The day on the hill
Frequent summit cloud on Seana Bhràigh: summit wind broadly 15-25 mph, with gusts 25-35 mph at times (a fresh breeze). Visibility may drop briefly in showers.
Cloud & views
Cloud base around 600–900 m in the morning, then around 1000–1300 m around midday and 800–1100 m by late afternoon. The top is likely to drift in and out of cloud, with the best chance of a view around midday.
Cloud-height uncertainty could put the summit in or out of cloud. Clear spells may be difficult to time.
Cloud may hang lower on western slopes and lift somewhat on the eastern 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.
Drizzle is forecast at times, with some passing showers too. The forecast total is up to around 2 mm, but local amounts will vary.
Cold on exposed tops: air temperature broadly 2 to 6°C, feeling around -4 to 0°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.
If clothing gets wet, you can cool more quickly. Keep a dry warm layer protected.
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 15% early, improving to around 40% later.
Sunshine context Model-grid estimate, not summit sunshine
The surrounding model grid indicates 1.2 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.
- Early
- 0 h
- Midday
- Less than 1 hour
- Later
- 0.8 h
Overnight forecast: 17:00–08:00 (UK local time), in Wild camping below.
Overnight · 17:00–08:00Wild campingBetaGusts near 35 mph make meaningful shelter important. 59/100Mixed · 600 m View detailsHide details
Full overnight outlook
Open-hillside camping looks mixed overall around 600 m (59/100). A lower pitch near 300 m looks more comfortable. Conditions are less suitable by 900 m. Open-ground gusts may reach about 35 mph. Seek meaningful shelter. Peak gusts range from about 25 mph at 300 m to 35 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. Condensation risk is high near 900 m. Ventilation will matter. The coldest temperature falls from about 5.6°C at 300 m to 3.7°C at 900 m.
Moon overnight
Waxing gibbous moon
- Illuminated disc
- 92%
- Moonrise
- 18:30 BST
- Moonset
- 03:58 next morning BST
Views of the Moon may come and go through cloud breaks. 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
- 10 mph / 25 mph
- Typical / low
- 5.9°C / 5.6°C · much of the night
- In cloud
- 0% of modelled night
- Condensation
- Moderate
- Wind / gust
- 12 mph / 30 mph
- Typical / low
- 5.9°C / 5.6°C · much of the night
- In cloud
- 0% of modelled night
- Condensation
- Moderate
- Wind / gust
- 15 mph / 35 mph
- Typical / low
- 4.1°C / 3.7°C · much of the night
- In cloud
- 80% 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 & scramblingBetaWet rock is likely. Poor12/100 View detailsHide details
Full climbing & scrambling outlook
Conditions for exposed scrambling look very poor (12/100). Rain during the climbing period is likely to leave rock wet and more slippery. The mapped summit rock is Psammite (Glascarnoch Psammite Formation). Dry quartz-rich bands can be grippy, while mica-rich or foliated sections, lichen and vegetation may become slippery when wet. Representative samples along available mapped routes also include Garnet semipelite, so rock character and wet-weather behaviour may change across the mountain. 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.
Seana Bhràigh
psammite, pelite or semipelite
Geological detail and BGS records
2 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.
Dry quartz-rich bands can be grippy, while mica-rich or foliated sections, lichen and vegetation may become slippery when wet.
BGS recordDry quartz-rich bands can be grippy, while mica-rich or foliated sections, lichen and vegetation may become slippery when wet.
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 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: 24 Sep, 01:00 BST to 02:00 BST.
Look north-north-west, well up in 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.
Could be bright enough to see moving rays and colour with the naked eye.
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, 21:30 BST to 22:00 BST | Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars. |
| 23 Sep, 22:00 BST to 23:00 BST | Mixed 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 | Mixed sky conditions Clearer spells are possible, but other forecasts keep much of the sky obscured by cloud. Forecast models disagree. |
| 24 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. |
| 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 Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects. |
| 24 Sep, 04:00 BST to 04:55 BST | Poor sky conditions Cloud is likely to obscure much of the sky. |
Moon, darkness and meteor showers
Gibbous moon, about 92% illuminated.
Moonrise around 23 Sep, 18:30 BST.
Moonset around 24 Sep, 03:50 BST.
Full darkness: 23 Sep, 21:30 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 198 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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