Pen y Fan Weather Forecast – 886m, Bannau Brycheiniog (Brecon Beacons)

Thursday 3 September 2026Medium confidence

Overall hill weather54/100Mixed

Wind29 mph W Gusts41 mph Feels9°C Rain0.1 mm Cloud-free summit25% Cloud base through day500–1,100 m Freezing levelAbove summit Daylight06:28–19:57 · 13.5 h

Forecast confidence: Cloud height is close to summit level at times, so small local changes could put the top in or out of cloud.

A grey, cloudy day on Pen y Fan: summit wind broadly 20-35 mph, with gusts 35-45 mph during the evening (gale-force winds). The ground is likely to be wet after recent rain. Much calmer lower down - generally 10-20 mph in the valley, rising towards the tops. Cloud base around 800-1100 m in the morning, lowering to 500-800 m around midday. Expect the top to stay in cloud for most or all of daylight, with no dependable break. Cloud height is close to summit level at times, so small local changes could put the top in or out of cloud. Cloud is likely to hang lowest on western slopes; the eastern side should see somewhat higher bases and better breaks. Sunshine is likely to be limited to about 2 hours through breaks in the cloud. Little or no rain expected. Cloud base is the least certain part of this - it could sit a couple of hundred metres either way, especially where it is close to summit level.

At this mountain

Sunshine and sky

Limited sunny breaks. Any sunshine is likely to come through limited breaks.

Modelled sunshine1.7 h13% of daylight

Early0 h sunshine

MiddayLess than 1 hour sunshine

LaterLess than 1 hour sunshine

These are direct modelled sunshine hours during daylight, not the probability of sunshine. Cloud cover and summit cloud are assessed separately in the forecast above. Local hill cloud can still make an individual summit brighter or duller than the surrounding model grid.

Morning · 07:00–13:00Mixed

56/100

Afternoon & evening · 13:00–22:00Mixed

51/100

Separate hill-weather grades help compare an early start with later conditions; the main daytime forecast above still covers the core walking day.

Overnight · 6 p.m.–9 a.m.Wild campingBetaGusts near 65 mph make meaningful shelter important. 39/100Poor · 600 m View detailsHide details

Night beginning Thursday 3 September 2026

Full overnight outlook

Open-hillside camping looks poor overall around 600 m (39/100). A lower pitch near 300 m looks more comfortable; conditions are less suitable by 900 m. Open-ground gusts may reach about 65 mph, making exposed pitches a poor choice. Peak gusts increase from about 45 mph at 300 m to 65 mph at 900 m. A wet night is likely, with roughly 14.8 mm and rain liable to affect both pitching and packing up. From around 900 m upward, pitches may spend part of the night in cloud, with high condensation risk, persistent damp and poor visibility; ventilation will matter. The coldest temperature falls from about 11.6°C at 300 m to 9.3°C at 900 m.

Overnight rain15 mm Open ground · 600 m30 mph · gusts 53 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 8°C or lower

Elevation reference (open ground)

300 m39/100 · poor

Wind / gust: 25 / 44 mph
Typical / low: 14.7° / 11.6°C
In cloud: Unlikely
Condensation: High

600 m39/100 · poor

Wind / gust: 30 / 53 mph
Typical / low: 14.4° / 11.2°C
In cloud: 19% of night
Condensation: High

900 m24/100 · poor

Wind / gust: 36 / 63 mph
Typical / low: 12.6° / 9.3°C · a brief spell
In cloud: 100% of 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 & scramblingBetaGusts near 40 mph increase the seriousness of exposed ground. 30/100Poor · Poor View detailsHide details

Generic exposed-rock guidance

Full climbing & scrambling outlook

Conditions for exposed scrambling look poor (30/100). Some rock may still be damp or drying; polished slabs and vegetated sections could be notably worse. The mapped summit rock is Interbedded sandstone and [subequal/subordinate] argillaceous rocks (Brownstones 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. Gusts may reach about 40 mph; crosswinds can make exposed ridges substantially more serious. Cloud may also make route-finding and retreat harder.

Rock surfaceDamp or dryingPeak gust41 mphRain0.0 mm

Main factorsgusts around 40 mphdamp or incompletely dried rock possiblemuch of the route may be in cloud

Mapped rock across the summit and available routes Interbedded sandstone and [subequal/subordinate] argillaceous rocks Brownstones Formation

Origin: Sedimentary
Rock family: Sandstone or gritstone
Mapping: BGS Geology 50K · 1:50,000
Rock-response profile: High confidence

View the summit BGS record

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. 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.

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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Friday 4 September 2026Medium confidence

Overall hill weather57/100Mixed

Wind31 mph W Gusts44 mph Feels5°C Rain3.6 mm Cloud-free summit55% Cloud base through day800–1,800 m Freezing levelAbove summit Daylight06:29–19:54 · 13.4 h

Forecast confidence: Forecast models disagree materially on rainfall amounts.

Spate watch

Burns and unbridged crossings may rise quickly. Assess them at the water and turn back if unsure.

Cloud-free timing: Around 25% early, improving to around 65% later.

A mixed day on Pen y Fan: summit wind broadly 20-35 mph, with gusts 40-50 mph during the morning (gale-force winds). There could be a spate risk based on forecast rainfall. Burns and unbridged crossings may rise quickly. Most likely from around 00:00 until around 13:00. Much calmer lower down - generally 10-20 mph in the valley, rising towards the tops. Cloud base around 800–1100 m in the morning, lifting to 1500–1800 m around midday and 1400–1700 m by late afternoon. Summit cloud should lift later, bringing a better chance of clear views. Cloud height is close to summit level at times, so small local changes could put the top in or out of cloud. Cloud is likely to hang lowest on western slopes; the eastern side should see somewhat higher bases and better breaks. about 6 hours of sunshine is indicated, with variable cloud giving brighter and duller spells. Some rain is likely, with around 2-5 mm indicated; timing and local totals remain uncertain. Cloud base is the least certain part of this - it could sit a couple of hundred metres either way, especially where it is close to summit level.

At this mountain

Sunshine and sky

Brighter and duller spells. Expect alternating brighter and duller spells.

Modelled sunshine6.2 h48% of daylight

Early0 h sunshine

Midday4 h sunshine

Later1.2 h sunshine

These are direct modelled sunshine hours during daylight, not the probability of sunshine. Cloud cover and summit cloud are assessed separately in the forecast above. Local hill cloud can still make an individual summit brighter or duller than the surrounding model grid.

Morning · 07:00–13:00Poor

30/100

Afternoon & evening · 13:00–22:00Good

84/100

Separate hill-weather grades help compare an early start with later conditions; the main daytime forecast above still covers the core walking day.

Overnight · 6 p.m.–9 a.m.Wild campingBetaGusts near 40 mph make meaningful shelter important. 86/100Excellent · 600 m View detailsHide details

Night beginning Friday 4 September 2026

Full overnight outlook

Open-hillside camping looks promising overall around 600 m (86/100). A lower pitch near 300 m looks more comfortable; conditions are less suitable by 900 m. Open-ground gusts may reach about 40 mph; seek meaningful shelter. Peak gusts increase from about 25 mph at 300 m to 40 mph at 900 m. Little overnight rain is expected. From around 900 m upward, pitches may spend part of the night in cloud, bringing persistent damp and poor visibility. The coldest temperature falls from about 9.1°C at 300 m to 7.1°C at 900 m.

Overnight rain0.0 mm Open ground · 600 m18 mph · gusts 32 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 6°C or lower

Elevation reference (open ground)

300 m89/100 · very good

Wind / gust: 15 / 27 mph
Typical / low: 10.2° / 9.1°C · several hours
In cloud: Unlikely
Condensation: Low

600 m86/100 · promising

Wind / gust: 18 / 32 mph
Typical / low: 10.2° / 9.1°C · several hours
In cloud: Unlikely
Condensation: Low

900 m76/100 · promising

Wind / gust: 22 / 38 mph
Typical / low: 8.1° / 7.1°C · much of the night
In cloud: 31% of 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 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 & scramblingBetaGusts near 45 mph increase the seriousness of exposed ground. 0/100Poor · Very poor View detailsHide details

Generic exposed-rock guidance

Full climbing & scrambling outlook

Conditions for exposed scrambling look very poor (0/100). Rain during the useful part of the day is likely to leave rock wet and more slippery. The mapped summit rock is Interbedded sandstone and [subequal/subordinate] argillaceous rocks (Brownstones 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. Gusts may reach about 45 mph; crosswinds can make exposed ridges substantially more serious.

Rock surfaceWet rock likelyPeak gust44 mphRain1.6 mm

Main factorsgusts around 45 mphwet rock likely

Mapped rock across the summit and available routes Interbedded sandstone and [subequal/subordinate] argillaceous rocks Brownstones Formation

Origin: Sedimentary
Rock family: Sandstone or gritstone
Mapping: BGS Geology 50K · 1:50,000
Rock-response profile: High confidence

View the summit BGS record

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. 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.

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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Saturday 5 September 2026Medium confidence

Overall hill weather90/100Excellent

Wind19 mph W Gusts26 mph Feels3°C Rain0.0 mm Cloud-free summit60% Cloud base through day800–2,000 m Freezing levelAbove summit Daylight06:31–19:52 · 13.3 h

Forecast confidence: Cloud height is close to summit level at times, so small local changes could put the top in or out of cloud.

Cloud-free timing: Best around midday at about 70%; around 45% early and 50% later.

A mixed day on Pen y Fan: summit wind broadly 5-25 mph, with gusts 20-30 mph early in the morning (fresh and blowy). The ground is likely to be wet after recent rain. Cloud base around 800–1100 m in the morning, then around 1700–2000 m around midday and 1000–1300 m by late afternoon. The top is likely to drift in and out of cloud; views may come and go. Cloud height is close to summit level at times, so small local changes could put the top in or out of cloud. A generally bright day is indicated, with about 12 hours of sunshine. Little or no rain expected. Cloud base is the least certain part of this - it could sit a couple of hundred metres either way, especially where it is close to summit level.

At this mountain

Sunshine and sky

Generally bright. A generally bright day is indicated.

Modelled sunshine11.8 h91% of daylight

Early2 h sunshine

Midday3.9 h sunshine

Later3.9 h sunshine

These are direct modelled sunshine hours during daylight, not the probability of sunshine. Cloud cover and summit cloud are assessed separately in the forecast above. Local hill cloud can still make an individual summit brighter or duller than the surrounding model grid.

Morning · 07:00–13:00Excellent

88/100

Afternoon & evening · 13:00–22:00Excellent

91/100

Separate hill-weather grades help compare an early start with later conditions; the main daytime forecast above still covers the core walking day.

Overnight · 6 p.m.–9 a.m.Wild campingBetaGusts near 40 mph make meaningful shelter important. 84/100Good · 600 m View detailsHide details

Night beginning Saturday 5 September 2026

Full overnight outlook

Open-hillside camping looks promising overall around 600 m (84/100). A lower pitch near 300 m looks more comfortable; conditions are less suitable by 900 m. Open-ground gusts may reach about 40 mph; seek meaningful shelter. Peak gusts increase from about 25 mph at 300 m to 40 mph at 900 m. Wind may shift from westerly to southerly; shelter that works at dusk may be less effective later. Little overnight rain is expected. The coldest temperature falls from about 11.5°C at 300 m to 7.3°C at 900 m.

Overnight rain0.0 mm Open ground · 600 m13 mph · gusts 35 mph Morning pack-upNo wet signal Sleeping-bag warmthISO comfort rating about 8°C or lower

Elevation reference (open ground)

300 m89/100 · very good

Wind / gust: 11 / 26 mph
Typical / low: 12.4° / 11.5°C
In cloud: Unlikely
Condensation: Low

600 m84/100 · promising

Wind / gust: 13 / 35 mph
Typical / low: 12.4° / 11.7°C
In cloud: 12% of night
Condensation: Low

900 m75/100 · promising

Wind / gust: 17 / 42 mph
Typical / low: 9.7° / 7.3°C · much of the night
In cloud: 12% of night
Condensation: Low

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 may be damp or still drying after recent rain. 70/100Good · Fair View detailsHide details

Generic exposed-rock guidance

Full climbing & scrambling outlook

Conditions for exposed scrambling look fair (70/100). Some rock may still be damp or drying; polished slabs and vegetated sections could be notably worse. The mapped summit rock is Interbedded sandstone and [subequal/subordinate] argillaceous rocks (Brownstones 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.

Rock surfaceDamp or dryingPeak gust21 mphRain0.0 mm

Main concerndamp or incompletely dried rock possible

Mapped rock across the summit and available routes Interbedded sandstone and [subequal/subordinate] argillaceous rocks Brownstones Formation

Origin: Sedimentary
Rock family: Sandstone or gritstone
Mapping: BGS Geology 50K · 1:50,000
Rock-response profile: High confidence

View the summit BGS record

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. 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.

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.

Did this match your experience?Tell us about the rock surface and wind to help improve this beta forecast.Give feedback

Sunday 6 September 2026Medium confidence

Overall hill weather80/100Good

Wind30 mph SW Gusts42 mph Feels6°C Rain0.0 mm Cloud-free summit70% Cloud base through day500–1,900 m Freezing levelAbove summit Daylight06:33–19:50 · 13.3 h

Forecast confidence: Forecast models disagree on cloud height and timing.

Cloud-free timing: Around 80% early, falling to around 50% later.

A mixed day on Pen y Fan: summit wind broadly 20-35 mph, with gusts 35-45 mph during the morning (gale-force winds). Much calmer lower down - generally 10-20 mph in the valley, rising towards the tops. Cloud height is close to summit level at times, so small local changes could put the top in or out of cloud. A generally bright day is indicated, with about 12 hours of sunshine. Little or no rain expected. Confidence moderate (Summit wind could be roughly 23-38 mph, which changes how difficult exposed walking may feel) - walker-height summit wind could reasonably be 23-38 mph, with gusts 32-53 mph. Cloud base is the least certain part of this - it could sit a couple of hundred metres either way, especially where it is close to summit level.

At this mountain

Sunshine and sky

Generally bright. A generally bright day is indicated.

Modelled sunshine12 h93% of daylight

Early2 h sunshine

Midday4 h sunshine

Later4 h sunshine

These are direct modelled sunshine hours during daylight, not the probability of sunshine. Cloud cover and summit cloud are assessed separately in the forecast above. Local hill cloud can still make an individual summit brighter or duller than the surrounding model grid.

Morning · 07:00–13:00Excellent

86/100

Afternoon & evening · 13:00–22:00Good

74/100

Separate hill-weather grades help compare an early start with later conditions; the main daytime forecast above still covers the core walking day.

Overnight · 6 p.m.–9 a.m.Wild campingBetaGusts near 40 mph make meaningful shelter important. 54/100Mixed · 600 m View detailsHide details

Night beginning Sunday 6 September 2026

Full overnight outlook

Open-hillside camping looks mixed overall around 600 m (54/100). Open-ground gusts may reach about 40 mph; seek meaningful shelter. Peak gusts increase from about 25 mph at 300 m to 40 mph at 900 m. Around 1.2 mm is forecast, with a damp or wet pitch most likely. From around 600 m upward, pitches may spend part of the night in cloud, with high condensation risk, persistent damp and poor visibility; ventilation will matter. The coldest temperature falls from about 9.8°C at 300 m to 7.2°C at 900 m.

Overnight rain1.2 mm Open ground · 600 m19 mph · gusts 33 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 6°C or lower

Elevation reference (open ground)

300 m64/100 · reasonable

Wind / gust: 16 / 27 mph
Typical / low: 14.0° / 9.8°C · a brief spell
In cloud: Unlikely
Condensation: High

600 m54/100 · mixed

Wind / gust: 19 / 33 mph
Typical / low: 13.7° / 9.8°C · several hours
In cloud: 88% of night
Condensation: High

900 m54/100 · mixed

Wind / gust: 22 / 39 mph
Typical / low: 12.1° / 7.2°C · several hours
In cloud: 88% of 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 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.

Did this match your night?Share a quick observation to help improve this beta forecast.Give feedback

Daytime · exposed rockClimbing & scramblingBetaGusts near 40 mph increase the seriousness of exposed ground. 34/100Poor · Poor View detailsHide details

Generic exposed-rock guidance

Full climbing & scrambling outlook

Conditions for exposed scrambling look poor (34/100). It may be dry overhead, but recent rain leaves uncertainty around seepage and shaded sections. The mapped summit rock is Interbedded sandstone and [subequal/subordinate] argillaceous rocks (Brownstones 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. Gusts may reach about 40 mph; crosswinds can make exposed ridges substantially more serious.

Rock surfaceDry overhead; seepage uncertainPeak gust42 mphRain0.0 mm

Main factorsgusts around 40 mphdamp or incompletely dried rock possible

Mapped rock across the summit and available routes Interbedded sandstone and [subequal/subordinate] argillaceous rocks Brownstones Formation

Origin: Sedimentary
Rock family: Sandstone or gritstone
Mapping: BGS Geology 50K · 1:50,000
Rock-response profile: High confidence

View the summit BGS record

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. 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.

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.

Did this match your experience?Tell us about the rock surface and wind to help improve this beta forecast.Give feedback

Monday 7 September 2026Medium confidence

Overall hill weather68/100Mixed

Wind26 mph W Gusts37 mph Feels3°C Rain0.0 mm Cloud-free summit55% Cloud base through day500–1,900 m Freezing levelAbove summit Daylight06:34–19:47 · 13.2 h

Forecast confidence: Cloud height is close to summit level at times, so small local changes could put the top in or out of cloud.

Cloud-free timing: Best around midday at about 65%; around 40% early and 45% later.

A mixed day on Pen y Fan: summit wind broadly 15-30 mph, with gusts 30-40 mph during the evening (strong winds). Much calmer lower down - generally 5-15 mph in the valley, rising towards the tops. Cloud base around 500–800 m in the morning, then around 1600–1900 m around midday and 1000–1300 m by late afternoon. The top is likely to drift in and out of cloud; views may come and go. Cloud height is close to summit level at times, so small local changes could put the top in or out of cloud. about 5 hours of sunshine is indicated, with variable cloud giving brighter and duller spells. Little or no rain expected. Confidence moderate (forecast models agree on the walking impact of the wind) - walker-height summit wind could reasonably be 21-30 mph, with gusts 29-42 mph. Cloud base is the least certain part of this - it could sit a couple of hundred metres either way, especially where it is close to summit level.

At this mountain

Sunshine and sky

Brighter and duller spells. Expect alternating brighter and duller spells.

Modelled sunshine4.7 h36% of daylight

Early1.1 h sunshine

Midday2.6 h sunshine

LaterLess than 1 hour sunshine

These are direct modelled sunshine hours during daylight, not the probability of sunshine. Cloud cover and summit cloud are assessed separately in the forecast above. Local hill cloud can still make an individual summit brighter or duller than the surrounding model grid.

Morning · 07:00–13:00Mixed

69/100

Afternoon & evening · 13:00–22:00Mixed

67/100

Separate hill-weather grades help compare an early start with later conditions; the main daytime forecast above still covers the core walking day.

Overnight · 6 p.m.–9 a.m.Wild campingBetaGusts near 50 mph make meaningful shelter important. 54/100Mixed · 600 m View detailsHide details

Night beginning Monday 7 September 2026

Full overnight outlook

Open-hillside camping looks mixed overall around 600 m (54/100). A lower pitch near 300 m looks more comfortable; conditions are less suitable by 900 m. Open-ground gusts may reach about 50 mph, making exposed pitches a poor choice. Peak gusts increase from about 35 mph at 300 m to 50 mph at 900 m. Around 4.5 mm is forecast, with a damp or wet pitch most likely. From around 600 m upward, pitches may spend part of the night in cloud, with high condensation risk, persistent damp and poor visibility; ventilation will matter. The coldest temperature falls from about 8°C at 300 m to 5.6°C at 900 m.

Overnight rain4.5 mm Open ground · 600 m28 mph · gusts 42 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 4°C or lower

Elevation reference (open ground)

300 m66/100 · reasonable

Wind / gust: 23 / 35 mph
Typical / low: 11.6° / 8.0°C · several hours
In cloud: Unlikely
Condensation: Moderate

600 m54/100 · mixed

Wind / gust: 28 / 42 mph
Typical / low: 11.3° / 7.7°C · several hours
In cloud: 62% of night
Condensation: High

900 m39/100 · poor

Wind / gust: 32 / 50 mph
Typical / low: 9.3° / 5.6°C · much of the night
In cloud: 75% of 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 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.

Did this match your night?Share a quick observation to help improve this beta forecast.Give feedback

Daytime · exposed rockClimbing & scramblingBetaGusts near 35 mph increase the seriousness of exposed ground. 70/100Good · Fair View detailsHide details

Generic exposed-rock guidance

Full climbing & scrambling outlook

Conditions for exposed scrambling look fair (70/100). It is likely to stay mostly dry, but some forecast models allow patchy rain or drizzle; exposed rock may therefore become damp or slippery. The mapped summit rock is Interbedded sandstone and [subequal/subordinate] argillaceous rocks (Brownstones 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. Gusts may reach about 35 mph; crosswinds can make exposed ridges substantially more serious.

Rock surfaceDry initially; rain possiblePeak gust34 mphRainPossible · 42%

Main factorsgusts around 35 mphrain possible despite mostly dry conditions being favoured

Mapped rock across the summit and available routes Interbedded sandstone and [subequal/subordinate] argillaceous rocks Brownstones Formation

Origin: Sedimentary
Rock family: Sandstone or gritstone
Mapping: BGS Geology 50K · 1:50,000
Rock-response profile: High confidence

View the summit BGS record

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. 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.

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.

Did this match your experience?Tell us about the rock surface and wind to help improve this beta forecast.Give feedback

Tuesday 8 September 2026Medium confidence

Overall hill weather60/100Mixed

Wind34 mph W Gusts48 mph Feels-1°C Rain0.0 mm Cloud-free summit70% Freezing levelAbove summit Daylight06:36–19:45 · 13.2 h

Forecast confidence: Forecast models differ on whether meaningful rain reaches the hills during the main walking period.

A wild day on Pen y Fan: summit wind broadly 20-40 mph, with gusts 45-55 mph early in the morning (gale-force winds). Much calmer lower down - generally 10-20 mph in the valley, rising towards the tops. Any cloud sits well above the tops (base 1400-2000 m) - clear summits. Cloud is likely to hang lowest on western slopes; the eastern side should see somewhat higher bases and better breaks. Very little direct sunshine is indicated; cloud is likely to remain extensive. Little or no rain expected. Cold on top: air temperature broadly 4 to 8°C, feeling around -2 to 2°C in the wind - wrap up. Confidence moderate (Summit wind could be roughly 30-43 mph, which changes how difficult exposed walking may feel) - walker-height summit wind could reasonably be 30-43 mph, with gusts 42-61 mph. Cloud base is the least certain part of this - it could sit a couple of hundred metres either way, especially where it is close to summit level.

At this mountain

Sunshine and sky

Extensive cloud. Cloud is likely to remain extensive for much of the day.

Modelled sunshine0 h0% of daylight

Early0 h sunshine

Midday0 h sunshine

Later0 h sunshine

These are direct modelled sunshine hours during daylight, not the probability of sunshine. Cloud cover and summit cloud are assessed separately in the forecast above. Local hill cloud can still make an individual summit brighter or duller than the surrounding model grid.

Morning · 07:00–13:00Mixed

57/100

Afternoon & evening · 13:00–22:00Mixed

64/100

Separate hill-weather grades help compare an early start with later conditions; the main daytime forecast above still covers the core walking day.

Overnight · 6 p.m.–9 a.m.Wild campingBetaGusts near 40 mph make meaningful shelter important. 82/100Good · 600 m View detailsHide details

Night beginning Tuesday 8 September 2026

Full overnight outlook

Open-hillside camping looks promising overall around 600 m (82/100). Open-ground gusts may reach about 40 mph; seek meaningful shelter. Peak gusts increase from about 30 mph at 300 m to 40 mph at 900 m. Little overnight rain is expected. The coldest temperature falls from about 7.4°C at 300 m to 4.7°C at 900 m.

Overnight rain0.0 mm Open ground · 600 m22 mph · gusts 34 mph Morning pack-upNo wet signal Sleeping-bag warmthISO comfort rating about 4°C or lower

Elevation reference (open ground)

300 m82/100 · promising

Wind / gust: 19 / 28 mph
Typical / low: 9.0° / 7.4°C · much of the night
In cloud: Unlikely
Condensation: Low

600 m82/100 · promising

Wind / gust: 22 / 34 mph
Typical / low: 8.7° / 7.2°C · much of the night
In cloud: Unlikely
Condensation: Low

900 m72/100 · reasonable

Wind / gust: 26 / 40 mph
Typical / low: 6.2° / 4.7°C · a brief spell
In cloud: Unlikely
Condensation: Low

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 & scramblingBetaGusts near 45 mph increase the seriousness of exposed ground. 14/100Poor · Very poor View detailsHide details

Generic exposed-rock guidance

Full climbing & scrambling outlook

Conditions for exposed scrambling look very poor (14/100). It is likely to stay mostly dry, but some forecast models allow patchy rain or drizzle; exposed rock may therefore become damp or slippery. The mapped summit rock is Interbedded sandstone and [subequal/subordinate] argillaceous rocks (Brownstones 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. Gusts may reach about 45 mph; crosswinds can make exposed ridges substantially more serious.

Rock surfaceDry initially; rain possiblePeak gust45 mphRainPossible · 70%

Main factorsgusts around 45 mphrain possible despite mostly dry conditions being favoured

Mapped rock across the summit and available routes Interbedded sandstone and [subequal/subordinate] argillaceous rocks Brownstones Formation

Origin: Sedimentary
Rock family: Sandstone or gritstone
Mapping: BGS Geology 50K · 1:50,000
Rock-response profile: High confidence

View the summit BGS record

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. 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.

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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Wednesday 9 September 2026Medium confidence

Overall hill weather74/100Good

Wind25 mph W Gusts35 mph Feels-1°C Rain0.0 mm Cloud-free summit60% Freezing levelAbove summit Daylight06:37–19:43 · 13.1 h

Forecast confidence: Rain could reach the main walking period or hold off until later; forecast models disagree on the timing.

A mixed day on Pen y Fan: summit wind broadly 15-30 mph, with gusts 30-40 mph early in the morning (strong winds). Much calmer lower down - generally 5-15 mph in the valley, rising towards the tops. Any cloud sits well above the tops (base 1300-1600 m) - clear summits. Cloud is likely to hang lowest on western slopes; the eastern side should see somewhat higher bases and better breaks. A generally bright day is indicated, with about 12 hours of sunshine. Little or no rain expected. Cold on top: air temperature broadly 2 to 6°C, feeling around -2 to 2°C in the wind - wrap up. Confidence moderate (Summit wind could be roughly 17-33 mph, which changes how difficult exposed walking may feel) - walker-height summit wind could reasonably be 17-33 mph, with gusts 24-47 mph. Cloud base is the least certain part of this - it could sit a couple of hundred metres either way, especially where it is close to summit level.

At this mountain

Sunshine and sky

Generally bright. A generally bright day is indicated.

Modelled sunshine12 h92% of daylight

Early2 h sunshine

Midday4 h sunshine

Later4 h sunshine

These are direct modelled sunshine hours during daylight, not the probability of sunshine. Cloud cover and summit cloud are assessed separately in the forecast above. Local hill cloud can still make an individual summit brighter or duller than the surrounding model grid.

Morning · 07:00–13:00Good

76/100

Afternoon & evening · 13:00–22:00Good

71/100

Separate hill-weather grades help compare an early start with later conditions; the main daytime forecast above still covers the core walking day.

Overnight · 6 p.m.–9 a.m.Wild campingBetaGusts near 35 mph make meaningful shelter important. 64/100Mixed · 600 m View detailsHide details

Night beginning Wednesday 9 September 2026

Full overnight outlook

Open-hillside camping looks reasonable overall around 600 m (64/100). Open-ground gusts may reach about 35 mph; seek meaningful shelter. Peak gusts increase from about 25 mph at 300 m to 35 mph at 900 m. Little overnight rain is expected. From around 900 m upward, pitches may spend part of the night in cloud, with high condensation risk, persistent damp and poor visibility; ventilation will matter. The coldest temperature falls from about 8°C at 300 m to 6°C at 900 m.

Overnight rain0.0 mm Open ground · 600 m16 mph · gusts 29 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 6°C or lower

Elevation reference (open ground)

300 m64/100 · reasonable

Wind / gust: 13 / 24 mph
Typical / low: 9.8° / 8.0°C · much of the night
In cloud: Unlikely
Condensation: High

600 m64/100 · reasonable

Wind / gust: 16 / 29 mph
Typical / low: 9.1° / 8.0°C · much of the night
In cloud: 19% of night
Condensation: High

900 m54/100 · mixed

Wind / gust: 19 / 34 mph
Typical / low: 7.2° / 6.0°C · much of the night
In cloud: 81% of 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 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 & scramblingBetaGusts near 35 mph increase the seriousness of exposed ground. 62/100Mixed · Fair View detailsHide details

Generic exposed-rock guidance

Full climbing & scrambling outlook

Conditions for exposed scrambling look fair (62/100). Some rock may still be damp or drying; polished slabs and vegetated sections could be notably worse. The mapped summit rock is Interbedded sandstone and [subequal/subordinate] argillaceous rocks (Brownstones 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. Gusts may reach about 35 mph; crosswinds can make exposed ridges substantially more serious.

Rock surfaceDamp or dryingPeak gust34 mphRain0.0 mm

Main factorsgusts around 35 mphdamp or incompletely dried rock possible

Mapped rock across the summit and available routes Interbedded sandstone and [subequal/subordinate] argillaceous rocks Brownstones Formation

Origin: Sedimentary
Rock family: Sandstone or gritstone
Mapping: BGS Geology 50K · 1:50,000
Rock-response profile: High confidence

View the summit BGS record

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. 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.

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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Pen y Fan weather forecast.

Today on Pen y Fan.

Seven-day Pen y Fan forecast.

Sunshine and sky

Full overnight outlook

Elevation reference (open ground)

Full climbing & scrambling outlook

Sunshine and sky

Full overnight outlook

Elevation reference (open ground)

Full climbing & scrambling outlook

Sunshine and sky

Full overnight outlook

Elevation reference (open ground)

Full climbing & scrambling outlook

Sunshine and sky

Full overnight outlook

Elevation reference (open ground)

Full climbing & scrambling outlook

Sunshine and sky

Full overnight outlook

Elevation reference (open ground)

Full climbing & scrambling outlook

Sunshine and sky

Full overnight outlook

Elevation reference (open ground)

Full climbing & scrambling outlook

Sunshine and sky

Full overnight outlook

Elevation reference (open ground)

Full climbing & scrambling outlook

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Pen y Fan weather forecast.

Today on Pen y Fan.

Seven-day Pen y Fan forecast.

Full overnight outlook

Elevation reference (open ground)

Full climbing & scrambling outlook

Full overnight outlook

Elevation reference (open ground)

Full climbing & scrambling outlook

Full overnight outlook

Elevation reference (open ground)

Full climbing & scrambling outlook

Full overnight outlook

Elevation reference (open ground)

Full climbing & scrambling outlook

Full overnight outlook

Elevation reference (open ground)

Full climbing & scrambling outlook

Full overnight outlook

Elevation reference (open ground)

Full climbing & scrambling outlook

Full overnight outlook

Elevation reference (open ground)

Full climbing & scrambling outlook

Stay close to Pen y Fan.

Our cottage shortlist.

Brynich Villa

Gwrlodde

Marlais

Search exact availability.

Weather around Pen y Fan.

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