The day on the hill
Little rain and limited summit cloud on Blorenge: summit wind broadly 5-15 mph, with gusts 10-20 mph at times (light winds).
Cloud & views
Cloud base around 800–1100 m in the morning, then around 700–1000 m around midday and 900–1200 m by late afternoon. 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.
Cloud-free timing: Best later at about 85%. Lowest around midday at about 75%.
Sunshine context Model-grid estimate, not summit sunshine
The surrounding model grid indicates 9.9 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
- 2.2 h
- Midday
- 4 h
- Later
- 1.6 h
Overnight forecast: 17:00–08:00 (UK local time), in Wild camping below.
Overnight · 17:00–08:00Wild campingBetaCondensation risk is high near 300 and 600 m. 64/100Mixed · 600 m View detailsHide details
Full overnight outlook
Open-hillside camping looks reasonable overall around 600 m (64/100). Light winds are expected on open ground, though local shelter and exposure still matter. Little overnight rain is forecast. 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
- 78%
- Moonrise
- 17:29 BST
- Moonset
- 01:33 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: 21 Sep, 17:00 BST to 22 Sep, 08:00 BST. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.
Elevation reference (open ground)
- Wind / gust
- 4 mph / 8 mph
- Typical / low
- 13.3°C / 12.0°C
- In cloud
- 0% of modelled night
- Condensation
- High
- Wind / gust
- 5 mph / 9 mph
- Typical / low
- 13.6°C / 12.3°C
- In cloud
- 20% 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 10°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 Sandstone (South Wales Lower Coal Measures Formation). Usually rough and grippy when dry. Damp sandstone and gritstone can feel greasy, and saturated sandstone may be weakened, so let the rock dry fully.
Often grippy when dry, but wet sandstone can lose strength and may be damaged by climbing. Avoid it while saturated and allow shaded walls, pockets and seepage lines time to dry. 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.
Popular Blorenge
sandstone or gritstone
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 breaks may offer some views of the stars. View forecastClose forecast
After dark: aurora and stargazing
Night beginning 2026-09-21. All times are UK local time.
Stargazing
Good sky conditions during the best available spell: 22 Sep, 00:00 BST to 01:00 BST.
Cloud breaks may offer some views of the stars.
Moon-free dark sky: 22 Sep, 01:25 BST to 05:05 BST.
Sky conditions through the night
| Time | Viewing conditions |
|---|---|
| 21 Sep, 21:10 BST to 22:00 BST | Mixed sky conditions Clearer spells are possible, but other forecasts keep much of the sky obscured by cloud. Forecast models disagree. |
| 21 Sep, 22:00 BST to 23:00 BST | Mixed sky conditions Cloud breaks may offer some views of the stars. Moonlight washes out fainter stars. |
| 21 Sep, 23:00 BST to 22 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. |
| 22 Sep, 00:00 BST to 01:00 BST | Good sky conditions Cloud breaks may offer some views of the stars. |
| 22 Sep, 01:00 BST to 02:00 BST | Mixed sky conditions Cloud breaks may offer some views of the stars. Reduced visibility may obscure faint objects. |
| 22 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. |
| 22 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. |
| 22 Sep, 04:00 BST to 05:00 BST | Poor sky conditions Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects. |
| 22 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 78% illuminated.
Moonrise around 21 Sep, 17:30 BST.
Moonset around 22 Sep, 01:25 BST.
Full darkness: 21 Sep, 21:10 BST to 22 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 955 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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