The day on the hill
On Allt-Fawr: summit wind broadly 15-30 mph, with gusts 30-40 mph at times (strong winds).
Things to watch
Thunderstorms are possible during the morning. Avoid committing to exposed ridges if storms begin to build.
If a thunderstorm develops, sudden gusts and heavy rain can change conditions quickly. Severe spate risk from the morning into the afternoon, with forecast rain and subsequent runoff. 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 and 1300–1600 m by late afternoon. 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.
Sunny spells are possible away from summit cloud, but may not reach the top while it is in cloud.
Rain & temperature
Rain is likely to include a heavy spell, with around 20-40 mm expected over the assessed day. Forecast models differ on summit wind strength: around 22-28 mph at walker height, with gusts 31-40 mph.
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. Buffeting may affect balance on exposed ground, particularly near ridges and edges.
Thunderstorm timing is inherently uncertain and may shift by several hours.
Cloud-free timing: Around 40% early, improving to around 95% later.
Sunshine context Model-grid estimate, not summit sunshine
The surrounding model grid indicates 7 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
- 4 h
- Later
- 2 h
Overnight forecast: 17:00–08:00 (UK local time), in Wild camping below.
Overnight · 17:00–08:00Wild campingBetaConditions look very good, but forecast uncertainty caps the grade at 92/100. 92/100Excellent · 600 m View detailsHide details
Full overnight outlook
Open-hillside camping looks very good overall around 600 m (92/100). It may be breezy on open ground, with gusts near 25 mph. Little overnight rain is forecast. The forecast does not have sufficiently broad dry and light-wind support for an exceptional grade. The grade is capped at 92/100.
Moon overnight
Waxing gibbous moon
- Illuminated disc
- 92%
- Moonrise
- 18:10 BST
- Moonset
- 04:08 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 / 20 mph
- Typical / low
- 8.7°C / 8.5°C · much of the night
- In cloud
- 0% of modelled night
- Condensation
- Low
- Wind / gust
- 12 mph / 24 mph
- Typical / low
- 8.7°C / 8.5°C · much of the night
- In cloud
- 0% of modelled night
- Condensation
- Low
Warmth planning: As a broad starting point, consider a 3-season bag with an ISO/EN comfort rating at or below about 6°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 & scramblingBetaModerate thunderstorm risk. Avoid exposed rock if storms develop. Wet rock is likely. Gusts near 35 mph may affect balance on exposed rock. 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 Siltstone (Nant Ffrancon Subgroup). Often positive when dry, but smooth, polished or slabby sections can become markedly more slippery when damp. Gusts may reach about 35 mph. Crosswinds can make exposed ridges substantially more serious. Moderate thunderstorm risk, broadly during the morning. Avoid committing to exposed ground if storms develop.
Often positive when dry, but smooth, polished or slabby sections can become markedly more slippery when damp. 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, but cloud could hide it 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, but cloud could hide it
Forecast activity gives only a small prospect here, most likely a faint glow picked up by a camera. Forecast activity peaks near Kp 5.3 on the 0 to 9 scale.
Look north-north-west, from the horizon part-way up the sky. A clear, open view that way matters more than height.
The Moon is below the horizon around the best forecast hour, so moonlight should not wash out a faint display then.
Aurora viewing guidance
Cloud is sampled overhead and towards the northern viewing horizon. Narrow cloud bands can still be missed. The available models broadly agree 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.
More surrounding artificial light lies towards the aurora than at most assessed peaks. This may make a faint, low display harder to pick out.
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
Poor sky conditions during the best available spell: 24 Sep, 04:00 BST to 05:00 BST.
Cloud is likely to obscure much of the sky.
Moon-free dark sky: 24 Sep, 04:00 BST to 05:05 BST.
Sky conditions through the night
| Time | Viewing conditions |
|---|---|
| 23 Sep, 21:10 BST to 22:00 BST | Poor sky conditions Clearer spells are possible, but other forecasts keep much of the sky obscured by cloud. Forecast models disagree. |
| 23 Sep, 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 Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars. |
| 24 Sep, 01:00 BST to 02:00 BST | Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars. |
| 24 Sep, 02:00 BST to 03:00 BST | Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars. |
| 24 Sep, 03:00 BST to 04:00 BST | Poor sky conditions Cloud is likely to obscure much of the sky. |
| 24 Sep, 04:00 BST to 05:00 BST | Poor sky conditions Cloud is likely to obscure much of the sky. |
| 24 Sep, 05:00 BST to 05:05 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, 18:10 BST.
Moonset around 24 Sep, 04:00 BST.
Full darkness: 23 Sep, 21:10 BST to 24 Sep, 05:05 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 780 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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