Mountain Weather

Mullach nan Coirean weather forecast.

939 m summit in Lochaber. 7 forecast days covering wind, cloud, rain and temperature, updated 22 September 2026 at 16:08 UTC.

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Confidence: Medium
Overall hill weather63/100Mixed
Wind10-25 mph northwesterly Gusts20-30 mph Feels like-4 to 0°C PrecipitationLittle or none Cloud-free summit estimate45% Cloud base through day600-1,300 m Freezing levelAbove summit DaylightSunrise 07:06 · Sunset 19:17 · 12.2 hours daylight

The day on the hill

Frequent summit cloud on Mullach nan Coirean: summit wind broadly 10-25 mph, with gusts 20-30 mph at times (a fresh breeze).

Things to watch

High spate risk during the morning, after earlier rain. Timings are approximate, not a guarantee of safe crossings afterwards. Burns and unbridged crossings may become difficult or impassable. Turn back if a crossing looks unsafe.

Cloud & views

Cloud base around 600–900 m in the morning, lifting to 800–1100 m around midday and 1000–1300 m by late afternoon. The top is likely to drift in and out of cloud, with the best chance of a view during the afternoon.

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

Cloud may hang lower on northwestern slopes and lift somewhat on the southeastern side, but local terrain can differ. Sunny spells are possible away from summit cloud, but may not reach the top while it is in cloud.

Rain & temperature

The ground is likely to be saturated after recent rain. Expect boggy paths and rapid runoff if more rain arrives.

Little or no rain is forecast. Cold on exposed tops: air temperature broadly 2 to 6°C, feeling around -4 to 0°C in the wind.

Forecast confidence

Cloud height remains uncertain, especially where it is close to summit level. Keep windproof and warm layers readily available.

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 15% early, improving to around 50% later.

Sunshine context Model-grid estimate, not summit sunshine

The surrounding model grid indicates 2.7 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.

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
Less than 1 hour
Later
1.2 h

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

Morning · 08:00–12:00 Mixed Summit winds around 15-25 mph. Gusts around 20-30 mph are possible on exposed ground.
50/100
Afternoon · 12:00–17:00 Good Summit 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.
76/100

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. 72/100Good · 600 m View detailsHide details
Night beginning Wednesday 23 September 2026

Full overnight outlook

Open-hillside camping looks reasonable overall around 600 m (72/100). A lower pitch near 300 m looks more comfortable. Conditions are less suitable by 900 m. 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 900 m. Wind direction may change substantially during the night. Shelter that works at dusk may be less effective later. Little overnight rain is forecast. Pitches near 900 m may spend part of the night in cloud, bringing damp conditions and poor visibility while cloud is present. Condensation risk is high near 900 m. Ventilation will matter. The coldest temperature falls from about 5.8°C at 300 m to 4.2°C at 900 m.

Overnight rain0.0 mm Open ground · 600 m11 mph · gusts 26 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 2°C or lower

Moon overnight

Waxing gibbous moon

Illuminated disc
92%
Moonrise
18:26 BST
Moonset
04:02 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 m80/100 · promising
Wind / gust
9 mph / 23 mph
Typical / low
6.2°C / 5.8°C · much of the night
In cloud
0% of modelled night
Condensation
Moderate
600 m72/100 · reasonable
Wind / gust
11 mph / 26 mph
Typical / low
6.2°C / 5.8°C · much of the night
In cloud
0% of modelled night
Condensation
Moderate
900 m54/100 · mixed
Wind / gust
13 mph / 30 mph
Typical / low
4.4°C / 4.2°C · much of the night
In cloud
53% 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 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.

The ground is likely to be very wet after recent rain. Expect boggy approaches and choose a durable pitch carefully.

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. Poor30/100 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Conditions for exposed scrambling look poor (30/100). Recent rain may leave seepage and damp rock, especially on shaded sections. The mapped summit rock is Leucogranite (Mullach Nan Coirean Pluton). Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery. Representative samples along available mapped routes also include Pelite and calcsilicate-rock, Metaquartz-arenite and 1 other mapped type, so rock character and wet-weather behaviour may change across the mountain. Cloud may also make route-finding and retreat harder.

Rock surfaceDry overhead; seepage uncertainPeak gust27 mphRainPossible · 85%
Main factorsdamp or incompletely dried rock possiblemuch of the route may be in cloud
Mapped rock across the summit and available routes Leucogranite Mullach Nan Coirean Pluton
Origin
Igneous
Rock family
Granite, gneiss or gabbro
Mapping
BGS Geology 50K · 1:50,000
Rock-response profile
Moderate confidence
View the summit BGS record

Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery. Summit-point mapping plus representative BGS bedrock samples along available GPX routes. These are not continuous geological surveys; contacts, superficial deposits and the exposed rock on individual holds may differ.

Rock groups along the sampled routes

These are mapped rock groups, not separate weather forecasts or a ranking of route safety.

Stob Bàn (Mamores) and Mullach nan Coirean

psammite, pelite or semipelite, sandstone or gritstone, granite, gneiss or gabbro

Geological detail and BGS records
Mapped variation

4 rock types appear across the available route samples

The summit type remains the forecast's cautious rock-response reference. Other mapped types show where conditions may behave differently elsewhere on the mountain.

Summit mapping Leucogranite Mullach Nan Coirean Pluton Around 637 m Seen on Stob Bàn (Mamores) and Mullach nan Coirean

Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery.

BGS record
Route sample Pelite and calcsilicate-rock Leven Schist Formation 171–521 m samples Seen on Stob Bàn (Mamores) and Mullach nan Coirean

Dry quartz-rich bands can be grippy, while mica-rich or foliated sections, lichen and vegetation may become slippery when wet.

BGS record
Route sample Metaquartz-arenite Glen Coe Quartzite Member 874–989 m samples Seen on Stob Bàn (Mamores) and Mullach nan Coirean

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.

BGS record
Route sample Porphyritic microdiorite Ben Nevis Dyke Swarm Around 52 m Seen on Stob Bàn (Mamores) and Mullach nan Coirean

Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery.

BGS record

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 Mullach nan Coirean 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: Medium
Overall hill weather45/100Poor
Wind30-45 mph southerly Gusts50-60 mph Feels like-4 to 0°C PrecipitationAround 2-5 mm Cloud-free summit estimate80% Cloud base through day900-1,900 m Freezing levelAbove summit DaylightSunrise 07:08 · Sunset 19:15 · 12.1 hours daylight

The day on the hill

Strong gusts on Mullach nan Coirean: summit wind broadly 30-45 mph, with gusts 50-60 mph at times (gale-force mean winds at times).

Wind & exposure

Much calmer lower down - generally 15-25 mph in the valley, rising towards the tops.

Cloud & views

Cloud base around 1600–1900 m in the morning, lowering to 1500–1800 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.

Cloud may hang lower on southern slopes and lift somewhat on the northern side, but local terrain can differ. Drizzle is forecast at times.

The forecast total is around 2-5 mm, but local amounts will vary. Cold on exposed tops: air temperature broadly 2 to 6°C, feeling around -4 to 0°C in the wind.

Forecast models differ on summit wind strength: around 33-52 mph at walker height, with gusts 46-72 mph.

Rain & temperature

The ground is likely to be wet after recent rain.

Forecast confidence

Cloud height remains uncertain, especially where it is close to summit level. Keep windproof and warm layers readily available.

If clothing gets wet, you can cool more quickly. Keep a dry warm layer protected.

Walking into the wind is likely to be arduous, with buffeting that can knock you off balance. Forecast models differ on whether meaningful rain reaches the hills during the afternoon and evening.

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

Sunshine context Model-grid estimate, not summit sunshine

The surrounding model grid indicates 5.1 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.

Early
2 h
Midday
0.9 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 15-25 mph. Gusts around 30-40 mph are possible on exposed ground. Buffeting may affect balance on exposed ground, particularly near ridges and edges.
61/100
Afternoon · 12:00–17:00 Poor Winds strengthen compared with the morning. Summit winds around 35-45 mph. Gusts around 50-60 mph are possible on exposed ground. Gusts may knock you off balance on exposed ground, even between spells of lighter wind. Rain is forecast during this period. Rain is possible during the afternoon, but forecast models disagree on whether it will fall.
29/100

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

Overnight · 17:00–08:00Wild campingBetaExposed camping is not recommended near 300, 600 and 900 m: gusts may reach about 60 mph. Sustained winds may reach about 40 mph at times. Choose an alternative off the exposed hill. Do not rely on finding shelter after setting out. 9/100Poor · 600 m View detailsHide details
Night beginning Thursday 24 September 2026

Full overnight outlook

Exposed camping is not recommended near 300, 600 and 900 m: gusts may reach about 60 mph. Sustained winds may reach about 40 mph at times. Choose an alternative off the exposed hill. Do not rely on finding shelter after setting out. Open-hillside camping looks very poor overall around 600 m (9/100). Peak gusts range from about 40 mph at 300 m to 60 mph at 900 m. Roughly 9.7 mm is forecast overnight, including rain around pitching time. Pitches near 600 and 900 m may spend part of the night in cloud, bringing damp conditions and poor visibility while cloud is present. Condensation risk is high near 600 and 900 m. Ventilation will matter. The coldest temperature falls from about 8°C at 300 m to 5.3°C at 900 m.

Overnight rain9.7 mm Open ground · 600 m29 mph · gusts 50 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 4°C or lower

Moon overnight

Waxing gibbous moon

Illuminated disc
97%
Moonrise
18:32 BST
Moonset
05:27 next morning BST

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: 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 m19/100 · very poor
Wind / gust
24 mph / 42 mph
Typical / low
8.5°C / 8.0°C · much of the night
In cloud
0% of modelled night
Condensation
Moderate
600 m9/100 · very poor
Wind / gust
29 mph / 50 mph
Typical / low
8.0°C / 7.5°C · much of the night
In cloud
40% of modelled night
Condensation
High
900 m9/100 · very poor
Wind / gust
34 mph / 59 mph
Typical / low
5.9°C / 5.3°C · much of the night
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 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. Gusts near 55 mph may affect balance on exposed rock. Poor0/100 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Conditions for exposed scrambling look very poor (0/100). Rain during the climbing period is likely to leave rock wet and more slippery. The mapped summit rock is Leucogranite (Mullach Nan Coirean Pluton). Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery. Representative samples along available mapped routes also include Pelite and calcsilicate-rock, Metaquartz-arenite and 1 other mapped type, so rock character and wet-weather behaviour may change across the mountain. Gusts may reach about 55 mph. Crosswinds can make exposed ridges substantially more serious.

Rock surfaceWet rock likelyPeak gust57 mphRain1.5 mm
Main factorsgusts around 55 mphwet rock likely
Mapped rock across the summit and available routes Leucogranite Mullach Nan Coirean Pluton
Origin
Igneous
Rock family
Granite, gneiss or gabbro
Mapping
BGS Geology 50K · 1:50,000
Rock-response profile
Moderate confidence
View the summit BGS record

Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery. Summit-point mapping plus representative BGS bedrock samples along available GPX routes. These are not continuous geological surveys; contacts, superficial deposits and the exposed rock on individual holds may differ.

Rock groups along the sampled routes

These are mapped rock groups, not separate weather forecasts or a ranking of route safety.

Stob Bàn (Mamores) and Mullach nan Coirean

psammite, pelite or semipelite, sandstone or gritstone, granite, gneiss or gabbro

Geological detail and BGS records
Mapped variation

4 rock types appear across the available route samples

The summit type remains the forecast's cautious rock-response reference. Other mapped types show where conditions may behave differently elsewhere on the mountain.

Summit mapping Leucogranite Mullach Nan Coirean Pluton Around 637 m Seen on Stob Bàn (Mamores) and Mullach nan Coirean

Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery.

BGS record
Route sample Pelite and calcsilicate-rock Leven Schist Formation 171–521 m samples Seen on Stob Bàn (Mamores) and Mullach nan Coirean

Dry quartz-rich bands can be grippy, while mica-rich or foliated sections, lichen and vegetation may become slippery when wet.

BGS record
Route sample Metaquartz-arenite Glen Coe Quartzite Member 874–989 m samples Seen on Stob Bàn (Mamores) and Mullach nan Coirean

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.

BGS record
Route sample Porphyritic microdiorite Ben Nevis Dyke Swarm Around 52 m Seen on Stob Bàn (Mamores) and Mullach nan Coirean

Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery.

BGS record

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 Mullach nan Coirean 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 weather28/100Poor
Wind20-35 mph southwesterly Gusts35-45 mph Feels like-2 to 2°C PrecipitationAround 2-5 mm Cloud-free summit estimate25% Cloud base through day500-1,000 m Freezing levelAbove summit DaylightSunrise 07:10 · Sunset 19:12 · 12.0 hours daylight

The day on the hill

A wet day with extensive summit cloud on Mullach nan Coirean: summit wind broadly 20-35 mph, with gusts 35-45 mph at times (strong winds). Visibility may drop briefly in showers.

Patchy mist is possible in sheltered valleys early on.

Wind & exposure

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

Cloud & views

Cloud base around 500–800 m in the morning, lifting to 700–1000 m around midday. Cloud is likely to cover the top for much of the day, though a brief clearance is possible during the afternoon.

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

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.

Cold on exposed tops: air temperature broadly 4 to 8°C, feeling around -2 to 2°C in the wind. Forecast models differ on summit wind strength: around 19-39 mph at walker height, with gusts 27-55 mph.

Rain & temperature

The ground is likely to be saturated after recent rain. Expect boggy paths and rapid runoff if more rain arrives.

Forecast confidence

Cloud height remains uncertain, especially where it is close to summit level. Keep windproof and warm layers readily available.

If clothing gets wet, you can cool more quickly. Keep a dry warm layer protected.

Buffeting may affect balance on exposed ground, particularly near ridges and edges. Summit wind could be roughly 19-39 mph, which changes how difficult exposed walking may feel.

Cloud-free timing: Around 10% early, improving to around 30% later.

Sunshine context Model-grid estimate, not summit sunshine

The surrounding model grid indicates 9 h of sunshine. This is not a forecast of time in sunshine on the summit. Use the cloud and views outlook above for the conditions on this mountain.

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
1.2 h
Midday
4 h
Later
1.8 h

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

Morning · 08:00–12:00 Poor Summit winds around 20-30 mph. Gusts around 35-45 mph are possible on exposed ground. Buffeting may affect balance on exposed ground, particularly near ridges and edges. Rain is forecast during this period.
25/100
Afternoon · 12:00–17:00 Poor Summit winds around 20-30 mph. Gusts around 35-45 mph are possible on exposed ground. Buffeting may affect balance on exposed ground, particularly near ridges and edges. Summit cloud is more persistent early in this period, with better prospects later. Rain is forecast during this period.
30/100

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

Overnight · 17:00–08:00Wild campingBetaExposed camping is not recommended near 900 m: gusts may reach about 45 mph. Sustained winds may reach about 30 mph at times. Lower sheltered ground may be less exposed, but this forecast does not confirm a suitable pitch or a safe approach. Check its overnight conditions separately. 39/100Poor · 600 m View detailsHide details
Night beginning Friday 25 September 2026

Full overnight outlook

Exposed camping is not recommended near 900 m: gusts may reach about 45 mph. Sustained winds may reach about 30 mph at times. Lower sheltered ground may be less exposed, but this forecast does not confirm a suitable pitch or a safe approach. Check its overnight conditions separately. Open-hillside camping looks poor overall around 600 m (39/100). Peak gusts range from about 30 mph at 300 m to 45 mph at 900 m. Roughly 5.3 mm is forecast overnight, with rain liable to affect both pitching and packing up. Pitches near 600 and 900 m may spend part of the night in cloud, bringing damp conditions and poor visibility while cloud is present. Condensation risk is high near 600 and 900 m. Ventilation will matter. The coldest temperature falls from about 6.9°C at 300 m to 4.6°C at 900 m.

Overnight rain5.3 mm Open ground · 600 m24 mph · gusts 37 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 4°C or lower

Moon overnight

Near-full moon

Illuminated disc
99%
Moonrise
18:37 BST
Moonset
06:53 next morning BST

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: 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 m59/100 · mixed
Wind / gust
20 mph / 31 mph
Typical / low
7.7°C / 6.9°C · much of the night
In cloud
0% of modelled night
Condensation
Moderate
600 m39/100 · poor
Wind / gust
24 mph / 37 mph
Typical / low
7.2°C / 6.4°C · much of the night
In cloud
87% of modelled night
Condensation
High
900 m19/100 · very poor
Wind / gust
29 mph / 44 mph
Typical / low
5.3°C / 4.6°C · several hours
In cloud
100% 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.

The ground is likely to be very wet after recent rain. Expect boggy approaches and choose a durable pitch carefully.

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 40 mph may affect balance on exposed rock. Poor0/100 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Conditions for exposed scrambling look very poor (0/100). Rain during the climbing period is likely to leave rock wet and more slippery. The mapped summit rock is Leucogranite (Mullach Nan Coirean Pluton). Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery. Representative samples along available mapped routes also include Pelite and calcsilicate-rock, Metaquartz-arenite and 1 other mapped type, so rock character and wet-weather behaviour may change across the mountain. Gusts may reach about 40 mph. Crosswinds can make exposed ridges substantially more serious. Cloud may also make route-finding and retreat harder.

Rock surfaceWet rock likelyPeak gust39 mphRain4.2 mm
Main factorsgusts around 40 mphwet rock likelymuch of the route may be in cloud
Mapped rock across the summit and available routes Leucogranite Mullach Nan Coirean Pluton
Origin
Igneous
Rock family
Granite, gneiss or gabbro
Mapping
BGS Geology 50K · 1:50,000
Rock-response profile
Moderate confidence
View the summit BGS record

Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery. Summit-point mapping plus representative BGS bedrock samples along available GPX routes. These are not continuous geological surveys; contacts, superficial deposits and the exposed rock on individual holds may differ.

Rock groups along the sampled routes

These are mapped rock groups, not separate weather forecasts or a ranking of route safety.

Stob Bàn (Mamores) and Mullach nan Coirean

psammite, pelite or semipelite, sandstone or gritstone, granite, gneiss or gabbro

Geological detail and BGS records
Mapped variation

4 rock types appear across the available route samples

The summit type remains the forecast's cautious rock-response reference. Other mapped types show where conditions may behave differently elsewhere on the mountain.

Summit mapping Leucogranite Mullach Nan Coirean Pluton Around 637 m Seen on Stob Bàn (Mamores) and Mullach nan Coirean

Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery.

BGS record
Route sample Pelite and calcsilicate-rock Leven Schist Formation 171–521 m samples Seen on Stob Bàn (Mamores) and Mullach nan Coirean

Dry quartz-rich bands can be grippy, while mica-rich or foliated sections, lichen and vegetation may become slippery when wet.

BGS record
Route sample Metaquartz-arenite Glen Coe Quartzite Member 874–989 m samples Seen on Stob Bàn (Mamores) and Mullach nan Coirean

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.

BGS record
Route sample Porphyritic microdiorite Ben Nevis Dyke Swarm Around 52 m Seen on Stob Bàn (Mamores) and Mullach nan Coirean

Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery.

BGS record

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 Mullach nan Coirean 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: Low
Overall hill weather2/100Poor
Wind30-50 mph southwesterly Gusts55-65 mph Feels like-2 to 2°C PrecipitationAround 5-10 mm Cloud-free summit estimate15% Cloud base through day500-1,000 m Freezing levelAbove summit DaylightSunrise 07:12 · Sunset 19:09 · 11.9 hours daylight

The day on the hill

Strong gusts and frequent summit cloud on Mullach nan Coirean: summit wind broadly 30-50 mph, with gusts 55-65 mph at times (gale-force mean winds at times). Visibility may drop briefly in showers.

Things to watch

High spate risk through the day and overnight, with forecast rain and subsequent runoff. Risk may continue beyond the daytime period shown. Timings are approximate, not a guarantee of safe crossings afterwards. Burns and unbridged crossings may become difficult or impassable. Turn back if a crossing looks unsafe.

Wind & exposure

Much calmer lower down - generally 10-20 mph in the valley, rising towards the tops. Summit wind strength is uncertain: around 25-55 mph at walker height, with gusts 35-76 mph.

Check again nearer the time.

Cloud & views

Cloud base around 500–800 m in the morning, lifting to 700–1000 m around midday. 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 southwestern slopes and lift somewhat on the northeastern 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, with some passing showers too. The forecast total is around 5-10 mm, but local amounts will vary.

Cold on exposed tops: air temperature broadly 4 to 8°C, feeling around -2 to 2°C in the wind.

Rain & temperature

The ground is likely to be wet after recent rain.

Forecast confidence

Cloud height remains uncertain, especially where it is close to summit level. Keep windproof and warm layers readily available.

If clothing gets wet, you can cool more quickly. Keep a dry warm layer protected.

Walking into the wind is likely to be arduous, with buffeting that can knock you off balance. Summit wind could be roughly 25-55 mph, which changes how difficult exposed walking may feel.

Cloud-free timing: Best around midday at about 20%. Lowest early at about 10%.

Sunshine context Model-grid estimate, not summit sunshine

The surrounding model grid indicates 4.2 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.

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
1.2 h
Midday
2 h
Later
0 h

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

Morning · 08:00–12:00 Poor Summit winds around 25-35 mph. Gusts around 40-50 mph are possible on exposed ground. Gusts may knock you off balance on exposed ground, even between spells of lighter wind. Rain is forecast during this period.
13/100
Afternoon · 12:00–17:00 Severe hill conditions Winds strengthen compared with the morning. Summit winds around 30-40 mph in the early afternoon, strengthening to 35-45 mph later. Gusts around 55-65 mph are possible on exposed ground. Walking into the wind is likely to be arduous, with buffeting that can knock you off balance. Rain is forecast during this period.
0/100

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

Overnight · 17:00–08:00Wild campingBetaExposed camping is not recommended near 300, 600 and 900 m: gusts may reach about 60 mph. Sustained winds may reach about 45 mph at times. Choose an alternative off the exposed hill. Do not rely on finding shelter after setting out. 9/100Poor · 600 m View detailsHide details
Night beginning Saturday 26 September 2026

Full overnight outlook

Exposed camping is not recommended near 300, 600 and 900 m: gusts may reach about 60 mph. Sustained winds may reach about 45 mph at times. Choose an alternative off the exposed hill. Do not rely on finding shelter after setting out. Open-hillside camping looks very poor overall around 600 m (9/100). Peak gusts range from about 45 mph at 300 m to 60 mph at 900 m. Roughly 34.5 mm is forecast overnight, with rain liable to affect both pitching and packing up. Pitches near 600 and 900 m may spend part of the night in cloud, bringing damp conditions and poor visibility while cloud is present. Condensation risk is high near 600 and 900 m. Ventilation will matter. The coldest temperature falls from about 9.1°C at 300 m to 5.9°C at 900 m.

Overnight rain34.5 mm Open ground · 600 m32 mph · gusts 53 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 6°C or lower

Moon overnight

Near-full moon

Illuminated disc
100%
Moonrise
18:42 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 m19/100 · very poor
Wind / gust
27 mph / 44 mph
Typical / low
10.4°C / 9.1°C · several hours
In cloud
0% of modelled night
Condensation
Moderate
600 m9/100 · very poor
Wind / gust
32 mph / 53 mph
Typical / low
9.6°C / 8.2°C · much of the night
In cloud
73% of modelled night
Condensation
High
900 m9/100 · very poor
Wind / gust
38 mph / 62 mph
Typical / low
7.8°C / 5.9°C · much of the night
In cloud
87% 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 & scramblingBetaWet rock is likely. Gusts near 60 mph may affect balance on exposed rock. Poor0/100 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Conditions for exposed scrambling look very poor (0/100). Rain during the climbing period is likely to leave rock wet and more slippery. The mapped summit rock is Leucogranite (Mullach Nan Coirean Pluton). Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery. Representative samples along available mapped routes also include Pelite and calcsilicate-rock, Metaquartz-arenite and 1 other mapped type, so rock character and wet-weather behaviour may change across the mountain. Gusts may reach about 60 mph. Crosswinds can make exposed ridges substantially more serious. Cloud may also make route-finding and retreat harder.

Rock surfaceWet rock likelyPeak gust60 mphRain5.9 mm
Main factorsgusts around 60 mphwet rock likelymuch of the route may be in cloud
Mapped rock across the summit and available routes Leucogranite Mullach Nan Coirean Pluton
Origin
Igneous
Rock family
Granite, gneiss or gabbro
Mapping
BGS Geology 50K · 1:50,000
Rock-response profile
Moderate confidence
View the summit BGS record

Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery. Summit-point mapping plus representative BGS bedrock samples along available GPX routes. These are not continuous geological surveys; contacts, superficial deposits and the exposed rock on individual holds may differ.

Rock groups along the sampled routes

These are mapped rock groups, not separate weather forecasts or a ranking of route safety.

Stob Bàn (Mamores) and Mullach nan Coirean

psammite, pelite or semipelite, sandstone or gritstone, granite, gneiss or gabbro

Geological detail and BGS records
Mapped variation

4 rock types appear across the available route samples

The summit type remains the forecast's cautious rock-response reference. Other mapped types show where conditions may behave differently elsewhere on the mountain.

Summit mapping Leucogranite Mullach Nan Coirean Pluton Around 637 m Seen on Stob Bàn (Mamores) and Mullach nan Coirean

Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery.

BGS record
Route sample Pelite and calcsilicate-rock Leven Schist Formation 171–521 m samples Seen on Stob Bàn (Mamores) and Mullach nan Coirean

Dry quartz-rich bands can be grippy, while mica-rich or foliated sections, lichen and vegetation may become slippery when wet.

BGS record
Route sample Metaquartz-arenite Glen Coe Quartzite Member 874–989 m samples Seen on Stob Bàn (Mamores) and Mullach nan Coirean

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.

BGS record
Route sample Porphyritic microdiorite Ben Nevis Dyke Swarm Around 52 m Seen on Stob Bàn (Mamores) and Mullach nan Coirean

Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery.

BGS record

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 Mullach nan Coirean 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: Medium
Overall hill weather19/100Poor
Wind20-30 mph southwesterly Gusts35-45 mph Feels like-4 to 0°C PrecipitationAround 5-10 mm Cloud-free summit estimate80% Cloud base through day1,300-1,900 m Freezing levelAbove summit DaylightSunrise 07:14 · Sunset 19:06 · 11.9 hours daylight

The day on the hill

A wet day on Mullach nan Coirean: summit wind broadly 20-30 mph, with gusts 35-45 mph at times (strong winds). Visibility may drop briefly in showers.

Things to watch

Severe spate risk through much of the day and into the night, with recent and forecast rain and subsequent runoff. Risk may continue beyond the daytime period shown. Timings are approximate, not a guarantee of safe crossings afterwards. Burns and unbridged crossings may become difficult or impassable. Turn back if a crossing looks unsafe.

Wind & exposure

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

Cloud & views

Cloud base around 1300–1600 m in the morning, lifting to 1500–1800 m around midday and 1600–1900 m by late afternoon. Cloud is likely to come and go across the top, with views in the clearer spells.

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. Sunny spells are possible away from summit cloud, but may not reach the top while it is in cloud.

Drizzle is forecast for much of the day, with some passing showers too. The forecast total is around 5-10 mm, but local amounts will vary.

Cold on exposed tops: air temperature broadly 2 to 6°C, feeling around -4 to 0°C in the wind. Forecast models differ on summit wind strength: around 21-32 mph at walker height, with gusts 29-45 mph.

Rain & temperature

The ground is likely to be wet after recent rain.

Forecast confidence

Cloud height remains uncertain, especially where it is close to summit level. Keep windproof and warm layers readily available.

If clothing gets wet, you can cool more quickly. Keep a dry warm layer protected.

Buffeting may affect balance on exposed ground, particularly near ridges and edges. Forecast models differ on whether meaningful rain reaches the hills during the morning.

Cloud-free timing: Around 70% early, falling to around 60% later.

Sunshine context Model-grid estimate, not summit sunshine

The surrounding model grid indicates 10.9 h of sunshine. This is not a forecast of time in sunshine on the summit. Use the cloud and views outlook above for the conditions on this mountain.

Early
2 h
Midday
4 h
Later
2.9 h

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

Morning · 08:00–12:00 Poor Summit winds around 20-30 mph. Gusts around 35-45 mph are possible on exposed ground. Buffeting may affect balance on exposed ground, particularly near ridges and edges. Summit cloud is more persistent early in this period, with better prospects later. Rain is forecast during this period. Rain is possible during the morning, but forecast models disagree on whether it will fall. Rain is possible during the main walking period, but its timing may shift by several hours.
25/100
Afternoon · 12:00–17:00 Poor Summit winds around 20-30 mph. Gusts around 35-45 mph are possible on exposed ground. Buffeting may affect balance on exposed ground, particularly near ridges and edges. Rain is forecast during this period. Rain is possible during the main walking period, but its timing may shift by several hours.
13/100

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. 59/100Mixed · 600 m View detailsHide details
Night beginning Sunday 27 September 2026

Full overnight outlook

Open-hillside camping looks mixed overall around 600 m (59/100). A lower pitch near 300 m looks more comfortable. Conditions are less suitable by 900 m. Open-ground gusts may reach about 35 mph. Seek meaningful shelter. Peak gusts range from about 25 mph at 300 m to 35 mph at 900 m. Little overnight rain is forecast. Pitches near 900 m may spend part of the night in cloud, bringing damp conditions and poor visibility while cloud is present. The coldest temperature falls from about 7.2°C at 300 m to 4.3°C at 900 m.

Overnight rain0.0 mm Open ground · 600 m15 mph · gusts 28 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 4°C or lower

Moon overnight

Waning gibbous moon

Illuminated disc
98%
Moonrise
18:48 BST
Moonset
Outside this window

Clear spells may allow a view of the Moon. 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 m82/100 · promising
Wind / gust
13 mph / 23 mph
Typical / low
7.5°C / 7.2°C · much of the night
In cloud
0% of modelled night
Condensation
Low
600 m59/100 · mixed
Wind / gust
15 mph / 28 mph
Typical / low
6.7°C / 6.3°C · much of the night
In cloud
0% of modelled night
Condensation
Low
900 m59/100 · mixed
Wind / gust
18 mph / 33 mph
Typical / low
4.4°C / 4.3°C · much of the night
In cloud
33% 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 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. Gusts near 40 mph may affect balance on exposed rock. Poor6/100 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Conditions for exposed scrambling look very poor (6/100). Rain during the climbing period is likely to leave rock wet and more slippery. The mapped summit rock is Leucogranite (Mullach Nan Coirean Pluton). Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery. Representative samples along available mapped routes also include Pelite and calcsilicate-rock, Metaquartz-arenite and 1 other mapped type, so rock character and wet-weather behaviour may change across the mountain. Gusts may reach about 40 mph. Crosswinds can make exposed ridges substantially more serious.

Rock surfaceWet rock likelyPeak gust38 mphRain5.9 mm
Main factorsgusts around 40 mphwet rock likely
Mapped rock across the summit and available routes Leucogranite Mullach Nan Coirean Pluton
Origin
Igneous
Rock family
Granite, gneiss or gabbro
Mapping
BGS Geology 50K · 1:50,000
Rock-response profile
Moderate confidence
View the summit BGS record

Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery. Summit-point mapping plus representative BGS bedrock samples along available GPX routes. These are not continuous geological surveys; contacts, superficial deposits and the exposed rock on individual holds may differ.

Rock groups along the sampled routes

These are mapped rock groups, not separate weather forecasts or a ranking of route safety.

Stob Bàn (Mamores) and Mullach nan Coirean

psammite, pelite or semipelite, sandstone or gritstone, granite, gneiss or gabbro

Geological detail and BGS records
Mapped variation

4 rock types appear across the available route samples

The summit type remains the forecast's cautious rock-response reference. Other mapped types show where conditions may behave differently elsewhere on the mountain.

Summit mapping Leucogranite Mullach Nan Coirean Pluton Around 637 m Seen on Stob Bàn (Mamores) and Mullach nan Coirean

Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery.

BGS record
Route sample Pelite and calcsilicate-rock Leven Schist Formation 171–521 m samples Seen on Stob Bàn (Mamores) and Mullach nan Coirean

Dry quartz-rich bands can be grippy, while mica-rich or foliated sections, lichen and vegetation may become slippery when wet.

BGS record
Route sample Metaquartz-arenite Glen Coe Quartzite Member 874–989 m samples Seen on Stob Bàn (Mamores) and Mullach nan Coirean

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.

BGS record
Route sample Porphyritic microdiorite Ben Nevis Dyke Swarm Around 52 m Seen on Stob Bàn (Mamores) and Mullach nan Coirean

Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery.

BGS record

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 Mullach nan Coirean 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

Confidence: Unavailable
Overall hill weather90/100Excellent
Wind10-20 mph southerly Gusts20-30 mph Feels like-2 to 2°C PrecipitationLittle or none Cloud-free summit estimate95% Freezing levelAbove summit DaylightSunrise 07:16 · Sunset 19:04 · 11.8 hours daylight

The day on the hill

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

Cloud & views

Cloud base around 1500–1800 m in the morning, then around 2000–2300 m around midday and 1800–2100 m by late afternoon. The summit is likely to stay mostly clear.

Rain & temperature

The ground is likely to be saturated after recent rain. Expect boggy paths and rapid runoff if more rain arrives.

Little or no rain is forecast. Cold on exposed tops: air temperature broadly 2 to 6°C, feeling around -2 to 2°C in the wind.

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. Keep windproof and warm layers readily available.

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

Sunshine context Model-grid estimate, not summit sunshine

The surrounding model grid indicates 5.9 h of sunshine. This is not a forecast of time in sunshine on the summit. Use the cloud and views outlook above for the conditions on this mountain.

Early
1.7 h
Midday
2.6 h
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 10-20 mph. Gusts around 20-30 mph are possible on exposed ground.
88/100
Afternoon · 12:00–17:00 Excellent Summit winds around 10-20 mph. Gusts around 15-25 mph are possible on exposed ground. Some forecast models bring rain during the afternoon, while others keep it mostly dry.
91/100

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

Overnight · 17:00–08:00Wild campingBetaExposed camping is not recommended near 600 and 900 m: gusts may reach about 50 mph. Sustained winds may reach about 35 mph at times. Choose an alternative off the exposed hill. Do not rely on finding shelter after setting out. 19/100Poor · 600 m View detailsHide details
Night beginning Monday 28 September 2026

Full overnight outlook

Exposed camping is not recommended near 600 and 900 m: gusts may reach about 50 mph. Sustained winds may reach about 35 mph at times. Choose an alternative off the exposed hill. Do not rely on finding shelter after setting out. Open-hillside camping looks very poor overall around 600 m (19/100). Peak gusts range from about 35 mph at 300 m to 50 mph at 900 m. Around 1.1 mm is forecast, including rain around pack-up. Pitches near 900 m may spend part of the night in cloud, bringing damp conditions and poor visibility while cloud is present. The coldest temperature falls from about 7.1°C at 300 m to 5°C at 900 m.

Overnight rain1.1 mm Open ground · 600 m16 mph · gusts 43 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 4°C or lower

Moon overnight

Waning gibbous moon

Illuminated disc
94%
Moonrise
18:56 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: 28 Sep, 17:00 BST to 29 Sep, 08:00 BST. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.

Elevation reference (open ground)

300 m39/100 · poor
Wind / gust
14 mph / 37 mph
Typical / low
8.7°C / 7.1°C · much of the night
In cloud
0% of modelled night
Condensation
Low
600 m19/100 · very poor
Wind / gust
16 mph / 43 mph
Typical / low
7.7°C / 7.1°C · much of the night
In cloud
0% of modelled night
Condensation
Low
900 m9/100 · very poor
Wind / gust
19 mph / 50 mph
Typical / low
5.5°C / 5.0°C · a brief spell
In cloud
53% 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 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.

The ground is likely to be very wet after recent rain. Expect boggy approaches and choose a durable pitch carefully.

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. Good75/100 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Conditions for exposed scrambling look good (75/100). Recent rain may leave seepage and damp rock, especially on shaded sections. The mapped summit rock is Leucogranite (Mullach Nan Coirean Pluton). Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery. Representative samples along available mapped routes also include Pelite and calcsilicate-rock, Metaquartz-arenite and 1 other mapped type, so rock character and wet-weather behaviour may change across the mountain.

Rock surfaceDry overhead; seepage uncertainPeak gust24 mphRain0.0 mm
Main concerndamp or incompletely dried rock possible
Mapped rock across the summit and available routes Leucogranite Mullach Nan Coirean Pluton
Origin
Igneous
Rock family
Granite, gneiss or gabbro
Mapping
BGS Geology 50K · 1:50,000
Rock-response profile
Moderate confidence
View the summit BGS record

Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery. Summit-point mapping plus representative BGS bedrock samples along available GPX routes. These are not continuous geological surveys; contacts, superficial deposits and the exposed rock on individual holds may differ.

Rock groups along the sampled routes

These are mapped rock groups, not separate weather forecasts or a ranking of route safety.

Stob Bàn (Mamores) and Mullach nan Coirean

psammite, pelite or semipelite, sandstone or gritstone, granite, gneiss or gabbro

Geological detail and BGS records
Mapped variation

4 rock types appear across the available route samples

The summit type remains the forecast's cautious rock-response reference. Other mapped types show where conditions may behave differently elsewhere on the mountain.

Summit mapping Leucogranite Mullach Nan Coirean Pluton Around 637 m Seen on Stob Bàn (Mamores) and Mullach nan Coirean

Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery.

BGS record
Route sample Pelite and calcsilicate-rock Leven Schist Formation 171–521 m samples Seen on Stob Bàn (Mamores) and Mullach nan Coirean

Dry quartz-rich bands can be grippy, while mica-rich or foliated sections, lichen and vegetation may become slippery when wet.

BGS record
Route sample Metaquartz-arenite Glen Coe Quartzite Member 874–989 m samples Seen on Stob Bàn (Mamores) and Mullach nan Coirean

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.

BGS record
Route sample Porphyritic microdiorite Ben Nevis Dyke Swarm Around 52 m Seen on Stob Bàn (Mamores) and Mullach nan Coirean

Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery.

BGS record

Generic exposed scrambling terrain; mapped summit-point bedrock is included where available, but route grade, exact rock, polish, drainage and escape options remain unresolved. Contains British Geological Survey materials © UKRI 2026. How to use the climbing and scrambling forecast.

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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.

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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 Mullach nan Coirean on Monday 28 September 2026. It asks about intentions, not whether you actually went out. No name or account is needed.

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Confidence: Unavailable
Overall hill weather0/100Severe hill conditions
Wind40-60 mph southerly Gusts75-85 mph Feels like-4 to 0°C PrecipitationAround 5-10 mm Cloud-free summit estimate90% Cloud base through day1,300-1,900 m Freezing levelAbove summit DaylightSunrise 07:18 · Sunset 19:01 · 11.7 hours daylight

The day on the hill

Strong gusts on Mullach nan Coirean: summit wind broadly 40-60 mph, with gusts 75-85 mph at times (storm-force mean winds at times).

Wind & exposure

Much calmer lower down - generally 10-20 mph in the valley, rising towards the tops.

Cloud & views

Cloud base around 1300–1600 m in the morning, lifting to 1400–1700 m around midday and 1600–1900 m by late afternoon. The summit is likely to stay mostly clear.

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

The forecast total is around 5-10 mm, but local amounts will vary. Cold on exposed tops: air temperature broadly 4 to 8°C, feeling around -4 to 0°C in the wind.

Forecast models disagree markedly on summit wind strength. Check again nearer the time.

Keep windproof and warm layers readily available. If clothing gets wet, you can cool more quickly.

Keep a dry warm layer protected. The strongest gusts could knock you over on exposed ground.

Avoid exposed ridges and edges.

Rain & temperature

The ground is likely to be wet after recent rain.

Forecast confidence

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

0 is the bottom of the scale. Use the hazard details to judge how severe conditions could be.

Cloud-free timing: Around 55% early, improving to around 95% later.

Sunshine context Model-grid estimate, not summit sunshine

The surrounding model grid indicates 6.6 h of sunshine. This is not a forecast of time in sunshine on the summit. Use the cloud and views outlook above for the conditions on this mountain.

Early
0 h
Midday
3 h
Later
2.6 h

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

Morning · 08:00–12:00 Poor Summit winds around 30-40 mph. Gusts around 50-60 mph are possible on exposed ground. Gusts may knock you off balance on exposed ground, even between spells of lighter wind. Summit cloud is more persistent early in this period, with better prospects later. Rain is forecast during this period.
15/100
Afternoon · 12:00–17:00 Severe hill conditions Winds strengthen compared with the morning. Summit winds around 40-60 mph. Gusts around 75-85 mph are possible on exposed ground. The strongest gusts could knock you over on exposed ground. Avoid exposed ridges and edges. Rain is forecast during this period.
0/100

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

Overnight · 17:00–08:00Wild campingBetaExposed camping is not recommended near 300, 600 and 900 m: gusts may reach about 90 mph. Sustained winds may reach about 65 mph at times. Choose an alternative off the exposed hill. Do not rely on finding shelter after setting out. 0/100Poor · 600 m View detailsHide details
Night beginning Tuesday 29 September 2026

Full overnight outlook

Exposed camping is not recommended near 300, 600 and 900 m: gusts may reach about 90 mph. Sustained winds may reach about 65 mph at times. Choose an alternative off the exposed hill. Do not rely on finding shelter after setting out. Open-hillside camping looks very poor overall around 600 m (0/100). Peak gusts range from about 65 mph at 300 m to 90 mph at 900 m. Roughly 11 mm is forecast overnight, with rain liable to affect both pitching and packing up. Some condensation is possible overnight. The coldest temperature falls from about 8.5°C at 300 m to 5.7°C at 900 m.

Overnight rain11.0 mm Open ground · 600 m48 mph · gusts 76 mph Morning pack-upDampness possible Sleeping-bag warmthISO comfort rating about 6°C or lower

Moon overnight

Waning gibbous moon

Illuminated disc
87%
Moonrise
19:08 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: 29 Sep, 17:00 BST to 30 Sep, 08:00 BST. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.

Elevation reference (open ground)

300 m0/100 · very poor
Wind / gust
40 mph / 63 mph
Typical / low
9.6°C / 8.5°C · much of the night
In cloud
0% of modelled night
Condensation
Low
600 m0/100 · very poor
Wind / gust
48 mph / 76 mph
Typical / low
9.4°C / 8.0°C · much of the night
In cloud
13% of modelled night
Condensation
Low
900 m0/100 · very poor
Wind / gust
57 mph / 90 mph
Typical / low
7.5°C / 5.7°C · much of the night
In cloud
13% 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 6°C. Allow more margin if you sleep cold or expect fatigue, and use an adequate insulated mat. Dampness is possible, so keep the sleep system dry and ensure its insulation remains effective if damp.

Open-hillside reference. A sheltered pitch may be calmer; cols and ridges may be much windier. Tent design and the exact pitch still matter. Read about sleeping-bag comfort ratings, pitching in strong winds or using the wild-camping forecast.

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

Daytime · exposed rockClimbing & scramblingBetaWet rock is likely. Gusts near 80 mph may affect balance on exposed rock. Poor0/100 View detailsHide details
Generic exposed-rock guidance

Full climbing & scrambling outlook

Conditions for exposed scrambling look very poor (0/100). Rain during the climbing period is likely to leave rock wet and more slippery. The mapped summit rock is Leucogranite (Mullach Nan Coirean Pluton). Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery. Representative samples along available mapped routes also include Pelite and calcsilicate-rock, Metaquartz-arenite and 1 other mapped type, so rock character and wet-weather behaviour may change across the mountain. Gusts may reach about 80 mph. Crosswinds can make exposed ridges substantially more serious.

Rock surfaceWet rock likelyPeak gust79 mphRain7.5 mm
Main factorsgusts around 80 mphwet rock likely
Mapped rock across the summit and available routes Leucogranite Mullach Nan Coirean Pluton
Origin
Igneous
Rock family
Granite, gneiss or gabbro
Mapping
BGS Geology 50K · 1:50,000
Rock-response profile
Moderate confidence
View the summit BGS record

Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery. Summit-point mapping plus representative BGS bedrock samples along available GPX routes. These are not continuous geological surveys; contacts, superficial deposits and the exposed rock on individual holds may differ.

Rock groups along the sampled routes

These are mapped rock groups, not separate weather forecasts or a ranking of route safety.

Stob Bàn (Mamores) and Mullach nan Coirean

psammite, pelite or semipelite, sandstone or gritstone, granite, gneiss or gabbro

Geological detail and BGS records
Mapped variation

4 rock types appear across the available route samples

The summit type remains the forecast's cautious rock-response reference. Other mapped types show where conditions may behave differently elsewhere on the mountain.

Summit mapping Leucogranite Mullach Nan Coirean Pluton Around 637 m Seen on Stob Bàn (Mamores) and Mullach nan Coirean

Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery.

BGS record
Route sample Pelite and calcsilicate-rock Leven Schist Formation 171–521 m samples Seen on Stob Bàn (Mamores) and Mullach nan Coirean

Dry quartz-rich bands can be grippy, while mica-rich or foliated sections, lichen and vegetation may become slippery when wet.

BGS record
Route sample Metaquartz-arenite Glen Coe Quartzite Member 874–989 m samples Seen on Stob Bàn (Mamores) and Mullach nan Coirean

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.

BGS record
Route sample Porphyritic microdiorite Ben Nevis Dyke Swarm Around 52 m Seen on Stob Bàn (Mamores) and Mullach nan Coirean

Generally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery.

BGS record

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 Mullach nan Coirean on Tuesday 29 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: 2026-09-22

Keep exploring

Weather around Mullach nan Coirean.

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

Regional mountain forecastLochaberView area →
Stob Bàn (Mamores)999 m · 2.7 km awayForecast →Mam na Gualainn796 m · 3.8 km awayForecast →Sgùrr a' Mhàim1,099 m · 4.2 km awayForecast →Am Bodach1,032 m · 5.5 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