690 m summit in Bannau Brycheiniog (Brecon Beacons). 8 forecast days covering wind, cloud, rain and temperature, updated 4 November 2026 at 06:35 UTC.
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Confidence: Medium
Overall hill weather70Good
Summit wind · 08:00-17:0015-30 mph easterlySummit gusts · 08:00-17:0030-40 mphFeels like-4 to 0°CPrecipitationUp to around 2 mmCloud-free summit estimate85%Cloud base through day900-1,200 mFreezing levelAbove summitDaylightSunrise 07:12 · Sunset 16:39 · 9.4 hours daylight
The day on the hill
A good day on Twmpa: breezy, with clear tops for most of the day.
Wind
On the summit expect an easterly wind of 15–30 mph for most of the day, with gusts of 30–40 mph at the windiest. Lower down on the open hillside it will be more like 5–15 mph. Gusts like that will be noticeable on ridges and open tops, and you will chill quickly when you stop.
Cloud and visibility
The tops are likely to drift in and out of cloud, with the best chance of a clear summit mid-morning. The cloud base sits close to summit height, so the top could go in and out of cloud at short notice.
Rain and ground
A band of rain crosses around midday, clearing by early afternoon.
Warmth and kit
On the tops it will be around 2 to 6°C, feeling like -4 to 0°C in the wind. The freezing level is above the summits. Take a hat, gloves, a windproof and a spare warm layer.
Daylight
Sunset is around 4:40pm, so allow time to get off the hill before dark, and carry a head torch.
Forecast confidence
Cloud height is hard to pin down, so the summit could be in or out of cloud at short notice. Things could still change through the day, so keep an eye on the sky.
Sunshine context Model-grid estimate, not summit sunshine
The surrounding model grid indicates 1.6 h of sunshine. This is not a forecast of time in sunshine on the summit. Use the cloud and views outlook above for the conditions on this mountain.
Morning · 08:00–12:00
GoodSummit winds around 15-30 mph. Gusts around 30-40 mph are possible on exposed ground. Summit cloud is more persistent early in this period, with better prospects later.
71
Afternoon · 12:00–17:00
MixedSummit winds around 15-30 mph. Gusts around 30-40 mph are possible on exposed ground. Rain is forecast during this period.
69
Compare an early start with later conditions. The main forecast above covers the day in more detail.
Overnight · 17:00–08:00Wild campingBetaA poor night to camp on open ground: gusts of about 40 mph.39Poor · 600 mView detailsHide details
Night beginning Wednesday 4 November 2026
Full overnight outlook
A poor night to camp on open ground. Gusts reach about 40 mph on open ground, which makes for a noisy, testing night even in a good tent. Look for shelter from the east. It should stay dry. The air is damp at every height we checked (300-600 m), so expect heavy condensation. Leave the vents open. A cold night, down to about 3°C around 300 m. A warm 3-season or 3–4 season bag rated to about 0°C comfort, and a warm mat, should do. Allow more if you sleep cold.
Extensive cloud may limit moonlight. Illumination describes the sunlit part of the Moon, not brightness at your pitch.
Overnight window: 4 Nov, 17:00 GMT to 5 Nov, 08:00 GMT. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.
Elevation reference (open ground)
300 m59 · mixed
Wind / gust
20 mph / 32 mph
Typical / low
3.4°C / 2.7°C · much of the night
In cloud
0% of modelled night
Condensation
High
600 m39 · poor
Wind / gust
24 mph / 38 mph
Typical / low
3.4°C / 2.7°C · much of the night
In cloud
0% of modelled night
Condensation
High
Warmth planning: As a broad starting point, consider a warm 3-season or 3–4 season bag with an ISO/EN comfort rating at or below about 0°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.
Did this match your night?Share a quick observation to help improve this beta forecast.Give feedback →
Daytime · exposed rockClimbing & scramblingBetaFair conditions for exposed scrambling: gusts of 30–40 mph.Mixed61View detailsHide details
Generic exposed-rock guidance
Full climbing & scrambling outlook
Fair conditions for exposed scrambling. The rock should be drying, but damp patches, shaded holds and drainage lines may still be wet. Gusts of 30–40 mph could throw you off balance on exposed moves and ridges. The rock around the summit is mostly sandstone, a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away. These are general notes for each rock type, taken from geological maps around the summit, so the rock on your line may differ.
Rock surfaceDamp or dryingPeak gust30-40 mphRain0.2 mm
Main factorsgusts of 30–40 mphdamp or incompletely dried rock possible
Most common mapped rock around the summit
Sandstone with clay-rich rockSenni Formation
Origin
Sedimentary
Broad rock-response group
Sandstone or gritstone
Mapping
BGS Geology 50K · 1:50,000
Summit area
Sandstone or gritstone in 59% of 17 BGS samples within 350 m
Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away. These are general notes for each rock type, from geological map samples at and around the summit. The rock on your line can differ, and lichen, vegetation and seepage all change how it feels underfoot.
Geological detail and BGS records
Mapped variation
2 rock types appear in the mapped samples
Samples around the summit inform the main rock-response profile, with the summit pin shown separately where it differs. Route samples add further context, but this is not a continuous geological survey.
Summit-area sample
Sandstone with clay-rich rockSenni Formation
Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away.
BGS record →
Summit-area sample
Clay-rich rock with sandstoneFreshwater West Formation
Mudstone or slate is a soft, fine-grained rock that splits into thin flakes. It has only fair grip even when dry and is slippery when wet. It is often shattered, breaking into loose flakes, scree and poor holds.
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 Twmpa on Wednesday 4 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Summit wind · 08:00-17:0010-30 mph easterlySummit gusts · 08:00-17:0035-45 mphFeels like-6 to -2°CPrecipitationLittle or noneCloud-free summit estimate55%Cloud base through day700-1,000 mFreezing levelAbove summitDaylightSunrise 07:13 · Sunset 16:37 · 9.4 hours daylight
The day on the hill
A mixed day on Twmpa, with a blustery wind.
Wind
On the summit expect an easterly wind of around 20–30 mph first thing, easing to 10–20 mph by mid-afternoon, with gusts of 35–45 mph at the windiest. Lower down on the open hillside it will be more like 5–15 mph. Gusts like that are strong enough to make walking into it hard work, with buffeting on ridges and edges.
Cloud and visibility
Cloud on the tops early should lift off them by midday. The cloud base sits close to summit height, so the top could go in and out of cloud at short notice.
Rain and ground
It should stay dry.
Warmth and kit
On the tops it will be around 0 to 4°C, feeling like -6 to -2°C in the wind. The freezing level is above the summits. Take a hat, gloves, a windproof and a spare warm layer.
Daylight
Sunset is around 4:35pm, so allow time to get off the hill before dark, and carry a head torch.
Forecast confidence
Cloud height is hard to pin down, so the summit could be in or out of cloud at short notice. Some of the detail could still change, so have a last look at the forecast in the morning before you set off.
Sunshine context Model-grid estimate, not summit sunshine
The surrounding model grid indicates 0 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.
Morning · 08:00–12:00
MixedSummit winds around 20-30 mph early in the morning, easing to 10-20 mph later. Gusts around 35-45 mph are possible on exposed ground. Gusts this strong can make walking into it hard work, with buffeting on ridges and edges.
50
Afternoon · 12:00–17:00
ExcellentSummit winds around 10-20 mph. Gusts around 20-30 mph are possible on exposed ground. Summit cloud is more persistent early in this period, with better prospects later.
86
Compare an early start with later conditions. The main forecast above covers the day in more detail.
Overnight · 17:00–08:00Wild campingBetaA mixed night to camp, mainly because of the rain: gusts of about 20 mph.59Mixed · 600 mView detailsHide details
Night beginning Thursday 5 November 2026
Full overnight outlook
A mixed night to camp, mainly because of the rain. Light winds on open ground, gusting no more than about 20 mph. Dry to pitch, then some light rain by morning, so you'll likely pack up in the wet. The air is damp at every height we checked (300-600 m), so expect heavy condensation. Leave the vents open. A cold night, down to about 3°C around 300 m. A warm 3-season or 3–4 season bag rated to about 0°C comfort, and a warm mat, should do. Allow more if you sleep cold.
Extensive cloud may limit moonlight. Illumination describes the sunlit part of the Moon, not brightness at your pitch.
Overnight window: 5 Nov, 17:00 GMT to 6 Nov, 08:00 GMT. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.
Elevation reference (open ground)
300 m59 · mixed
Wind / gust
10 mph / 19 mph
Typical / low
3.4°C / 2.9°C · much of the night
In cloud
0% of modelled night
Condensation
High
600 m59 · mixed
Wind / gust
11 mph / 22 mph
Typical / low
3.4°C / 2.9°C · much of the night
In cloud
0% of modelled night
Condensation
High
Warmth planning: As a broad starting point, consider a warm 3-season or 3–4 season bag with an ISO/EN comfort rating at or below about 0°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.
Did this match your night?Share a quick observation to help improve this beta forecast.Give feedback →
Daytime · exposed rockClimbing & scramblingBetaMixed conditions for exposed scrambling: gusts of 35–45 mph.Mixed59View detailsHide details
Generic exposed-rock guidance
Full climbing & scrambling outlook
Mixed conditions for exposed scrambling. The rock should be mostly dry, though drainage lines and shaded holds may still be damp. Gusts of 35–45 mph could throw you off balance on exposed moves and ridges. Cloud on the tops may make route-finding and retreat harder. The rock around the summit is mostly sandstone, a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away. These are general notes for each rock type, taken from geological maps around the summit, so the rock on your line may differ.
Rock surfaceProbably dryPeak gust35-45 mphRain0.0 mm
Main concerngusts of 35–45 mph
Most common mapped rock around the summit
Sandstone with clay-rich rockSenni Formation
Origin
Sedimentary
Broad rock-response group
Sandstone or gritstone
Mapping
BGS Geology 50K · 1:50,000
Summit area
Sandstone or gritstone in 59% of 17 BGS samples within 350 m
Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away. These are general notes for each rock type, from geological map samples at and around the summit. The rock on your line can differ, and lichen, vegetation and seepage all change how it feels underfoot.
Geological detail and BGS records
Mapped variation
2 rock types appear in the mapped samples
Samples around the summit inform the main rock-response profile, with the summit pin shown separately where it differs. Route samples add further context, but this is not a continuous geological survey.
Summit-area sample
Sandstone with clay-rich rockSenni Formation
Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away.
BGS record →
Summit-area sample
Clay-rich rock with sandstoneFreshwater West Formation
Mudstone or slate is a soft, fine-grained rock that splits into thin flakes. It has only fair grip even when dry and is slippery when wet. It is often shattered, breaking into loose flakes, scree and poor holds.
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 Twmpa on Thursday 5 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Summit wind · 08:00-17:005-15 mph easterlySummit gusts · 08:00-17:0010-20 mphFeels like-2 to 2°CPrecipitationUp to around 2 mmCloud-free summit estimate20%Cloud base through day600-900 mFreezing levelAbove summitDaylightSunrise 07:15 · Sunset 16:35 · 9.3 hours daylight
The day on the hill
A mixed day on Twmpa, with the summit in cloud for most of the day.
Wind
On the summit expect light winds of up to 15 mph, mainly easterly, with gusts of 10–20 mph at the windiest.
Cloud and visibility
Expect the summit to be in cloud for most of the day. The cloud base sits close to summit height, so the top could go in and out of cloud at short notice. In cloud you'll be finding your way without landmarks, so carry navigation you trust and know how to use, with a backup such as a spare battery or a map and compass.
Rain and ground
Drizzle at first, clearing by mid-afternoon. The timing could shift by a few hours.
Warmth and kit
On the tops it will be around 0 to 4°C, feeling like -2 to 2°C in the wind. The freezing level is above the summits. Take a hat, gloves, a windproof and a spare warm layer. Pack waterproofs too, and keep a warm layer dry in your pack.
Daylight
Sunset is around 4:35pm, so allow time to get off the hill before dark, and carry a head torch.
Forecast confidence
It's still two days off and could change, so check again nearer the time.
Sunshine context Model-grid estimate, not summit sunshine
The surrounding model grid indicates 0 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.
Morning · 08:00–12:00
MixedSummit winds around 5-15 mph. Gusts around 10-20 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.
64
Afternoon · 12:00–17:00
MixedSummit winds around 5-15 mph. Gusts around 10-20 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.
63
Compare an early start with later conditions. The main forecast above covers the day in more detail.
Overnight · 17:00–08:00Wild campingBetaA mixed night to camp, mainly because of damp air: gusts of about 10 mph.59Mixed · 600 mView detailsHide details
Night beginning Friday 6 November 2026
Full overnight outlook
A mixed night to camp, mainly because of damp air. Light winds on open ground, gusting no more than about 10 mph. Dry to pitch, then a little rain overnight, easing by morning, though the tent may still be wet. The air is damp at every height we checked (300-600 m), so expect heavy condensation. Leave the vents open. Overnight lows of about 4°C at 300 m. A warm 3-season or 3–4 season bag rated to about 0°C comfort, and a warm mat, should do. Allow more if you sleep cold.
Cloud may affect views of the Moon. Illumination describes the sunlit part of the Moon, not brightness at your pitch.
Overnight window: 6 Nov, 17:00 GMT to 7 Nov, 08:00 GMT. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.
Elevation reference (open ground)
300 m59 · mixed
Wind / gust
6 mph / 10 mph
Typical / low
4.3°C / 3.9°C · much of the night
In cloud
0% of modelled night
Condensation
High
600 m59 · mixed
Wind / gust
7 mph / 12 mph
Typical / low
4.3°C / 3.9°C · much of the night
In cloud
20% of modelled night
Condensation
High
Warmth planning: As a broad starting point, consider a warm 3-season or 3–4 season bag with an ISO/EN comfort rating at or below about 0°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.
Poor conditions for exposed scrambling. The rock is likely to be wet and slippery through the day. Cloud on the tops may make route-finding and retreat harder. The rock around the summit is mostly sandstone, a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away. These are general notes for each rock type, taken from geological maps around the summit, so the rock on your line may differ.
Rock surfaceWet rock likelyPeak gust10-20 mphRain1.1 mm
Main factorswet rock likelymuch of the route may be in cloud
Most common mapped rock around the summit
Sandstone with clay-rich rockSenni Formation
Origin
Sedimentary
Broad rock-response group
Sandstone or gritstone
Mapping
BGS Geology 50K · 1:50,000
Summit area
Sandstone or gritstone in 59% of 17 BGS samples within 350 m
Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away. These are general notes for each rock type, from geological map samples at and around the summit. The rock on your line can differ, and lichen, vegetation and seepage all change how it feels underfoot.
Geological detail and BGS records
Mapped variation
2 rock types appear in the mapped samples
Samples around the summit inform the main rock-response profile, with the summit pin shown separately where it differs. Route samples add further context, but this is not a continuous geological survey.
Summit-area sample
Sandstone with clay-rich rockSenni Formation
Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away.
BGS record →
Summit-area sample
Clay-rich rock with sandstoneFreshwater West Formation
Mudstone or slate is a soft, fine-grained rock that splits into thin flakes. It has only fair grip even when dry and is slippery when wet. It is often shattered, breaking into loose flakes, scree and poor holds.
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 Twmpa on Friday 6 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Summit wind · 08:00-17:000-10 mph southeasterlySummit gusts · 08:00-17:005-15 mphFeels like-2 to 2°CPrecipitationLittle or noneCloud-free summit estimate40%Cloud base through day500-800 mFreezing levelAbove summitDaylightSunrise 07:17 · Sunset 16:34 · 9.3 hours daylight
The day on the hill
A good day on Twmpa, though expect cloud coming and going on the summit.
Wind
On the summit expect light winds of up to 10 mph, mainly south-easterly, with gusts of 5–15 mph at the windiest.
Cloud and visibility
The tops are likely to drift in and out of cloud, with the best chance of a clear summit mid-afternoon. The cloud base could be as low as 500–800 m in the early afternoon. In cloud you'll be finding your way without landmarks, so carry navigation you trust and know how to use, with a backup such as a spare battery or a map and compass. Mist or fog is possible in the valleys early on, clearing by about 9am.
Rain and ground
It should stay dry.
Warmth and kit
On the tops it will be around 2 to 6°C, feeling like -2 to 2°C in the wind. The freezing level is above the summits. Take a warm layer and a hat for the top.
Daylight
Sunset is around 4:35pm, so allow time to get off the hill before dark, and carry a head torch.
Forecast confidence
It's still three days off and could change, so check again nearer the time.
Sunshine context Model-grid estimate, not summit sunshine
The surrounding model grid indicates 2.5 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.
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.
Morning · 08:00–12:00
MixedSummit winds around 0-10 mph. Gusts around 5-15 mph are possible on exposed ground. Rain is possible during the main walking period, but its timing may shift by several hours.
66
Afternoon · 12:00–17:00
GoodSummit winds around 0-10 mph. Gusts around 0-10 mph are possible on exposed ground. Summit cloud is more persistent early in this period, with better prospects later. Rain is possible during the main walking period, but its timing may shift by several hours.
74
Compare an early start with later conditions. The main forecast above covers the day in more detail.
Overnight · 17:00–08:00Wild campingBetaA mixed night to camp, mainly because of the cold: dry, with light winds.59Mixed · 600 mView detailsHide details
Night beginning Saturday 7 November 2026
Full overnight outlook
A mixed night to camp, mainly because of the cold. Light winds on open ground, gusting no more than about 5 mph. It should stay dry. Overnight lows of about 4°C at 600 m. A 3-season bag rated to about 2°C comfort, and a warm mat, should do. Allow more if you sleep cold.
Cloud may affect views of the Moon. Illumination describes the sunlit part of the Moon, not brightness at your pitch.
Overnight window: 7 Nov, 17:00 GMT to 8 Nov, 08:00 GMT. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.
Elevation reference (open ground)
300 m59 · mixed
Wind / gust
2 mph / 4 mph
Typical / low
4.9°C / 4.7°C · much of the night
In cloud
0% of modelled night
Condensation
Moderate
600 m59 · mixed
Wind / gust
2 mph / 5 mph
Typical / low
4.6°C / 4.3°C · much of the night
In cloud
0% of modelled 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 2°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.
Fair conditions for exposed scrambling. It should stay mostly dry, but a passing shower could leave the rock damp and slippery. Cloud on the tops may make route-finding and retreat harder. The rock around the summit is mostly sandstone, a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away. These are general notes for each rock type, taken from geological maps around the summit, so the rock on your line may differ.
Rock surfaceDry initially; rain possiblePeak gust5-15 mphRainPossible · 35%
Main factorsrain possible despite mostly dry conditions being favouredmuch of the route may be in cloud
Most common mapped rock around the summit
Sandstone with clay-rich rockSenni Formation
Origin
Sedimentary
Broad rock-response group
Sandstone or gritstone
Mapping
BGS Geology 50K · 1:50,000
Summit area
Sandstone or gritstone in 59% of 17 BGS samples within 350 m
Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away. These are general notes for each rock type, from geological map samples at and around the summit. The rock on your line can differ, and lichen, vegetation and seepage all change how it feels underfoot.
Geological detail and BGS records
Mapped variation
2 rock types appear in the mapped samples
Samples around the summit inform the main rock-response profile, with the summit pin shown separately where it differs. Route samples add further context, but this is not a continuous geological survey.
Summit-area sample
Sandstone with clay-rich rockSenni Formation
Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away.
BGS record →
Summit-area sample
Clay-rich rock with sandstoneFreshwater West Formation
Mudstone or slate is a soft, fine-grained rock that splits into thin flakes. It has only fair grip even when dry and is slippery when wet. It is often shattered, breaking into loose flakes, scree and poor holds.
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 Twmpa on Saturday 7 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Summit wind · 08:00-17:000-15 mph westerlySummit gusts · 08:00-17:0010-20 mphFeels like-2 to 2°CPrecipitationUp to around 2 mmCloud-free summit estimate65%Cloud base through day500-1,100 mFreezing level600-900 mDaylightSunrise 07:19 · Sunset 16:32 · 9.2 hours daylight
The day on the hill
A good day on Twmpa: light winds.
Wind
On the summit expect light winds of up to 15 mph, mainly westerly, with gusts of 10–20 mph at the windiest. Lower down on the open hillside the wind will be light, under 5 mph.
Cloud and visibility
The tops start clear, but the cloud comes down onto them around midday. The cloud base could be as low as 500–800 m mid-afternoon. Mist or fog is possible in the valleys early on, clearing by about 10am. Good spells of sunshine are likely.
Rain and ground
Drizzle sets in mid-morning.
Warmth and kit
On the tops it will be around 2 to 6°C, feeling like -2 to 2°C in the wind. The freezing level is close to summit height. Take a hat, gloves, a windproof and a spare warm layer.
Daylight
Sunset is around 4:30pm, so allow time to get off the hill before dark, and carry a head torch.
Forecast confidence
Cloud height is hard to pin down, so the summit could be in or out of cloud at short notice. It's still four days off and could change, so check again nearer the time.
Sunshine context Model-grid estimate, not summit sunshine
The surrounding model grid indicates 6.5 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.
Morning · 08:00–12:00
ExcellentSummit winds around 0-15 mph. Gusts around 10-20 mph are possible on exposed ground. Rain is forecast during this period.
89
Afternoon · 12:00–17:00
MixedSummit winds around 5-15 mph. Gusts around 10-20 mph are possible on exposed ground. Rain is forecast during this period.
66
Compare an early start with later conditions. The main forecast above covers the day in more detail.
Overnight · 17:00–08:00Wild campingBetaA mixed night to camp, mainly because of damp air: gusts of about 15 mph.54Mixed · 600 mView detailsHide details
Night beginning Sunday 8 November 2026
Full overnight outlook
A mixed night to camp, mainly because of damp air. Light winds on open ground, gusting no more than about 15 mph. Dry to pitch, then a little rain overnight, easing by morning, though the tent may still be wet. Up around 600 m you'd likely be in cloud for part of the night: damp, and hard to find your way if you need to move. The air is damp at every height we checked (300-600 m), so expect heavy condensation. Leave the vents open. A cold night, down to about 2°C around 300 m. A warm 3-season or 3–4 season bag rated to about 0°C comfort, and a warm mat, should do. Allow more if you sleep cold.
Warmth planning: As a broad starting point, consider a warm 3-season or 3–4 season bag with an ISO/EN comfort rating at or below about 0°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.
Mixed conditions for exposed scrambling. The rock is likely to be wet and slippery through the day. Cloud on the tops may make route-finding and retreat harder. The rock around the summit is mostly sandstone, a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away. These are general notes for each rock type, taken from geological maps around the summit, so the rock on your line may differ.
Rock surfaceWet rock likelyPeak gust10-20 mphRain0.6 mm
Main factorswet rock likelymuch of the route may be in cloud
Most common mapped rock around the summit
Sandstone with clay-rich rockSenni Formation
Origin
Sedimentary
Broad rock-response group
Sandstone or gritstone
Mapping
BGS Geology 50K · 1:50,000
Summit area
Sandstone or gritstone in 59% of 17 BGS samples within 350 m
Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away. These are general notes for each rock type, from geological map samples at and around the summit. The rock on your line can differ, and lichen, vegetation and seepage all change how it feels underfoot.
Geological detail and BGS records
Mapped variation
2 rock types appear in the mapped samples
Samples around the summit inform the main rock-response profile, with the summit pin shown separately where it differs. Route samples add further context, but this is not a continuous geological survey.
Summit-area sample
Sandstone with clay-rich rockSenni Formation
Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away.
BGS record →
Summit-area sample
Clay-rich rock with sandstoneFreshwater West Formation
Mudstone or slate is a soft, fine-grained rock that splits into thin flakes. It has only fair grip even when dry and is slippery when wet. It is often shattered, breaking into loose flakes, scree and poor holds.
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 Twmpa on Sunday 8 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Summit wind · 08:00-17:0010-20 mph easterlySummit gusts · 08:00-17:0015-25 mphFeels like-6 to -2°CPrecipitationUp to around 2 mmCloud-free summit estimate35%Cloud base through day500-800 mFreezing level700-1,000 mDaylightSunrise 07:21 · Sunset 16:30 · 9.2 hours daylight
The day on the hill
A mixed day on Twmpa, with cloud coming and going on the summit.
Wind
On the summit expect an easterly wind of 10–20 mph for most of the day, with gusts of 15–25 mph at the windiest. Lower down on the open hillside the wind will be light, under 10 mph.
Cloud and visibility
Expect the summit to be in cloud for most of the day. The cloud base could be as low as 500–800 m mid-afternoon. In cloud you'll be finding your way without landmarks, so carry navigation you trust and know how to use, with a backup such as a spare battery or a map and compass. Mist or fog is possible in the valleys through the morning.
Rain and ground
Drizzle sets in mid-morning.
Warmth and kit
On the tops it will be around 0 to 4°C, feeling like -6 to -2°C in the wind. The freezing level is close to summit height. Take a hat, gloves, a windproof and a spare warm layer.
Daylight
Sunset is around 4:30pm, so allow time to get off the hill before dark, and carry a head torch.
Forecast confidence
Cloud height is hard to pin down, so the summit could be in or out of cloud at short notice. It's still five days off and could change, so check again nearer the time.
Sunshine context Model-grid estimate, not summit sunshine
The surrounding model grid indicates 3.8 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.
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.
Morning · 08:00–12:00
MixedSummit winds around 10-20 mph. Gusts around 15-25 mph are possible on exposed ground. Rain is forecast during this period.
55
Afternoon · 12:00–17:00
MixedSummit winds around 10-20 mph. Gusts around 15-25 mph are possible on exposed ground. Rain is forecast during this period.
62
Compare an early start with later conditions. The main forecast above covers the day in more detail.
Overnight · 17:00–08:00Wild campingBetaA mixed night to camp, mainly because of the wind: about 5 mm of rain.40Poor · 600 mView detailsHide details
Night beginning Monday 9 November 2026
Full overnight outlook
A mixed night to camp, mainly because of the wind. Gusts reach about 30 mph on open ground, so peg out well and use the guylines. Look for shelter from the east. Expect about 5 mm of rain, with rain while you pitch and still falling when you pack up. Up around 600 m you'd likely be in cloud for part of the night: damp, and hard to find your way if you need to move. A cold night, down to about 2°C around 600 m. A warm 3-season or 3–4 season bag rated to about 0°C comfort, and a warm mat, should do. Allow more if you sleep cold.
Warmth planning: As a broad starting point, consider a warm 3-season or 3–4 season bag with an ISO/EN comfort rating at or below about 0°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.
Poor conditions for exposed scrambling. The rock is likely to be wet and slippery through the day. Cloud on the tops may make route-finding and retreat harder. The rock around the summit is mostly sandstone, a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away. These are general notes for each rock type, taken from geological maps around the summit, so the rock on your line may differ.
Rock surfaceWet rock likelyPeak gust15-25 mphRain1.0 mm
Main factorswet rock likelymuch of the route may be in cloud
Most common mapped rock around the summit
Sandstone with clay-rich rockSenni Formation
Origin
Sedimentary
Broad rock-response group
Sandstone or gritstone
Mapping
BGS Geology 50K · 1:50,000
Summit area
Sandstone or gritstone in 59% of 17 BGS samples within 350 m
Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away. These are general notes for each rock type, from geological map samples at and around the summit. The rock on your line can differ, and lichen, vegetation and seepage all change how it feels underfoot.
Geological detail and BGS records
Mapped variation
2 rock types appear in the mapped samples
Samples around the summit inform the main rock-response profile, with the summit pin shown separately where it differs. Route samples add further context, but this is not a continuous geological survey.
Summit-area sample
Sandstone with clay-rich rockSenni Formation
Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away.
BGS record →
Summit-area sample
Clay-rich rock with sandstoneFreshwater West Formation
Mudstone or slate is a soft, fine-grained rock that splits into thin flakes. It has only fair grip even when dry and is slippery when wet. It is often shattered, breaking into loose flakes, scree and poor holds.
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 Twmpa on Monday 9 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
A poor day on the tops of Twmpa, with rain for much of the day and cloud on the tops early.
Wind
On the summit expect an easterly wind of 15–30 mph for most of the day, with gusts of 30–40 mph at the windiest. The wind turns south-easterly in the early afternoon. Lower down on the open hillside it will be more like 5–15 mph. Gusts like that will be noticeable on ridges and open tops, and you will chill quickly when you stop.
Cloud and visibility
Cloud on the tops early should lift off them by midday. The cloud base could be as low as 400–700 m around midday. Mist or fog is possible in the valleys early on, clearing by about 2am.
Rain and ground
Rain for much of the day. Expect 10–20 mm in total. Some forecast models keep it drier in the morning.
Warmth and kit
On the tops it will be around 2 to 6°C, feeling like -4 to 0°C in the wind. The freezing level is above the summits. Take a hat, gloves, a windproof and a spare warm layer. Pack waterproofs too, and keep a warm layer dry in your pack.
Daylight
Sunset is around 4:30pm, so allow time to get off the hill before dark, and carry a head torch.
Forecast confidence
It's still six days off and could change, so check again nearer the time.
Sunshine context Model-grid estimate, not summit sunshine
The surrounding model grid indicates 0 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.
Morning · 08:00–12:00
PoorSummit winds around 15-30 mph. Gusts around 30-40 mph are possible on exposed ground. Rain is forecast during this period. Some forecast models bring rain during the morning, while others keep it mostly dry.
31
Afternoon · 12:00–17:00
PoorSummit winds around 15-25 mph. Gusts around 25-35 mph are possible on exposed ground. Rain is forecast during this period.
43
Compare an early start with later conditions. The main forecast above covers the day in more detail.
Overnight · 17:00–08:00Wild campingBetaA mixed night to camp, mainly because of the rain: about 5 mm of rain.59Mixed · 600 mView detailsHide details
Night beginning Tuesday 10 November 2026
Full overnight outlook
A mixed night to camp, mainly because of the rain. Gusts reach about 30 mph on open ground, so peg out well and use the guylines. Look for shelter from the southeast. Expect about 5 mm of rain, with rain while you pitch and still falling when you pack up. Overnight lows of about 5°C at 300 m. A 3-season bag rated to about 2°C comfort, and a warm mat, should do. Allow more if you sleep cold.
Warmth planning: As a broad starting point, consider a 3-season bag with an ISO/EN comfort rating at or below about 2°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.
Did this match your night?Share a quick observation to help improve this beta forecast.Give feedback →
Daytime · exposed rockClimbing & scramblingBetaPoor conditions for exposed scrambling: gusts of 30–40 mph.Poor28View detailsHide details
Generic exposed-rock guidance
Full climbing & scrambling outlook
Poor conditions for exposed scrambling. The rock is likely to be wet and slippery through the day. Gusts of 30–40 mph could throw you off balance on exposed moves and ridges. Cloud on the tops may make route-finding and retreat harder. The rock around the summit is mostly sandstone, a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away. These are general notes for each rock type, taken from geological maps around the summit, so the rock on your line may differ.
Rock surfaceWet rock likelyPeak gust30-40 mphRain12.9 mm
Main factorsgusts of 30–40 mphwet rock likelymuch of the route may be in cloud
Most common mapped rock around the summit
Sandstone with clay-rich rockSenni Formation
Origin
Sedimentary
Broad rock-response group
Sandstone or gritstone
Mapping
BGS Geology 50K · 1:50,000
Summit area
Sandstone or gritstone in 59% of 17 BGS samples within 350 m
Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away. These are general notes for each rock type, from geological map samples at and around the summit. The rock on your line can differ, and lichen, vegetation and seepage all change how it feels underfoot.
Geological detail and BGS records
Mapped variation
2 rock types appear in the mapped samples
Samples around the summit inform the main rock-response profile, with the summit pin shown separately where it differs. Route samples add further context, but this is not a continuous geological survey.
Summit-area sample
Sandstone with clay-rich rockSenni Formation
Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away.
BGS record →
Summit-area sample
Clay-rich rock with sandstoneFreshwater West Formation
Mudstone or slate is a soft, fine-grained rock that splits into thin flakes. It has only fair grip even when dry and is slippery when wet. It is often shattered, breaking into loose flakes, scree and poor holds.
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 Twmpa on Tuesday 10 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Summit wind · 08:00-17:005-15 mph southwesterlySummit gusts · 08:00-17:0010-20 mphFeels like4 to 8°CPrecipitationUp to around 2 mmCloud-free summit estimate30%Cloud base through day600-900 mFreezing levelAbove summitDaylightSunrise 07:24 · Sunset 16:27 · 9.1 hours daylight
The day on the hill
A mixed day on Twmpa, with cloud coming and going on the summit.
Wind
On the summit expect light winds of up to 15 mph, mainly south-westerly, with gusts of 10–20 mph at the windiest. Lower down on the open hillside the wind will be light, under 5 mph.
Cloud and visibility
Expect the summit to be in cloud for most of the day. The cloud base sits close to summit height, so the top could go in and out of cloud at short notice. In cloud you'll be finding your way without landmarks, so carry navigation you trust and know how to use, with a backup such as a spare battery or a map and compass.
Rain and ground
Drizzle sets in during the early afternoon. It will be wet underfoot after recent rain.
Warmth and kit
On the tops it will be around 6 to 10°C, feeling like 4 to 8°C in the wind. The freezing level is above the summits.
Daylight
Sunset is around 4:25pm, so allow time to get off the hill before dark, and carry a head torch.
Forecast confidence
It's still seven days off and could change, so check again nearer the time.
Sunshine context Model-grid estimate, not summit sunshine
The surrounding model grid indicates 0 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.
Morning · 08:00–12:00
MixedSummit winds around 5-15 mph. Gusts around 5-15 mph are possible on exposed ground.
62
Afternoon · 12:00–17:00
MixedSummit winds around 5-15 mph. Gusts around 10-20 mph are possible on exposed ground. Summit cloud is more persistent early in this period, with better prospects later. Rain is forecast during this period.
57
Compare an early start with later conditions. The main forecast above covers the day in more detail.
Overnight · 17:00–08:00Wild campingBetaA mixed night to camp, mainly because of the rain: about 6 mm of rain.59Mixed · 600 mView detailsHide details
Night beginning Wednesday 11 November 2026
Full overnight outlook
A mixed night to camp, mainly because of the rain. Gusts reach about 25 mph on open ground, so peg out well and use the guylines. Look for shelter from the southwest. Expect about 6 mm of rain, with rain while you pitch and still falling when you pack up. A cold night, down to about 2°C around 300 m. A warm 3-season or 3–4 season bag rated to about 0°C comfort, and a warm mat, should do. Allow more if you sleep cold.
Warmth planning: As a broad starting point, consider a warm 3-season or 3–4 season bag with an ISO/EN comfort rating at or below about 0°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.
Poor conditions for exposed scrambling. The rock is likely to be wet and slippery through the day. Cloud on the tops may make route-finding and retreat harder. The rock around the summit is mostly sandstone, a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away. These are general notes for each rock type, taken from geological maps around the summit, so the rock on your line may differ.
Rock surfaceWet rock likelyPeak gust10-20 mphRain0.7 mm
Main factorswet rock likelymuch of the route may be in cloud
Most common mapped rock around the summit
Sandstone with clay-rich rockSenni Formation
Origin
Sedimentary
Broad rock-response group
Sandstone or gritstone
Mapping
BGS Geology 50K · 1:50,000
Summit area
Sandstone or gritstone in 59% of 17 BGS samples within 350 m
Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away. These are general notes for each rock type, from geological map samples at and around the summit. The rock on your line can differ, and lichen, vegetation and seepage all change how it feels underfoot.
Geological detail and BGS records
Mapped variation
2 rock types appear in the mapped samples
Samples around the summit inform the main rock-response profile, with the summit pin shown separately where it differs. Route samples add further context, but this is not a continuous geological survey.
Summit-area sample
Sandstone with clay-rich rockSenni Formation
Sandstone is a gritty sedimentary rock. It is rough and grippy when dry and can feel greasy when damp or covered in lichen. It is usually solid in terraced steps, but softer layers crumble and weathered edges can break away.
BGS record →
Summit-area sample
Clay-rich rock with sandstoneFreshwater West Formation
Mudstone or slate is a soft, fine-grained rock that splits into thin flakes. It has only fair grip even when dry and is slippery when wet. It is often shattered, breaking into loose flakes, scree and poor holds.
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 Twmpa on Wednesday 11 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
