The day on the hill
Little rain and limited summit cloud on Moel y Cerrig Duon: summit wind broadly 0-15 mph, with gusts 5-15 mph at times (light winds). Patchy mist is possible in sheltered valleys early on.
Cloud & views
Cloud base mostly around 600–900 m through daylight. The summit is likely to stay mostly clear.
Cloud-height uncertainty could put the summit in or out of cloud. Clear spells may be difficult to time.
Rain & temperature
Little or no rain is forecast.
Forecast confidence
Cloud height remains uncertain, especially where it is close to summit level. Cloud-height uncertainty could put the summit in or out of cloud, even where forecasts agree on the wider cloud cover.
Sunshine context Model-grid estimate, not summit sunshine
The surrounding model grid indicates 6.6 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
- 1.7 h
- Midday
- 3.4 h
- Later
- 0.8 h
Overnight forecast: 17:00–08:00 (UK local time), in Wild camping below.
Overnight · 17:00–08:00Wild campingBetaAbout 3 mm is forecast, with rain possible around pack-up. 64/100Mixed · 600 m View detailsHide details
Full overnight outlook
Open-hillside camping looks reasonable overall around 600 m (64/100). It may be breezy on open ground, with gusts near 25 mph. Peak gusts range from about 20 mph at 300 m to 25 mph at 600 m. Around 3 mm is forecast, including rain around pack-up. Condensation risk is high near 300 and 600 m, so a wet pack-up is possible. Ventilation will matter.
Moon overnight
Waxing gibbous moon
- Illuminated disc
- 86%
- Moonrise
- 17:54 BST
- Moonset
- 02:48 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
- 11 mph / 22 mph
- Typical / low
- 12.8°C / 11.8°C
- In cloud
- 0% of modelled night
- Condensation
- High
- Wind / gust
- 13 mph / 27 mph
- Typical / low
- 12.8°C / 11.8°C
- In cloud
- 0% of modelled night
- Condensation
- High
Warmth planning: As a broad starting point, consider a 2-season bag with an ISO/EN comfort rating at or below about 8°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 is likely to be mostly dry, but check for local dampness. Excellent95/100 View detailsHide details
Full climbing & scrambling outlook
Conditions for exposed scrambling look excellent (95/100). Rock is likely to be mostly dry, though seepage and shaded holds are not resolved. The mapped summit rock is Siltstone and mudstone, interbedded (Moelfryn Mudstones Formation). Often positive when dry, but smooth, polished or slabby sections can become markedly more slippery when damp.
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 darkBetaCloud is likely to obscure much of the sky. Moonlight washes out fainter stars. View forecastClose forecast
After dark: aurora and stargazing
Night beginning 2026-09-22. All times are UK local time.
Aurora is unlikely on this night
Forecast activity is currently too weak for a likely sighting here. Forecast activity peaks near Kp 2.0 on the 0 to 9 scale. Roughly Kp 5.7 may bring a camera view near the northern horizon, but this is not a firm threshold.
Activity can change at short notice. Check again on the night.
Stargazing
Poor sky conditions during the best available spell: 22 Sep, 21:10 BST to 22:00 BST.
Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
Moon-free dark sky: 23 Sep, 02:40 BST to 05:05 BST.
Sky conditions through the night
| Time | Viewing conditions |
|---|---|
| 22 Sep, 21:10 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. Reduced visibility may obscure faint objects. 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. 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. 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. Reduced visibility may obscure faint objects. |
| 23 Sep, 02:00 BST to 03:00 BST | Poor sky conditions Cloud is likely to obscure much of the sky. 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. |
| 23 Sep, 04:00 BST to 05:00 BST | Poor sky conditions Cloud is likely to obscure much of the sky. Rain may interrupt viewing. |
| 23 Sep, 05:00 BST to 05:05 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 85% illuminated.
Moonrise around 22 Sep, 17:55 BST.
Moonset around 23 Sep, 02:40 BST.
Full darkness: 22 Sep, 21:10 BST to 23 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 482 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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