1,042 m summit in Perthshire Highlands. 8 forecast days covering wind, cloud, rain and temperature, updated 5 November 2026 at 16:25 UTC.
Choose your hill day.
Compare 8 days, then read the outlook for your visit. Scores start at 100 and can fall below zero in severe weather. How we score a hill day.
Select a day to replace the detailed forecast below. 8 forecast days are available here.
Confidence: High
Overall hill weather61Mixed
Summit wind · 08:00-17:0010-20 mph easterlySummit gusts · 08:00-17:0020-30 mphFeels like-8 to -4°CPrecipitationUp to around 2 mmCloud-free summit estimate10%Cloud base through day700-1,000 mFreezing levelAbove summitDaylightSunrise 07:33 · Sunset 16:25 · 8.9 hours daylight
The day on the hill
A mixed day on Càrn Mairg, with the summit in cloud for most of the day.
Wind
On the summit expect an easterly wind of 10–20 mph for most of the day, with gusts of 20–30 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 600–900 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.
Rain and ground
Drizzle sets in mid-afternoon.
Warmth and kit
On the tops it will be around -2 to 2°C, feeling like -8 to -4°C in the wind. The freezing level is above the summits. Take a hat, gloves, a windproof and a spare warm layer.
Daylight
A short day, with only about 9 hours of daylight. Sunset is around 4:25pm, so allow time to get off the hill before dark, and carry a head torch.
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 10-20 mph. Gusts around 20-30 mph are possible on exposed ground.
63
Afternoon · 12:00–17:00
MixedSummit winds around 10-20 mph. Gusts around 20-30 mph are possible on exposed ground. Rain is forecast during this period.
59
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 30 mph.59Mixed · 600 mView detailsHide details
Night beginning Thursday 5 November 2026
Full overnight outlook
A mixed night to camp, mainly because of damp air. Gusts reach about 30 mph on open ground, so peg out well and use the guylines. Look for shelter from the east. Dry to pitch, then a little rain overnight, easing by morning, though the tent may still be wet. Up around 900 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 (300-900 m), so expect heavy condensation. Leave the vents open. A cold night, down to about 2°C around 900 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
12 mph / 20 mph
Typical / low
3.9°C / 3.5°C · much of the night
In cloud
0% of modelled night
Condensation
High
600 m59 · mixed
Wind / gust
14 mph / 24 mph
Typical / low
3.9°C / 3.5°C · much of the night
In cloud
0% of modelled night
Condensation
High
900 m49 · mixed
Wind / gust
17 mph / 28 mph
Typical / low
2.4°C / 2.2°C · much of the night
In cloud
100% 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. Gusts of 20–30 mph will be noticeable on exposed ridges. Cloud on the tops may make route-finding and retreat harder. The rock around the summit is mostly psammite, a hard, sandy rock that has been squeezed and heated. It grips well when dry and is fair when wet. It is generally solid and blocky. On the usual routes up you may also cross schist, which has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. 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 gust20-30 mphRain0.6 mm
Main factorswet rock likelymuch of the route may be in cloud
Representative rock around the summit and along available routes
Gritty psammiteCarn Mairg Quartzite Formation
Origin
Metamorphic
Broad rock-response group
Psammite, pelite or semipelite
Mapping
BGS Geology 50K · 1:50,000
Summit area
Psammite, pelite or semipelite in 100% of 17 BGS samples within 350 m
Psammite is a hard, sandy rock that has been squeezed and heated. It grips well when dry and is fair when wet. It is generally solid and blocky. 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.
Rock groups along the sampled routes
These are mapped rock groups, not separate weather forecasts or a ranking of route safety.
Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
psammite, pelite or semipelite
Geological detail and BGS records
Mapped variation
4 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
Gritty psammiteCarn Mairg Quartzite Formation305–1,038 m samplesSeen on Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
Psammite is a hard, sandy rock that has been squeezed and heated. It grips well when dry and is fair when wet. It is generally solid and blocky.
BGS record →
Route sample
Calcareous peliteBen Lawers Schist Formation513–828 m samplesSeen on Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
Schist is a flaky, mica-rich rock that splits into layers. It has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. It splits easily along its layers, so flakes and ledges can be loose, and it is often grassy and vegetated.
BGS record →
Summit-area sample
Graphitic peliteBen Eagach Schist FormationAround 410 mSeen on Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
Schist is a flaky, mica-rich rock that splits into layers. It has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. It splits easily along its layers, so flakes and ledges can be loose, and it is often grassy and vegetated.
BGS record →
Summit-area sample
Graphitic peliteCarn Mairg Quartzite Formation
Schist is a flaky, mica-rich rock that splits into layers. It has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. It splits easily along its layers, so flakes and ledges can be loose, and it is often grassy and vegetated.
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 Càrn Mairg on Thursday 5 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Summit wind · 08:00-17:0010-20 mph easterlySummit gusts · 08:00-17:0020-30 mphFeels like-6 to -2°CPrecipitationUp to around 2 mmCloud-free summit estimate10%Cloud base through day600-900 mFreezing levelAbove summitDaylightSunrise 07:35 · Sunset 16:23 · 8.8 hours daylight
The day on the hill
A mixed day on Càrn Mairg, with the summit in cloud for most of the day.
Wind
On the summit expect an easterly wind of 10–20 mph for most of the day, with gusts of 20–30 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 600–900 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.
Rain and ground
Drizzle at first, clearing by 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 above the summits. Take a hat, gloves, a windproof and a spare warm layer.
Daylight
A short day, with only about 9 hours of daylight. Sunset is around 4:25pm, 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 10-20 mph. Gusts around 15-25 mph are possible on exposed ground.
66
Afternoon · 12:00–17:00
MixedSummit winds around 10-20 mph. Gusts around 20-30 mph are possible on exposed ground.
64
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: dry, with light winds.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 15 mph. It should stay dry. Up around 900 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 (300-900 m), so expect heavy condensation. Leave the vents open. A cold night, down to about 2°C around 900 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
7 mph / 11 mph
Typical / low
4.1°C / 3.9°C · much of the night
In cloud
0% of modelled night
Condensation
High
600 m59 · mixed
Wind / gust
8 mph / 13 mph
Typical / low
4.1°C / 3.9°C · much of the night
In cloud
0% of modelled night
Condensation
High
900 m54 · mixed
Wind / gust
10 mph / 15 mph
Typical / low
2.4°C / 2.2°C · much of the night
In cloud
80% 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. Gusts of 20–30 mph will be noticeable on exposed ridges. Cloud on the tops may make route-finding and retreat harder. The rock around the summit is mostly psammite, a hard, sandy rock that has been squeezed and heated. It grips well when dry and is fair when wet. It is generally solid and blocky. On the usual routes up you may also cross schist, which has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. 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 gust20-30 mphRain0.2 mm
Main factorswet rock likelymuch of the route may be in cloud
Representative rock around the summit and along available routes
Gritty psammiteCarn Mairg Quartzite Formation
Origin
Metamorphic
Broad rock-response group
Psammite, pelite or semipelite
Mapping
BGS Geology 50K · 1:50,000
Summit area
Psammite, pelite or semipelite in 100% of 17 BGS samples within 350 m
Psammite is a hard, sandy rock that has been squeezed and heated. It grips well when dry and is fair when wet. It is generally solid and blocky. 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.
Rock groups along the sampled routes
These are mapped rock groups, not separate weather forecasts or a ranking of route safety.
Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
psammite, pelite or semipelite
Geological detail and BGS records
Mapped variation
4 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
Gritty psammiteCarn Mairg Quartzite Formation305–1,038 m samplesSeen on Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
Psammite is a hard, sandy rock that has been squeezed and heated. It grips well when dry and is fair when wet. It is generally solid and blocky.
BGS record →
Route sample
Calcareous peliteBen Lawers Schist Formation513–828 m samplesSeen on Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
Schist is a flaky, mica-rich rock that splits into layers. It has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. It splits easily along its layers, so flakes and ledges can be loose, and it is often grassy and vegetated.
BGS record →
Summit-area sample
Graphitic peliteBen Eagach Schist FormationAround 410 mSeen on Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
Schist is a flaky, mica-rich rock that splits into layers. It has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. It splits easily along its layers, so flakes and ledges can be loose, and it is often grassy and vegetated.
BGS record →
Summit-area sample
Graphitic peliteCarn Mairg Quartzite Formation
Schist is a flaky, mica-rich rock that splits into layers. It has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. It splits easily along its layers, so flakes and ledges can be loose, and it is often grassy and vegetated.
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 Càrn Mairg on Friday 6 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Summit wind · 08:00-17:000-15 mph southeasterlySummit gusts · 08:00-17:005-15 mphFeels like-4 to 0°CPrecipitationUp to around 2 mmCloud-free summit estimate20%Cloud base through day700-1,400 mFreezing levelAbove summitDaylightSunrise 07:37 · Sunset 16:21 · 8.7 hours daylight
The day on the hill
A mixed day on Càrn Mairg, with the summit in cloud for most of the day.
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
Expect the summit to be in cloud for most of the day. The cloud base could be as low as 600–900 m around midday. 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 2am.
Rain and ground
A little rain at times.
Warmth and kit
On the tops it will be around 0 to 4°C, feeling like -4 to 0°C in the wind. The freezing level is close to summit height. Take a hat, gloves, a windproof and a spare warm layer.
Daylight
A short day, with only about 9 hours of daylight. Sunset is around 4:20pm, 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 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
GoodSummit winds around 0-10 mph. Gusts around 5-15 mph are possible on exposed ground. Summit cloud becomes more persistent later.
72
Afternoon · 12:00–17:00
MixedSummit winds around 5-15 mph. Gusts around 5-15 mph are possible on exposed ground.
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: 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 damp air. Light winds on open ground, gusting no more than about 15 mph. It should stay dry. Up around 900 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 up around 900 m, so expect heavy condensation. Leave the vents open. A cold night, down to about 2°C around 900 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.
Mixed conditions for exposed scrambling. The rock should be drying, but damp patches, shaded holds and drainage lines may still be wet. Cloud on the tops may make route-finding and retreat harder. The rock around the summit is mostly psammite, a hard, sandy rock that has been squeezed and heated. It grips well when dry and is fair when wet. It is generally solid and blocky. On the usual routes up you may also cross schist, which has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. 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 gust5-15 mphRain0.2 mm
Main factorsdamp or incompletely dried rock possiblemuch of the route may be in cloud
Representative rock around the summit and along available routes
Gritty psammiteCarn Mairg Quartzite Formation
Origin
Metamorphic
Broad rock-response group
Psammite, pelite or semipelite
Mapping
BGS Geology 50K · 1:50,000
Summit area
Psammite, pelite or semipelite in 100% of 17 BGS samples within 350 m
Psammite is a hard, sandy rock that has been squeezed and heated. It grips well when dry and is fair when wet. It is generally solid and blocky. 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.
Rock groups along the sampled routes
These are mapped rock groups, not separate weather forecasts or a ranking of route safety.
Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
psammite, pelite or semipelite
Geological detail and BGS records
Mapped variation
4 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
Gritty psammiteCarn Mairg Quartzite Formation305–1,038 m samplesSeen on Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
Psammite is a hard, sandy rock that has been squeezed and heated. It grips well when dry and is fair when wet. It is generally solid and blocky.
BGS record →
Route sample
Calcareous peliteBen Lawers Schist Formation513–828 m samplesSeen on Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
Schist is a flaky, mica-rich rock that splits into layers. It has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. It splits easily along its layers, so flakes and ledges can be loose, and it is often grassy and vegetated.
BGS record →
Summit-area sample
Graphitic peliteBen Eagach Schist FormationAround 410 mSeen on Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
Schist is a flaky, mica-rich rock that splits into layers. It has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. It splits easily along its layers, so flakes and ledges can be loose, and it is often grassy and vegetated.
BGS record →
Summit-area sample
Graphitic peliteCarn Mairg Quartzite Formation
Schist is a flaky, mica-rich rock that splits into layers. It has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. It splits easily along its layers, so flakes and ledges can be loose, and it is often grassy and vegetated.
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 Càrn Mairg on Saturday 7 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Summit wind · 08:00-17:000-10 mph easterlySummit gusts · 08:00-17:005-15 mphFeels like-4 to 0°CPrecipitationLittle or noneCloud-free summit estimate45%Cloud base through day800-1,500 mFreezing levelAbove summitDaylightSunrise 07:40 · Sunset 16:19 · 8.7 hours daylight
The day on the hill
A good day on Càrn Mairg, though expect cloud on the tops early.
Wind
On the summit expect light winds of up to 10 mph, mainly easterly, with gusts of 5–15 mph at the windiest.
Cloud and visibility
Cloud on the tops early should lift off them by midday. The cloud base could be as low as 700–1000 m around midday. A few forecast models bring it lower still, to around 500–800 m.
Rain and ground
It should stay dry.
Warmth and kit
On the tops it will be around 0 to 4°C, feeling like -4 to 0°C in the wind. The freezing level is close to summit height. Take a hat, gloves, a windproof and a spare warm layer.
Daylight
A short day, with only about 9 hours of daylight. Sunset is around 4:20pm, 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 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 3.4 h of sunshine. This is not a forecast of time in sunshine on the summit. Use the cloud and views outlook above for the conditions on this mountain.
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.
66
Afternoon · 12:00–17:00
ExcellentSummit 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.
89
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: dry, with light winds.59Mixed · 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 9 mph. It should stay dry. The air is damp below about 600 m, so expect heavy condensation. Leave the vents open. A cold night, down to about 2°C around 900 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.
Good conditions for exposed scrambling. The rock should be mostly dry, though drainage lines and shaded holds may still be damp. Cloud on the tops may make route-finding and retreat harder. The rock around the summit is mostly psammite, a hard, sandy rock that has been squeezed and heated. It grips well when dry and is fair when wet. It is generally solid and blocky. On the usual routes up you may also cross schist, which has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. 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 gust5-15 mphRain0.0 mm
Representative rock around the summit and along available routes
Gritty psammiteCarn Mairg Quartzite Formation
Origin
Metamorphic
Broad rock-response group
Psammite, pelite or semipelite
Mapping
BGS Geology 50K · 1:50,000
Summit area
Psammite, pelite or semipelite in 100% of 17 BGS samples within 350 m
Psammite is a hard, sandy rock that has been squeezed and heated. It grips well when dry and is fair when wet. It is generally solid and blocky. 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.
Rock groups along the sampled routes
These are mapped rock groups, not separate weather forecasts or a ranking of route safety.
Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
psammite, pelite or semipelite
Geological detail and BGS records
Mapped variation
4 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
Gritty psammiteCarn Mairg Quartzite Formation305–1,038 m samplesSeen on Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
Psammite is a hard, sandy rock that has been squeezed and heated. It grips well when dry and is fair when wet. It is generally solid and blocky.
BGS record →
Route sample
Calcareous peliteBen Lawers Schist Formation513–828 m samplesSeen on Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
Schist is a flaky, mica-rich rock that splits into layers. It has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. It splits easily along its layers, so flakes and ledges can be loose, and it is often grassy and vegetated.
BGS record →
Summit-area sample
Graphitic peliteBen Eagach Schist FormationAround 410 mSeen on Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
Schist is a flaky, mica-rich rock that splits into layers. It has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. It splits easily along its layers, so flakes and ledges can be loose, and it is often grassy and vegetated.
BGS record →
Summit-area sample
Graphitic peliteCarn Mairg Quartzite Formation
Schist is a flaky, mica-rich rock that splits into layers. It has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. It splits easily along its layers, so flakes and ledges can be loose, and it is often grassy and vegetated.
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 Càrn Mairg on Sunday 8 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Summit wind · 08:00-17:005-15 mph easterlySummit gusts · 08:00-17:0010-20 mphFeels like-8 to -4°CPrecipitationLittle or noneCloud-free summit estimate65%Cloud base through day700-1,300 mFreezing level900-1,200 mDaylightSunrise 07:42 · Sunset 16:17 · 8.6 hours daylight
The day on the hill
Dry, with light winds on Càrn Mairg. Cloud could cover the tops and limit the views.
Wind
On the summit expect light winds of up to 15 mph, mainly easterly, 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
Clear spells are possible, but cloud could cover the tops for part of the day. Forecast models differ on how much summit cloud develops. A few forecast models bring the cloud base down to around 500–800 m at times. The cloud base sits close to summit height, so the top could go in and out of cloud at short notice. Mist or fog is possible in the valleys early on, clearing by about 1am.
Rain and ground
It should stay dry.
Warmth and kit
On the tops it will be around -4 to 0°C, feeling like -8 to -4°C in the wind. The freezing level is close to summit height. Take a hat, gloves, a windproof and a spare warm layer.
Daylight
A short day, with only about 9 hours of daylight. Sunset is around 4:15pm, 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 4.9 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.
Morning · 08:00–12:00
GoodSummit winds around 5-15 mph. Gusts around 10-20 mph are possible on exposed ground.
76
Afternoon · 12:00–17:00
ExcellentSummit winds around 5-15 mph. Gusts around 10-20 mph are possible on exposed ground. Summit cloud becomes more persistent later.
90
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: dry, with light winds.59Mixed · 600 mView detailsHide details
Night beginning Monday 9 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 20 mph. It should stay dry. Up around 900 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 (300-900 m), so expect heavy condensation. Leave the vents open. A cold night, down to about 1°C around 900 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.
Fair conditions for exposed scrambling. The rock should be mostly dry, though drainage lines and shaded holds may still be damp. Cloud on the tops may make route-finding and retreat harder. The rock around the summit is mostly psammite, a hard, sandy rock that has been squeezed and heated. It grips well when dry and is fair when wet. It is generally solid and blocky. On the usual routes up you may also cross schist, which has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. 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 gust10-20 mphRain0.0 mm
Representative rock around the summit and along available routes
Gritty psammiteCarn Mairg Quartzite Formation
Origin
Metamorphic
Broad rock-response group
Psammite, pelite or semipelite
Mapping
BGS Geology 50K · 1:50,000
Summit area
Psammite, pelite or semipelite in 100% of 17 BGS samples within 350 m
Psammite is a hard, sandy rock that has been squeezed and heated. It grips well when dry and is fair when wet. It is generally solid and blocky. 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.
Rock groups along the sampled routes
These are mapped rock groups, not separate weather forecasts or a ranking of route safety.
Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
psammite, pelite or semipelite
Geological detail and BGS records
Mapped variation
4 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
Gritty psammiteCarn Mairg Quartzite Formation305–1,038 m samplesSeen on Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
Psammite is a hard, sandy rock that has been squeezed and heated. It grips well when dry and is fair when wet. It is generally solid and blocky.
BGS record →
Route sample
Calcareous peliteBen Lawers Schist Formation513–828 m samplesSeen on Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
Schist is a flaky, mica-rich rock that splits into layers. It has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. It splits easily along its layers, so flakes and ledges can be loose, and it is often grassy and vegetated.
BGS record →
Summit-area sample
Graphitic peliteBen Eagach Schist FormationAround 410 mSeen on Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
Schist is a flaky, mica-rich rock that splits into layers. It has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. It splits easily along its layers, so flakes and ledges can be loose, and it is often grassy and vegetated.
BGS record →
Summit-area sample
Graphitic peliteCarn Mairg Quartzite Formation
Schist is a flaky, mica-rich rock that splits into layers. It has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. It splits easily along its layers, so flakes and ledges can be loose, and it is often grassy and vegetated.
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 Càrn Mairg on Monday 9 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Summit wind · 08:00-17:0010-25 mph southeasterlySummit gusts · 08:00-17:0020-30 mphFeels like-8 to -4°CPrecipitationLittle or noneCloud-free summit estimate30%Cloud base through day500-800 mFreezing level900-1,200 mDaylightSunrise 07:44 · Sunset 16:15 · 8.5 hours daylight
The day on the hill
A mixed day on Càrn Mairg, with snow on the tops and cloud coming and going on the summit.
Snow and navigation
Snow is forecast on the tops in the morning. The air freezing level is roughly 1000 to 1100 m above sea level. Snow can fall below this, but its lower limit is uncertain.
Wind
On the summit expect a south-easterly wind of 10–25 mph for most of the day, with gusts of 20–30 mph at the windiest. Lower down on the open hillside the wind will be light, under 10 mph. A wind like that will be noticeable on ridges and open tops, and you will chill quickly when you stop.
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 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.
Rain and ground
Mostly dry, but some forecast models bring rain in the afternoon.
Warmth and kit
On the tops it will be around -2 to 2°C, feeling like -8 to -4°C in the wind. The freezing level is close to summit height. Take a hat, gloves, a windproof and a spare warm layer. Pack waterproofs too, and keep a warm layer dry in your pack.
Daylight
A short day, with only about 9 hours of daylight. Sunset is around 4:15pm, so allow time to get off the hill before dark, and carry a head torch.
Forecast confidence
The forecast models disagree on how strong the wind will be, so it could be noticeably stronger than this. 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 2.1 h of sunshine. This is not a forecast of time in sunshine on the summit. Use the cloud and views outlook above for the conditions on this mountain.
Cloud may obscure this summit even while the surrounding model grid indicates sunshine. The low cloud-free summit estimate is a reason to be cautious about expecting views.
Morning · 08:00–12:00
MixedSummit winds around 10-20 mph. Gusts around 20-30 mph are possible on exposed ground.
54
Afternoon · 12:00–17:00
MixedSummit winds around 15-25 mph. Gusts around 20-30 mph are possible on exposed ground. Summit cloud is more persistent early in this period, with better prospects later. Rain is possible during the afternoon, but forecast models disagree on whether it will fall.
68
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 3 mm of rain.54Mixed · 600 mView detailsHide details
Night beginning Tuesday 10 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 25 mph. The wind swings from southeasterly to northeasterly overnight, so a pitch sheltered at dusk may not be by morning. Dry to pitch, then about 3 mm of rain overnight and into the morning, so expect to pack a wet tent. Above about 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 900 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.
Very poor conditions for exposed scrambling. It should stay mostly dry, but a passing shower could leave the rock damp and slippery. Snow is likely on the rock and ledges, so it becomes a winter route. Gusts of 20–30 mph will be noticeable on exposed ridges. Cloud on the tops may make route-finding and retreat harder. The rock around the summit is mostly psammite, a hard, sandy rock that has been squeezed and heated. It grips well when dry and is fair when wet. It is generally solid and blocky. On the usual routes up you may also cross schist, which has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. 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 gust20-30 mphRainPossible · 38%
Main factorsrain possible despite mostly dry conditions being favouredmuch of the route may be in cloudSnow may fall on high ground. Deposits could make summer scrambling conditions inappropriate
Representative rock around the summit and along available routes
Gritty psammiteCarn Mairg Quartzite Formation
Origin
Metamorphic
Broad rock-response group
Psammite, pelite or semipelite
Mapping
BGS Geology 50K · 1:50,000
Summit area
Psammite, pelite or semipelite in 100% of 17 BGS samples within 350 m
Psammite is a hard, sandy rock that has been squeezed and heated. It grips well when dry and is fair when wet. It is generally solid and blocky. 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.
Rock groups along the sampled routes
These are mapped rock groups, not separate weather forecasts or a ranking of route safety.
Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
psammite, pelite or semipelite
Geological detail and BGS records
Mapped variation
4 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
Gritty psammiteCarn Mairg Quartzite Formation305–1,038 m samplesSeen on Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
Psammite is a hard, sandy rock that has been squeezed and heated. It grips well when dry and is fair when wet. It is generally solid and blocky.
BGS record →
Route sample
Calcareous peliteBen Lawers Schist Formation513–828 m samplesSeen on Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
Schist is a flaky, mica-rich rock that splits into layers. It has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. It splits easily along its layers, so flakes and ledges can be loose, and it is often grassy and vegetated.
BGS record →
Summit-area sample
Graphitic peliteBen Eagach Schist FormationAround 410 mSeen on Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
Schist is a flaky, mica-rich rock that splits into layers. It has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. It splits easily along its layers, so flakes and ledges can be loose, and it is often grassy and vegetated.
BGS record →
Summit-area sample
Graphitic peliteCarn Mairg Quartzite Formation
Schist is a flaky, mica-rich rock that splits into layers. It has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. It splits easily along its layers, so flakes and ledges can be loose, and it is often grassy and vegetated.
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 Càrn Mairg on Tuesday 10 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Dry, with light winds on Càrn Mairg. Cloud could cover the tops and limit the views.
Wind
On the summit expect a northerly wind of 5–20 mph for most of the day, with gusts of 20–30 mph at the windiest. Lower down on the open hillside the wind will be light, under 10 mph. It gets windier still after dark, with summit gusts of 20–30 mph, so bear that in mind if you will be out late.
Cloud and visibility
Clear spells are possible, but cloud could cover the tops for part of the day. Forecast models differ on how much summit cloud develops. A few forecast models bring the cloud base down to around 400–700 m at times.
Rain and ground
It should stay dry.
Warmth and kit
On the tops it will be around -2 to 2°C, feeling like -8 to -4°C in the wind. The freezing level falls through the day, to around 1000–1300 m by early afternoon. Take a hat, gloves, a windproof and a spare warm layer.
Daylight
A short day, with only about 8 hours of daylight. Sunset is around 4:15pm, 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 7.9 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.
Morning · 08:00–12:00
ExcellentSummit winds around 5-15 mph. Gusts around 15-25 mph are possible on exposed ground.
100
Afternoon · 12:00–17:00
ExcellentSummit winds around 10-20 mph. Gusts around 20-30 mph are possible on exposed ground.
89
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: a frost, down to -4°C.39Poor · 600 mView detailsHide details
Night beginning Wednesday 11 November 2026
Full overnight outlook
A poor night to camp on open ground. Gusts reach about 35 mph around 900 m and nearer 25 mph around 300 m, so peg out well and use the guylines. Look for shelter from the north. It should stay dry. A frost at every height we checked (300-900 m), down to about -4°C. A warm 3-season or 3–4 season bag rated to about -4°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 -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.
Poor conditions for exposed scrambling. The rock should be drying, but damp patches, shaded holds and drainage lines may still be wet. Icy patches are likely on the rock, which makes it treacherous without winter kit. Gusts of 20–30 mph will be noticeable on exposed ridges. The rock around the summit is mostly psammite, a hard, sandy rock that has been squeezed and heated. It grips well when dry and is fair when wet. It is generally solid and blocky. On the usual routes up you may also cross schist, which has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. 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 gust20-30 mphRain0.0 mm
Main factorsdamp or incompletely dried rock possibleSub-zero temperatures and moisture may leave icy patches on exposed rock
Representative rock around the summit and along available routes
Gritty psammiteCarn Mairg Quartzite Formation
Origin
Metamorphic
Broad rock-response group
Psammite, pelite or semipelite
Mapping
BGS Geology 50K · 1:50,000
Summit area
Psammite, pelite or semipelite in 100% of 17 BGS samples within 350 m
Psammite is a hard, sandy rock that has been squeezed and heated. It grips well when dry and is fair when wet. It is generally solid and blocky. 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.
Rock groups along the sampled routes
These are mapped rock groups, not separate weather forecasts or a ranking of route safety.
Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
psammite, pelite or semipelite
Geological detail and BGS records
Mapped variation
4 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
Gritty psammiteCarn Mairg Quartzite Formation305–1,038 m samplesSeen on Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
Psammite is a hard, sandy rock that has been squeezed and heated. It grips well when dry and is fair when wet. It is generally solid and blocky.
BGS record →
Route sample
Calcareous peliteBen Lawers Schist Formation513–828 m samplesSeen on Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
Schist is a flaky, mica-rich rock that splits into layers. It has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. It splits easily along its layers, so flakes and ledges can be loose, and it is often grassy and vegetated.
BGS record →
Summit-area sample
Graphitic peliteBen Eagach Schist FormationAround 410 mSeen on Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
Schist is a flaky, mica-rich rock that splits into layers. It has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. It splits easily along its layers, so flakes and ledges can be loose, and it is often grassy and vegetated.
BGS record →
Summit-area sample
Graphitic peliteCarn Mairg Quartzite Formation
Schist is a flaky, mica-rich rock that splits into layers. It has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. It splits easily along its layers, so flakes and ledges can be loose, and it is often grassy and vegetated.
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 Càrn Mairg on Wednesday 11 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Dry and breezy on Càrn Mairg, with a bitter wind chill. Cloud could cover the tops and limit the views.
Wind
On the summit expect a northerly wind of 20–30 mph for most of the day, with gusts of 25–35 mph at the windiest. Lower down on the open hillside the wind will be light, under 10 mph. Gusts like that will be noticeable on ridges and open tops, and you will chill quickly when you stop.
Cloud and visibility
Clear spells are possible, but cloud could cover the tops for part of the day. Forecast models differ on how much summit cloud develops.
Rain and ground
It should stay dry.
Warmth and kit
On the tops it will be around -6 to -2°C, feeling like -16 to -12°C in the wind. The freezing level is around 400–700 m, so it will be below freezing on the tops. Hat, gloves and a warm insulated layer are essential, with extra warmth for stops.
Daylight
A short day, with only about 8 hours of daylight. Sunset is around 4:10pm, 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 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.
Morning · 08:00–12:00
GoodSummit winds around 20-30 mph. Gusts around 25-35 mph are possible on exposed ground.
70
Afternoon · 12:00–17:00
GoodSummit winds around 20-30 mph. Gusts around 25-35 mph are possible on exposed ground.
71
Compare an early start with later conditions. The main forecast above covers the day in more detail.
Overnight · 17:00–08:00Wild campingBetaToo windy for an exposed pitch up around 900 m (gusts of about 45 mph and a frost, down to -5°C). Lower down, a poor night to camp on open ground.39Poor · 600 mView detailsHide details
Night beginning Thursday 12 November 2026
Full overnight outlook
Too windy for an exposed pitch up around 900 m. Lower down, a poor night to camp on open ground. Gusts reach about 45 mph around 900 m and nearer 30 mph around 300 m, enough to damage a tent on open ground. Pitch low down and in real shelter, or leave it for another night. It should stay dry. A frost at every height we checked (300-900 m), down to about -5°C. A 4-season bag rated to about -6°C comfort, and a warm mat, should do. Allow more if you sleep cold.
Clear spells may allow a view of the Moon. Illumination describes the sunlit part of the Moon, not brightness at your pitch.
Overnight window: 12 Nov, 17:00 GMT to 13 Nov, 08:00 GMT. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.
Elevation reference (open ground)
300 m39 · poor
Wind / gust
22 mph / 31 mph
Typical / low
-2.7°C / -3.1°C · much of the night
In cloud
0% of modelled night
Condensation
Low
600 m39 · poor
Wind / gust
26 mph / 38 mph
Typical / low
-2.7°C / -3.1°C · much of the night
In cloud
0% of modelled night
Condensation
Low
900 m19 · very poor
Wind / gust
31 mph / 45 mph
Typical / low
-4.7°C / -5.2°C · much of the night
In cloud
0% of modelled night
Condensation
Low
Warmth planning: As a broad starting point, consider a 4-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.
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 25–35 mph.Good70View detailsHide details
Generic exposed-rock guidance
Full climbing & scrambling outlook
Fair conditions for exposed scrambling. The rock should be mostly dry, though drainage lines and shaded holds may still be damp. Gusts of 25–35 mph could throw you off balance on exposed moves and ridges. The rock around the summit is mostly psammite, a hard, sandy rock that has been squeezed and heated. It grips well when dry and is fair when wet. It is generally solid and blocky. On the usual routes up you may also cross schist, which has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. 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 gust25-35 mphRain0.0 mm
Main concerngusts of 25–35 mph
Representative rock around the summit and along available routes
Gritty psammiteCarn Mairg Quartzite Formation
Origin
Metamorphic
Broad rock-response group
Psammite, pelite or semipelite
Mapping
BGS Geology 50K · 1:50,000
Summit area
Psammite, pelite or semipelite in 100% of 17 BGS samples within 350 m
Psammite is a hard, sandy rock that has been squeezed and heated. It grips well when dry and is fair when wet. It is generally solid and blocky. 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.
Rock groups along the sampled routes
These are mapped rock groups, not separate weather forecasts or a ranking of route safety.
Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
psammite, pelite or semipelite
Geological detail and BGS records
Mapped variation
4 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
Gritty psammiteCarn Mairg Quartzite Formation305–1,038 m samplesSeen on Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
Psammite is a hard, sandy rock that has been squeezed and heated. It grips well when dry and is fair when wet. It is generally solid and blocky.
BGS record →
Route sample
Calcareous peliteBen Lawers Schist Formation513–828 m samplesSeen on Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
Schist is a flaky, mica-rich rock that splits into layers. It has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. It splits easily along its layers, so flakes and ledges can be loose, and it is often grassy and vegetated.
BGS record →
Summit-area sample
Graphitic peliteBen Eagach Schist FormationAround 410 mSeen on Càrn Gorm, Meall Garbh (Càrn Mairg), Càrn Mairg and Creag Mhòr (Meall na Aighean)
Schist is a flaky, mica-rich rock that splits into layers. It has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. It splits easily along its layers, so flakes and ledges can be loose, and it is often grassy and vegetated.
BGS record →
Summit-area sample
Graphitic peliteCarn Mairg Quartzite Formation
Schist is a flaky, mica-rich rock that splits into layers. It has only fair grip when dry and is slippery when wet, as the mica gives it a greasy sheen. It splits easily along its layers, so flakes and ledges can be loose, and it is often grassy and vegetated.
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 Càrn Mairg on Thursday 12 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Càrn Mairg is one of Scotland’s 282 Munros. Munro Planner compares all 282 by forecast, summit views and drive time, with walking routes, times and OS map references for each hill.
