by cloud. Forecast models disagree. |
| 23 Sep, 23:00 BST to 24 Sep, 00:00 BST | Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars. |
| 24 Sep, 00:00 BST to 01:00 BST | Poor sky conditions Clearer spells are possible, but other forecasts keep much of the sky obscured by cloud. Forecast models disagree. |
| 24 Sep, 01:00 BST to 02:00 BST | Mixed sky conditions Clearer spells are possible, but other forecasts keep much of the sky obscured by cloud. Forecast models disagree. |
| 24 Sep, 02:00 BST to 03:00 BST | Mixed sky conditions Clearer spells are possible, but other forecasts keep much of the sky obscured by cloud. Forecast models disagree. |
| 24 Sep, 03:00 BST to 04:00 BST | Poor sky conditions Clearer spells are possible, but other forecasts keep much of the sky obscured by cloud. Forecast models disagree. |
| 24 Sep, 04:00 BST to 04:55 BST | Poor sky conditions Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects. |
Moon, darkness and meteor showers
Gibbous moon, about 92% illuminated.
Moonrise around 23 Sep, 18:25 BST.
Moonset around 24 Sep, 03:50 BST.
Full darkness: 23 Sep, 21:25 BST to 24 Sep, 04:55 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.
- 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 395 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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