Mountain Weather

Fan Llia weather forecast.

632 m summit in Bannau Brycheiniog (Brecon Beacons). 8 forecast days covering wind, cloud, rain and temperature, updated 20 September 2026 at 16:08 UTC.

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Confidence: Medium
Overall hill weather84/100Good
Wind5-25 mph northwesterly Gusts25-35 mph Feels like4 to 8°C PrecipitationLittle or none Cloud-free summit estimate85% Cloud base through day600-1,700 m Freezing levelAbove summit DaylightSunrise 06:56 · Sunset 19:18 · 12.4 hours daylight

The day on the hill

Little rain and limited summit cloud on Fan Llia: summit wind broadly 5-25 mph, with gusts 25-35 mph at times (a fresh breeze). 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: Around 50% early, improving to around 95% later.

Sunshine context Model-grid estimate, not summit sunshine

The surrounding model grid indicates 7.4 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.

Morning · 08:00–12:00 Good Summit winds around 10-25 mph. Gusts around 25-35 mph are possible on exposed ground. Summit cloud is more persistent early in this period, with better prospects later.
79/100
Afternoon · 12:00–17:00 Excellent Summit winds around 5-15 mph. Gusts around 10-20 mph are possible on exposed ground.
90/100

Compare an early start with later conditions. The main forecast above covers the day in more detail.

Overnight · 17:00–08:00Wild campingBetaConditions look exceptional, but forecast uncertainty caps the grade at 97/100. 97/100Excellent · 600 m View detailsHide details
Night beginning Sunday 20 September 2026

Full overnight outlook

Open-hillside camping looks very good overall around 600 m (97/100). Light winds are expected on open ground, though local shelter and exposure still matter. Little overnight rain is forecast. Forecast models strongly support a good night, but not at the exceptional-certainty threshold. The grade is capped at 97/100.

Overnight rain0.0 mm Open ground · 600 m7 mph · gusts 13 mph Morning pack-upNo wet signal Sleeping-bag warmthISO comfort rating about 6°C or lower

Moon overnight

Waxing gibbous moon

Illuminated disc
70%
Moonrise
17:06 BST
Moonset
00:21 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: 20 Sep, 17:00 BST to 21 Sep, 08:00 BST. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.

Elevation reference (open ground)

300 m97/100 · very good
Wind / gust
6 mph / 11 mph
Typical / low
11.1°C / 9.8°C · a brief spell
In cloud
0% of modelled night
Condensation
Low
600 m97/100 · very good
Wind / gust
7 mph / 13 mph
Typical / low
11.1°C / 9.8°C · a brief spell
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.

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

Approximate height is enough, please do not share an exact wild-camp location.

Daytime · exposed rockClimbing & scramblingBetaRock is likely to be mostly dry, but check for local dampness. Excellent88/100 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Conditions for exposed scrambling look good (88/100). Rock is likely to be mostly dry, though seepage and shaded holds are not resolved. 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 surfaceProbably dryPeak gust28 mphRain0.0 mm
Mapped summit rock 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 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.

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

A broad surface report is enough; you do not need to identify a particular route.

Overnight · Aurora, stars & meteorsAfter darkBetaMostly clear skies are forecast. View forecastClose forecast

After dark: aurora and stargazing

Night beginning 2026-09-20. All times are UK local time.

Stargazing

Very good sky conditions during the best available spell: 20 Sep, 23:00 BST to 21 Sep, 00:00 BST.

Mostly clear skies are forecast.

Moon-free dark sky: 21 Sep, 00:15 BST to 05:05 BST.

Sky conditions through the night
Fully dark periods. Conditions can change between forecast hours.
TimeViewing conditions
20 Sep, 21:15 BST to 22:00 BSTGood sky conditions

Mostly clear skies are forecast.

20 Sep, 22:00 BST to 23:00 BSTGood sky conditions

Mostly clear skies are forecast.

20 Sep, 23:00 BST to 21 Sep, 00:00 BSTVery good sky conditions

Mostly clear skies are forecast.

21 Sep, 00:00 BST to 01:00 BSTMixed sky conditions

Clearer spells are possible, but other forecasts keep much of the sky obscured by cloud.

Forecast models disagree.

21 Sep, 01:00 BST to 02:00 BSTMixed sky conditions

Clearer spells are possible, but other forecasts keep much of the sky obscured by cloud.

Forecast models disagree.

21 Sep, 02:00 BST to 03:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky.

21 Sep, 03:00 BST to 04:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky.

21 Sep, 04:00 BST to 05:00 BSTMixed sky conditions

Clearer spells are possible, but other forecasts keep much of the sky obscured by cloud.

Forecast models disagree.

21 Sep, 05:00 BST to 05:05 BSTPoor sky conditions

Clearer spells are possible, but other forecasts keep much of the sky obscured by cloud.

Forecast models disagree.

Moon, darkness and meteor showers

Gibbous moon, about 69% illuminated.

Moonrise around 20 Sep, 17:10 BST.

Moonset around 21 Sep, 00:15 BST.

Full darkness: 20 Sep, 21:15 BST to 21 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 926 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.

Does the weather shape your plans?Optional hill-user research. One answer helps; further questions are up to you.Take part

Help the Mountain Decisions Project understand how forecasts influence hill days, including when plans stay the same. Findings will be shared publicly as summaries, not individual responses.

This is about Fan Llia on Sunday 20 September 2026. It asks about intentions, not whether you actually went out. No name or account is needed.

Open the questions to take part.

About the research and your privacy · Already been out? Share that experience instead

Confidence: Medium
Overall hill weather90/100Excellent
Wind0-15 mph northwesterly Gusts10-20 mph Feels like8 to 12°C PrecipitationLittle or none Cloud-free summit estimate80% Freezing levelAbove summit DaylightSunrise 06:57 · Sunset 19:15 · 12.3 hours daylight

The day on the hill

Little rain and limited summit cloud on Fan Llia: summit wind broadly 0-15 mph, with gusts 10-20 mph at times (light winds).

Cloud & views

Cloud base around 1600–1900 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: Around 95% early, falling to around 70% later.

Sunshine context Model-grid estimate, not summit sunshine

The surrounding model grid indicates 6.8 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
0 h

Overnight forecast: 17:00–08:00 (UK local time), in Wild camping below.

Morning · 08:00–12:00 Excellent Summit winds around 5-15 mph. Gusts around 10-20 mph are possible on exposed ground.
90/100
Afternoon · 12:00–17:00 Excellent Summit winds around 0-10 mph. Gusts around 5-15 mph are possible on exposed ground.
90/100

Compare an early start with later conditions. The main forecast above covers the day in more detail.

Overnight · 17:00–08:00Wild campingBetaA broadly very good night on a well-chosen pitch. 91/100Excellent · 600 m View detailsHide details
Night beginning Monday 21 September 2026

Full overnight outlook

Open-hillside camping looks very good overall around 600 m (91/100). Light winds are expected on open ground, though local shelter and exposure still matter. Little overnight rain is forecast. Some condensation is possible overnight.

Overnight rain0.0 mm Open ground · 600 m6 mph · gusts 11 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 10°C or lower

Moon overnight

Waxing gibbous moon

Illuminated disc
78%
Moonrise
17:31 BST
Moonset
01:35 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)

300 m91/100 · very good
Wind / gust
5 mph / 9 mph
Typical / low
13.4°C / 12.8°C
In cloud
0% of modelled night
Condensation
Moderate
600 m91/100 · very good
Wind / gust
6 mph / 11 mph
Typical / low
13.4°C / 12.8°C
In cloud
0% of modelled night
Condensation
Moderate

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.

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

Approximate height is enough, please do not share an exact wild-camp location.

Daytime · exposed rockClimbing & scramblingBetaRock is likely to be mostly dry, but check for local dampness. Excellent95/100 View detailsHide details
Generic exposed-rock guidance

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 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 surfaceProbably dryPeak gust15 mphRain0.0 mm
Mapped summit rock 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 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.

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

A broad surface report is enough; you do not need to identify a particular route.

Overnight · Aurora, stars & meteorsAfter darkBetaClearer spells are possible, but other forecasts keep much of the sky obscured by cloud. View forecastClose forecast

After dark: aurora and stargazing

Night beginning 2026-09-21. All times are UK local time.

Stargazing

Poor sky conditions during the best available spell: 22 Sep, 03:00 BST to 04:00 BST.

Clearer spells are possible, but other forecasts keep much of the sky obscured by cloud.

Moon-free dark sky: 22 Sep, 01:30 BST to 05:05 BST.

Sky conditions through the night
Fully dark periods. Conditions can change between forecast hours.
TimeViewing conditions
21 Sep, 21:10 BST to 22:00 BSTPoor sky conditions

Cloud breaks may offer some views of the stars. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.

21 Sep, 22:00 BST to 23:00 BSTPoor sky conditions

Clearer spells are possible, but other forecasts keep much of the sky obscured by cloud.

Forecast models disagree.

21 Sep, 23:00 BST to 22 Sep, 00:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects.

22 Sep, 00:00 BST to 01:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects.

22 Sep, 01:00 BST to 02:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects.

22 Sep, 02:00 BST to 03:00 BSTPoor sky conditions

Clearer spells are possible, but other forecasts keep much of the sky obscured by cloud.

Forecast models disagree.

22 Sep, 03:00 BST to 04:00 BSTPoor 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 BSTPoor 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 BSTPoor 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, 17:35 BST.

Moonset around 22 Sep, 01:30 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 926 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.

Does the weather shape your plans?Optional hill-user research. One answer helps; further questions are up to you.Take part

Help the Mountain Decisions Project understand how forecasts influence hill days, including when plans stay the same. Findings will be shared publicly as summaries, not individual responses.

This is about Fan Llia on Monday 21 September 2026. It asks about intentions, not whether you actually went out. No name or account is needed.

Open the questions to take part.

About the research and your privacy · Already been out? Share that experience instead

Confidence: Medium
Overall hill weather90/100Excellent
Wind0-15 mph westerly Gusts5-15 mph Feels like10 to 14°C PrecipitationLittle or none Cloud-free summit estimate70% Freezing levelAbove summit DaylightSunrise 06:59 · Sunset 19:13 · 12.2 hours daylight

The day on the hill

Little rain and limited summit cloud on Fan Llia: summit wind broadly 0-15 mph, with gusts 5-15 mph at times (light winds).

Cloud & views

Cloud base mostly around 900–1200 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.

Very little direct sunshine is forecast.

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 0.8 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
Less than 1 hour
Later
Less than 1 hour

Overnight forecast: 17:00–08:00 (UK local time), in Wild camping below.

Morning · 08:00–12:00 Excellent Summit winds around 0-10 mph. Gusts around 5-15 mph are possible on exposed ground.
90/100
Afternoon · 12:00–17:00 Excellent Summit winds around 0-10 mph. Gusts around 5-15 mph are possible on exposed ground.
90/100

Compare an early start with later conditions. The main forecast above covers the day in more detail.

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
Night beginning Tuesday 22 September 2026

Full overnight outlook

Open-hillside camping looks very good overall around 600 m (92/100). Light winds are expected on open ground, though local shelter and exposure still matter. Little overnight rain is forecast. Some condensation is possible overnight. The forecast does not have sufficiently broad dry and light-wind support for an exceptional grade. The grade is capped at 92/100.

Overnight rain0.0 mm Open ground · 600 m7 mph · gusts 13 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 10°C or lower

Moon overnight

Waxing gibbous moon

Illuminated disc
86%
Moonrise
17:50 BST
Moonset
02:52 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: 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)

300 m92/100 · very good
Wind / gust
6 mph / 11 mph
Typical / low
13.5°C / 12.0°C
In cloud
0% of modelled night
Condensation
Moderate
600 m92/100 · very good
Wind / gust
7 mph / 13 mph
Typical / low
13.5°C / 12.0°C
In cloud
0% of modelled night
Condensation
Moderate

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.

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

Approximate height is enough, please do not share an exact wild-camp location.

Daytime · exposed rockClimbing & scramblingBetaRock is likely to be mostly dry, but check for local dampness. Excellent95/100 View detailsHide details
Generic exposed-rock guidance

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 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 surfaceProbably dryPeak gust9 mphRain0.0 mm
Mapped summit rock 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 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.

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

A broad surface report is enough; you do not need to identify a particular route.

Overnight · Aurora, stars & meteorsAfter darkBetaClearer spells are possible, but other forecasts keep much of the sky obscured by cloud. View forecastClose forecast

After dark: aurora and stargazing

Night beginning 2026-09-22. All times are UK local time.

Stargazing

Poor sky conditions during the best available spell: 23 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: 23 Sep, 02:45 BST to 05:05 BST.

Sky conditions through the night
Fully dark periods. Conditions can change between forecast hours.
TimeViewing conditions
22 Sep, 21:05 BST to 22:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.

22 Sep, 22:00 BST to 23:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.

22 Sep, 23:00 BST to 23 Sep, 00:00 BSTPoor sky conditions

Cloud breaks may offer some views of the stars. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.

23 Sep, 00:00 BST to 01:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.

23 Sep, 01:00 BST to 02:00 BSTPoor 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 BSTPoor sky conditions

Clearer spells are possible, but other forecasts keep much of the sky obscured by cloud.

Forecast models disagree.

23 Sep, 03:00 BST to 04:00 BSTPoor sky conditions

Clearer spells are possible, but other forecasts keep much of the sky obscured by cloud.

Forecast models disagree.

23 Sep, 04:00 BST to 05:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects.

23 Sep, 05:00 BST to 05:05 BSTPoor sky conditions

Clearer spells are possible, but other forecasts keep much of the sky obscured by cloud.

Forecast models disagree.

Moon, darkness and meteor showers

Gibbous moon, about 85% illuminated.

Moonrise around 22 Sep, 17:50 BST.

Moonset around 23 Sep, 02:45 BST.

Full darkness: 22 Sep, 21:05 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 926 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.

Does the weather shape your plans?Optional hill-user research. One answer helps; further questions are up to you.Take part

Help the Mountain Decisions Project understand how forecasts influence hill days, including when plans stay the same. Findings will be shared publicly as summaries, not individual responses.

This is about Fan Llia on Tuesday 22 September 2026. It asks about intentions, not whether you actually went out. No name or account is needed.

Open the questions to take part.

About the research and your privacy · Already been out? Share that experience instead

Confidence: Medium
Overall hill weather74/100Good
Wind10-25 mph northwesterly Gusts20-30 mph Feels like4 to 8°C PrecipitationUp to around 2 mm Cloud-free summit estimate80% Cloud base through day600-1,600 m Freezing levelAbove summit DaylightSunrise 07:01 · Sunset 19:11 · 12.2 hours daylight

The day on the hill

On Fan Llia: summit wind broadly 10-25 mph, with gusts 20-30 mph at times (a moderate breeze).

Things to watch

Thunderstorms are possible from the morning into the afternoon. Keep an escape route from exposed ridges and descend if thunder develops.

If a thunderstorm develops, sudden gusts and heavy rain can change conditions quickly.

Cloud & views

Cloud base around 600–900 m in the morning, lifting to 800–1100 m around midday and 1300–1600 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.

Drizzle is forecast at times. The forecast total is up to around 2 mm, but local amounts will vary.

Forecast models differ on summit wind strength: around 14-31 mph at walker height, with gusts 19-43 mph.

Forecast confidence

Cloud height remains uncertain, especially where it is close to summit level. A low thunderstorm risk remains difficult to time precisely.

Cloud-free timing: Around 50% early, improving to around 95% later.

Sunshine context Model-grid estimate, not summit sunshine

The surrounding model grid indicates 7.2 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.

Early
0 h
Midday
3 h
Later
3 h

Overnight forecast: 17:00–08:00 (UK local time), in Wild camping below.

Morning · 08:00–12:00 Good Summit winds around 5-15 mph. Gusts around 15-25 mph are possible on exposed ground. Summit cloud becomes more persistent later.
72/100
Afternoon · 12:00–17:00 Good Summit winds around 10-20 mph. Gusts around 15-25 mph are possible on exposed ground. Rain is forecast during this period.
75/100

Compare an early start with later conditions. The main forecast above covers the day in more detail.

Overnight · 17:00–08:00Wild campingBetaA broadly very good night on a well-chosen pitch. 91/100Excellent · 600 m View detailsHide details
Night beginning Wednesday 23 September 2026

Full overnight outlook

Open-hillside camping looks very good overall around 600 m (91/100). It may be breezy on open ground, with gusts near 25 mph. Wind direction may change substantially during the night. Shelter that works at dusk may be less effective later. Little overnight rain is forecast.

Overnight rain0.0 mm Open ground · 600 m9 mph · gusts 25 mph Morning pack-upNo wet signal Sleeping-bag warmthISO comfort rating about 6°C or lower

Moon overnight

Waxing gibbous moon

Illuminated disc
92%
Moonrise
18:05 BST
Moonset
04:09 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)

300 m92/100 · very good
Wind / gust
8 mph / 21 mph
Typical / low
8.5°C / 8.0°C · much of the night
In cloud
0% of modelled night
Condensation
Low
600 m91/100 · very good
Wind / gust
9 mph / 25 mph
Typical / low
8.5°C / 8.0°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.

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

Approximate height is enough, please do not share an exact wild-camp location.

Daytime · exposed rockClimbing & scramblingBetaWet rock is likely. Low thunderstorm risk. Avoid exposed rock if storms develop. Poor36/100 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Conditions for exposed scrambling look poor (36/100). Rain during the climbing period 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. Low thunderstorm risk, broadly from the morning into the afternoon. Avoid committing to exposed ground if storms develop.

Rock surfaceWet rock likelyPeak gust26 mphRain1.2 mm
Main factorslow thunderstorm risk on exposed groundwet rock likely
Mapped summit rock 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 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.

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

A broad surface report is enough; you do not need to identify a particular route.

Overnight · Aurora, stars & meteorsAfter darkBetaMostly clear skies are forecast. Moonlight washes out fainter stars. View forecastClose forecast

After dark: aurora and stargazing

Night beginning 2026-09-23. All times are UK local time.

Stargazing

Mixed sky conditions during the best available spell: 23 Sep, 21:05 BST to 22:00 BST.

Mostly clear skies are forecast. Moonlight washes out fainter stars.

Moon-free dark sky: 24 Sep, 04:00 BST to 05:10 BST.

Sky conditions through the night
Fully dark periods. Conditions can change between forecast hours.
TimeViewing conditions
23 Sep, 21:05 BST to 22:00 BSTMixed sky conditions

Mostly clear skies are forecast. Moonlight washes out fainter stars.

23 Sep, 22:00 BST to 23:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.

23 Sep, 23:00 BST to 24 Sep, 00:00 BSTPoor sky conditions

Cloud breaks may offer some views of the stars. Moonlight washes out fainter stars.

24 Sep, 00:00 BST to 01:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.

24 Sep, 01:00 BST to 02:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.

24 Sep, 02:00 BST to 03:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.

24 Sep, 03:00 BST to 04:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects.

24 Sep, 04:00 BST to 05:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects.

24 Sep, 05:00 BST to 05:10 BSTPoor 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 92% illuminated.

Moonrise around 23 Sep, 18:05 BST.

Moonset around 24 Sep, 04:00 BST.

Full darkness: 23 Sep, 21:05 BST to 24 Sep, 05:10 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 926 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.

Does the weather shape your plans?Optional hill-user research. One answer helps; further questions are up to you.Take part

Help the Mountain Decisions Project understand how forecasts influence hill days, including when plans stay the same. Findings will be shared publicly as summaries, not individual responses.

This is about Fan Llia on Wednesday 23 September 2026. It asks about intentions, not whether you actually went out. No name or account is needed.

Open the questions to take part.

About the research and your privacy · Already been out? Share that experience instead

Confidence: High
Overall hill weather84/100Good
Wind10-25 mph southerly Gusts20-30 mph Feels like4 to 8°C PrecipitationLittle or none Cloud-free summit estimate95% Freezing levelAbove summit DaylightSunrise 07:02 · Sunset 19:08 · 12.1 hours daylight

The day on the hill

Little rain and limited summit cloud on Fan Llia: summit wind broadly 10-25 mph, with gusts 20-30 mph at times (a moderate breeze).

Cloud & views

Cloud base around 1100–1400 m in the morning, then around 1500–1800 m around midday and 1200–1500 m by late afternoon. The summit is likely to stay mostly clear.

Rain & temperature

Little or no rain is forecast.

Forecast confidence

Cloud height remains uncertain, especially where it is close to summit level.

Sunshine context Model-grid estimate, not summit sunshine

The surrounding model grid indicates 10.7 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
1.7 h
Midday
4 h
Later
3 h

Overnight forecast: 17:00–08:00 (UK local time), in Wild camping below.

Morning · 08:00–12:00 Excellent Summit winds around 5-15 mph. Gusts around 15-25 mph are possible on exposed ground.
89/100
Afternoon · 12:00–17:00 Good Winds strengthen compared with the morning. Summit winds around 10-20 mph. Gusts around 20-30 mph are possible on exposed ground.
78/100

Compare an early start with later conditions. The main forecast above covers the day in more detail.

Overnight · 17:00–08:00Wild campingBetaGusts near 30 mph make meaningful shelter important. 59/100Mixed · 600 m View detailsHide details
Night beginning Thursday 24 September 2026

Full overnight outlook

Open-hillside camping looks mixed overall around 600 m (59/100). Open-ground gusts may reach about 30 mph. Seek meaningful shelter. Peak gusts range from about 25 mph at 300 m to 30 mph at 600 m. Little overnight rain is forecast. Pitches near 600 m may spend part of the night in cloud, bringing damp conditions and poor visibility while cloud is present. Condensation risk is high near 300 and 600 m. Ventilation will matter.

Overnight rain0.0 mm Open ground · 600 m19 mph · gusts 32 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 8°C or lower

Moon overnight

Waxing gibbous moon

Illuminated disc
97%
Moonrise
18:18 BST
Moonset
05:27 next morning BST

Extensive cloud may limit moonlight. Illumination describes the sunlit part of the Moon, not brightness at your pitch.

Overnight window: 24 Sep, 17:00 BST to 25 Sep, 08:00 BST. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.

Elevation reference (open ground)

300 m64/100 · reasonable
Wind / gust
16 mph / 27 mph
Typical / low
11.2°C / 11.0°C
In cloud
0% of modelled night
Condensation
High
600 m59/100 · mixed
Wind / gust
19 mph / 32 mph
Typical / low
11.2°C / 11.0°C
In cloud
27% 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.

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

Approximate height is enough, please do not share an exact wild-camp location.

Daytime · exposed rockClimbing & scramblingBetaRock is likely to be mostly dry, but check for local dampness. Excellent92/100 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Conditions for exposed scrambling look excellent (92/100). Rock is likely to be mostly dry, though seepage and shaded holds are not resolved. 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 surfaceProbably dryPeak gust26 mphRain0.0 mm
Mapped summit rock 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 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.

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

A broad surface report is enough; you do not need to identify a particular route.

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 2026-09-24. All times are UK local time.

Aurora outlook

No significant activity expected.

A broad activity outlook, not a forecast of a visible display. Cloud and activity can change before the night.

Stargazing

Poor sky conditions during the best available spell: 24 Sep, 21:00 BST to 22:00 BST.

Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.

A bright Moon remains above the horizon through full darkness, washing out fainter stars and meteors.

Sky conditions through the night
Fully dark periods. Conditions can change between forecast hours.
TimeViewing conditions
24 Sep, 21:00 BST to 22:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.

24 Sep, 22:00 BST to 23:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.

24 Sep, 23:00 BST to 25 Sep, 00:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.

25 Sep, 00:00 BST to 01:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.

25 Sep, 01:00 BST to 02:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.

25 Sep, 02:00 BST to 03:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.

25 Sep, 03:00 BST to 04:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.

25 Sep, 04:00 BST to 05:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects.

25 Sep, 05:00 BST to 05:10 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects.

Moon, darkness and meteor showers

Near-full moon, about 96% illuminated.

Moonrise around 24 Sep, 18:20 BST.

Moonset around 25 Sep, 05:15 BST.

Full darkness: 24 Sep, 21:00 BST to 25 Sep, 05:10 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 926 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.

Does the weather shape your plans?Optional hill-user research. One answer helps; further questions are up to you.Take part

Help the Mountain Decisions Project understand how forecasts influence hill days, including when plans stay the same. Findings will be shared publicly as summaries, not individual responses.

This is about Fan Llia on Thursday 24 September 2026. It asks about intentions, not whether you actually went out. No name or account is needed.

Open the questions to take part.

About the research and your privacy · Already been out? Share that experience instead

Confidence: Medium
Overall hill weather62/100Mixed
Wind5-20 mph westerly Gusts15-25 mph Feels like6 to 10°C PrecipitationUp to around 2 mm Cloud-free summit estimate45% Cloud base through day600-900 m Freezing levelAbove summit DaylightSunrise 07:04 · Sunset 19:06 · 12.0 hours daylight

The day on the hill

Frequent summit cloud on Fan Llia: summit wind broadly 5-20 mph, with gusts 15-25 mph at times (a moderate breeze).

Cloud & views

Cloud base mostly around 600–900 m through daylight. Summit cloud is likely, but brief clear spells remain possible if the cloud sits higher than expected.

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. Any sunshine may be confined to lower ground or breaks away from the summit.

Drizzle is forecast for much of the day. The forecast total is up to around 2 mm, but local amounts will vary.

Forecast confidence

Cloud height remains uncertain, especially where it is close to summit level. Rain timing may shift by several hours, which could change how much of the main walking period stays dry.

Sunshine context Model-grid estimate, not summit sunshine

The surrounding model grid indicates 3.1 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
2 h
Later
Less than 1 hour

Overnight forecast: 17:00–08:00 (UK local time), in Wild camping below.

Morning · 08:00–12:00 Mixed Summit winds around 10-20 mph. Gusts around 15-25 mph are possible on exposed ground. Rain is possible during the main walking period, but its timing may shift by several hours.
64/100
Afternoon · 12:00–17:00 Mixed Summit winds around 5-15 mph. Gusts around 15-25 mph are possible on exposed ground. Rain is forecast during this period. Rain is possible during the main walking period, but its timing may shift by several hours.
61/100

Compare an early start with later conditions. The main forecast above covers the day in more detail.

Overnight · 17:00–08:00Wild campingBetaAbout 1.5 mm is forecast, with rain possible around pitching time. 64/100Mixed · 600 m View detailsHide details
Night beginning Friday 25 September 2026

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. Around 1.5 mm is forecast, including rain around pitching time. Condensation risk is high near 300 and 600 m, so a wet pack-up is possible. Ventilation will matter.

Overnight rain1.5 mm Open ground · 600 m7 mph · gusts 14 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 4°C or lower

Moon overnight

Near-full moon

Illuminated disc
99%
Moonrise
18:29 BST
Moonset
06:45 next morning BST

Extensive cloud may limit moonlight. Illumination describes the sunlit part of the Moon, not brightness at your pitch.

Overnight window: 25 Sep, 17:00 BST to 26 Sep, 08:00 BST. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.

Elevation reference (open ground)

300 m64/100 · reasonable
Wind / gust
6 mph / 12 mph
Typical / low
8.1°C / 7.3°C · much of the night
In cloud
0% of modelled night
Condensation
High
600 m64/100 · reasonable
Wind / gust
7 mph / 14 mph
Typical / low
8.1°C / 7.3°C · much of the night
In cloud
0% 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 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

Approximate height is enough, please do not share an exact wild-camp location.

Daytime · exposed rockClimbing & scramblingBetaWet rock is likely. Poor30/100 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Conditions for exposed scrambling look poor (30/100). Rain during the climbing period 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. Cloud may also make route-finding and retreat harder.

Rock surfaceWet rock likelyPeak gust19 mphRain1.2 mm
Main factorswet rock likelymuch of the route may be in cloud
Mapped summit rock 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 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.

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

A broad surface report is enough; you do not need to identify a particular route.

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 2026-09-25. All times are UK local time.

Aurora outlook

No significant activity expected.

A broad activity outlook, not a forecast of a visible display. Cloud and activity can change before the night.

Stargazing

Poor sky conditions during the best available spell: 26 Sep, 01:00 BST to 02:00 BST.

Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.

A bright Moon remains above the horizon through full darkness, washing out fainter stars and meteors.

Sky conditions through the night
Fully dark periods. Conditions can change between forecast hours.
TimeViewing conditions
25 Sep, 21:00 BST to 22:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Rain may interrupt viewing. Moonlight washes out fainter stars.

25 Sep, 22:00 BST to 23:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.

25 Sep, 23:00 BST to 26 Sep, 00:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.

26 Sep, 00:00 BST to 01:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.

26 Sep, 01:00 BST to 02:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.

26 Sep, 02:00 BST to 03:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.

26 Sep, 03:00 BST to 04:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.

26 Sep, 04:00 BST to 05:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.

26 Sep, 05:00 BST to 05:15 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.

Moon, darkness and meteor showers

Near-full moon, about 99% illuminated.

Moonrise around 25 Sep, 18:30 BST.

Moonset around 26 Sep, 06:35 BST.

Full darkness: 25 Sep, 21:00 BST to 26 Sep, 05:15 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 926 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.

Does the weather shape your plans?Optional hill-user research. One answer helps; further questions are up to you.Take part

Help the Mountain Decisions Project understand how forecasts influence hill days, including when plans stay the same. Findings will be shared publicly as summaries, not individual responses.

This is about Fan Llia on Friday 25 September 2026. It asks about intentions, not whether you actually went out. No name or account is needed.

Open the questions to take part.

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Confidence: Unavailable
Overall hill weather64/100Mixed
Wind5-15 mph southerly Gusts5-15 mph Feels like4 to 8°C PrecipitationLittle or none Cloud-free summit estimate45% Cloud base through day500-800 m Freezing levelAbove summit DaylightSunrise 07:06 · Sunset 19:04 · 12.0 hours daylight

The day on the hill

Frequent summit cloud on Fan Llia: summit wind broadly 5-15 mph, with gusts 5-15 mph at times (light winds).

Cloud & views

Cloud base mostly around 500–800 m through daylight. Summit cloud is likely, but brief clear spells remain possible if the cloud sits higher than expected.

Cloud-height uncertainty could put the summit in or out of cloud. Clear spells may be difficult to time.

Any sunshine may be confined to lower ground or breaks away from the summit.

Rain & temperature

Little or no rain is forecast. Forecast models disagree markedly on summit wind strength.

Check again nearer the time.

Forecast confidence

Overall confidence is unavailable: insufficient comparable wind, rain guidance.

Sunshine context Model-grid estimate, not summit sunshine

The surrounding model grid indicates 11 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
2 h
Midday
4 h
Later
3 h

Overnight forecast: 17:00–08:00 (UK local time), in Wild camping below.

Morning · 08:00–12:00 Mixed Summit winds around 0-10 mph. Gusts around 5-15 mph are possible on exposed ground.
64/100
Afternoon · 12:00–17:00 Mixed Summit winds around 5-15 mph. Gusts around 5-15 mph are possible on exposed ground.
64/100

Compare an early start with later conditions. The main forecast above covers the day in more detail.

Overnight · 17:00–08:00Wild campingBetaGusts near 35 mph make meaningful shelter important. 39/100Poor · 600 m View detailsHide details
Night beginning Saturday 26 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 600 m. Open-ground gusts may reach about 35 mph. Seek meaningful shelter. Peak gusts range from about 30 mph at 300 m to 35 mph at 600 m. Around 4.9 mm is forecast, including rain around pack-up. Pitches near 600 m may spend part of the night in cloud, bringing damp conditions and poor visibility while cloud is present. Condensation risk is high near 300 and 600 m. Ventilation will matter.

Overnight rain4.9 mm Open ground · 600 m14 mph · gusts 34 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 6°C or lower

Moon overnight

Near-full moon

Illuminated disc
100%
Moonrise
18:41 BST
Moonset
Outside this window

Cloud at the reference camping height may hide the Moon. Illumination describes the sunlit part of the Moon, not brightness at your pitch.

Overnight window: 26 Sep, 17:00 BST to 27 Sep, 08:00 BST. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.

Elevation reference (open ground)

300 m59/100 · mixed
Wind / gust
12 mph / 29 mph
Typical / low
10.1°C / 9.7°C · several hours
In cloud
0% of modelled night
Condensation
High
600 m39/100 · poor
Wind / gust
14 mph / 34 mph
Typical / low
10.1°C / 9.7°C · several hours
In cloud
60% 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 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

Approximate height is enough, please do not share an exact wild-camp location.

Daytime · exposed rockClimbing & scramblingBetaRock may be damp or still drying. Mixed50/100 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Conditions for exposed scrambling look mixed (50/100). Some rock may still be damp or drying, especially on polished slabs and vegetated 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. Cloud may also make route-finding and retreat harder.

Rock surfaceDamp or dryingPeak gust12 mphRain0.0 mm
Main factorsdamp or incompletely dried rock possiblemuch of the route may be in cloud
Mapped summit rock 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 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.

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

A broad surface report is enough; you do not need to identify a particular route.

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 2026-09-26. All times are UK local time.

Aurora outlook

No significant activity expected.

A broad activity outlook, not a forecast of a visible display. Cloud and activity can change before the night.

Stargazing

Poor sky conditions during the best available spell: 26 Sep, 20:55 BST to 21:00 BST.

Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.

A bright Moon remains above the horizon through full darkness, washing out fainter stars and meteors.

Sky conditions through the night
Fully dark periods. Conditions can change between forecast hours.
TimeViewing conditions
26 Sep, 20:55 BST to 21:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.

26 Sep, 21:00 BST to 22:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.

26 Sep, 22:00 BST to 23:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.

26 Sep, 23:00 BST to 27 Sep, 00:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.

27 Sep, 00:00 BST to 01:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.

27 Sep, 01:00 BST to 02:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Rain may interrupt viewing. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.

Limited model coverage.

27 Sep, 02:00 BST to 03:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Rain may interrupt viewing. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.

Limited model coverage.

27 Sep, 03:00 BST to 04:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Rain may interrupt viewing. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.

Limited model coverage.

27 Sep, 04:00 BST to 05:00 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Rain may interrupt viewing. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.

Limited model coverage.

27 Sep, 05:00 BST to 05:15 BSTPoor sky conditions

Cloud is likely to obscure much of the sky. Rain may interrupt viewing. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.

Limited model coverage.

Moon, darkness and meteor showers

Near-full moon, about 100% illuminated.

Moonrise around 26 Sep, 18:40 BST.

Moonset around 27 Sep, 07:55 BST.

Full darkness: 26 Sep, 20:55 BST to 27 Sep, 05:15 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 926 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.

Does the weather shape your plans?Optional hill-user research. One answer helps; further questions are up to you.Take part

Help the Mountain Decisions Project understand how forecasts influence hill days, including when plans stay the same. Findings will be shared publicly as summaries, not individual responses.

This is about Fan Llia on Saturday 26 September 2026. It asks about intentions, not whether you actually went out. No name or account is needed.

Open the questions to take part.

About the research and your privacy · Already been out? Share that experience instead

Confidence: Unavailable
Overall hill weather62/100Mixed
Wind15-30 mph southwesterly Gusts30-40 mph Feels like4 to 8°C PrecipitationAround 2-5 mm Cloud-free summit estimate75% Cloud base through day700-1,300 m Freezing levelAbove summit DaylightSunrise 07:07 · Sunset 19:01 · 11.9 hours daylight

The day on the hill

A wet day on Fan Llia: summit wind broadly 15-30 mph, with gusts 30-40 mph at times (a fresh breeze). Visibility may drop briefly in showers.

Wind & exposure

Much calmer lower down - generally 5-15 mph in the valley, rising towards the tops.

Cloud & views

Cloud base around 700–1000 m through the morning, lifting to 1000–1300 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.

Cloud may hang lower on southwestern slopes and lift somewhat on the northeastern side, but local terrain can differ. Drizzle is forecast for much of the day, with some passing showers too.

The forecast total is around 2-5 mm, but local amounts will vary. Forecast models differ on summit wind strength.

Treat the wind figures as a guide.

Forecast confidence

Cloud height remains uncertain, especially where it is close to summit level. Overall confidence is unavailable: insufficient comparable wind, rain guidance.

Cloud-free timing: Around 70% early, improving to around 90% later.

Sunshine context Model-grid estimate, not summit sunshine

The surrounding model grid indicates 7.5 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
Less than 1 hour
Midday
3.2 h
Later
2.9 h

Overnight forecast: 17:00–08:00 (UK local time), in Wild camping below.

Morning · 08:00–12:00 Mixed Summit winds around 20-30 mph. Gusts around 30-40 mph are possible on exposed ground. Rain is forecast during this period.
56/100
Afternoon · 12:00–17:00 Mixed Summit winds around 15-25 mph. Gusts around 25-35 mph are possible on exposed ground. Rain is forecast during this period.
69/100

Compare an early start with later conditions. The main forecast above covers the day in more detail.

Overnight · 17:00–08:00Wild campingBetaCondensation risk is high near 300 and 600 m. 64/100Mixed · 600 m View detailsHide details
Night beginning Sunday 27 September 2026

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. A little rain may coincide with pitching or packing up. Condensation risk is high near 300 and 600 m, so a wet pack-up is possible. Ventilation will matter.

Overnight rain0.5 mm Open ground · 600 m16 mph · gusts 24 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 8°C or lower

Moon overnight

Waning gibbous moon

Illuminated disc
98%
Moonrise
18:53 BST
Moonset
Outside this window

Extensive cloud may limit moonlight. Illumination describes the sunlit part of the Moon, not brightness at your pitch.

Overnight window: 27 Sep, 17:00 BST to 28 Sep, 08:00 BST. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.

Elevation reference (open ground)

300 m64/100 · reasonable
Wind / gust
13 mph / 20 mph
Typical / low
10.9°C / 10.3°C
In cloud
0% of modelled night
Condensation
High
600 m64/100 · reasonable
Wind / gust
16 mph / 24 mph
Typical / low
10.9°C / 10.3°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.

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

Approximate height is enough, please do not share an exact wild-camp location.

Daytime · exposed rockClimbing & scramblingBetaWet rock is likely. Gusts near 35 mph may affect balance on exposed rock. Poor45/100 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Conditions for exposed scrambling look mixed (45/100). Rain during the climbing period 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 35 mph. Crosswinds can make exposed ridges substantially more serious.

Rock surfaceWet rock likelyPeak gust33 mphRain3.7 mm
Main factorsgusts around 35 mphwet rock likely
Mapped summit rock 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 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.

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

A broad surface report is enough; you do not need to identify a particular route.

Overnight · Aurora, stars & meteorsAfter darkBetaNight-sky guidance is unavailable for this night. View forecastClose forecast

After dark: aurora and stargazing

Night-sky guidance is unavailable for this night. This does not mean clear skies or no aurora.

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.

Does the weather shape your plans?Optional hill-user research. One answer helps; further questions are up to you.Take part

Help the Mountain Decisions Project understand how forecasts influence hill days, including when plans stay the same. Findings will be shared publicly as summaries, not individual responses.

This is about Fan Llia on Sunday 27 September 2026. It asks about intentions, not whether you actually went out. No name or account is needed.

Open the questions to take part.

About the research and your privacy · Already been out? Share that experience instead

Weather data: Open-Meteo (CC BY 4.0). Adapted by Mountain Weather.

Forecast run: 2026-09-20

Keep exploring

Weather around Fan Llia.

Compare the summit forecast with the wider regional picture and nearby peaks before choosing a route.

Regional mountain forecastBannau Brycheiniog (Brecon Beacons)View area →
Fan Nedd663 m · 2.5 km awayForecast →Fan Fawr734 m · 3.2 km awayForecast →Craig Cerrig-gleisiad629 m · 3.9 km awayForecast →Fan Frynych628 m · 4.6 km awayForecast →

A forecast is part of the decision.

Mountain weather can differ sharply from conditions in the valley. Check official warnings, carry appropriate navigation and clothing, and be ready to change the plan. Read how Mountain Weather forecasts are produced and where their limits lie.

Choose another summit