1,148 m summit in Lochaber. 8 forecast days covering wind, cloud, rain and temperature, updated 4 November 2026 at 16:25 UTC.
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Confidence: Medium
Overall hill weather84Good
Summit wind · 08:00-17:005-15 mph southeasterlySummit gusts · 08:00-17:0010-20 mphFeels like-6 to -2°CPrecipitationLittle or noneCloud-free summit estimate65%Cloud base through day700-1,600 mFreezing levelAbove summitDaylightSunrise 07:33 · Sunset 16:28 · 8.9 hours daylight
The day on the hill
A good day on Ben Alder: dry, with light winds.
Wind
On the summit expect light winds of up to 15 mph, mainly south-easterly, with gusts of 10–20 mph at the windiest.
Cloud and visibility
Cloud on the tops early should lift off them by mid-morning. The cloud base could be as low as 700–1000 m mid-morning. Good spells of sunshine are likely. The air should be clear, so expect far-reaching views whenever the tops come out of the cloud.
Rain and ground
It should stay dry.
Warmth and kit
On the tops it will be around -2 to 2°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 4:30pm, so allow time to get off the hill before dark, and carry a head torch.
Forecast confidence
Cloud height is hard to pin down, so the summit could be in or out of cloud at short notice. Things could still change through the day, so keep an eye on the sky.
Sunshine context Model-grid estimate, not summit sunshine
The surrounding model grid indicates 6.3 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. Summit cloud is more persistent early in this period, with better prospects later.
74
Afternoon · 12:00–17:00
ExcellentSummit winds around 5-15 mph. Gusts around 10-20 mph are possible on exposed ground.
95
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 Wednesday 4 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 25 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.
Extensive cloud may limit moonlight. Illumination describes the sunlit part of the Moon, not brightness at your pitch.
Overnight window: 4 Nov, 17:00 GMT to 5 Nov, 08:00 GMT. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.
Elevation reference (open ground)
300 m59 · mixed
Wind / gust
9 mph / 16 mph
Typical / low
3.6°C / 3.4°C · much of the night
In cloud
0% of modelled night
Condensation
High
600 m59 · mixed
Wind / gust
11 mph / 20 mph
Typical / low
3.6°C / 3.4°C · much of the night
In cloud
0% of modelled night
Condensation
High
900 m54 · mixed
Wind / gust
13 mph / 23 mph
Typical / low
2.2°C / 2.1°C · much of the night
In cloud
93% 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.
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 micaceous psammite, a hard, sandy rock flecked with mica. It grips well when dry and can be slippery when wet where the mica shows. It is generally solid and blocky. On the usual routes up you may also cross gneiss, which grips very well when dry and stays reasonably grippy when wet. 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
Micaceous psammiteCreag Dhubh Psammite 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
Micaceous psammite is a hard, sandy rock flecked with mica. It grips well when dry and can be slippery when wet where the mica shows. 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.
Ben Alder and Beinn Bheoil
psammite, pelite or semipelite
Geological detail and BGS records
Mapped variation
3 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
Micaceous psammiteCreag Dhubh Psammite Formation535–1,130 m samplesSeen on Ben Alder and Beinn Bheoil
Micaceous psammite is a hard, sandy rock flecked with mica. It grips well when dry and can be slippery when wet where the mica shows. It is generally solid and blocky.
BGS record →
Route sample
Gneissose semipeliteCoire nan Laogh Semipelite FormationAround 798 mSeen on Ben Alder and Beinn Bheoil
Gneiss is a very old, hard, banded rock. It grips very well when dry and stays reasonably grippy when wet. It is usually very solid.
BGS record →
Route sample
Gneissose semipeliteFalls of Phones Semipelite FormationAround 960 mSeen on Ben Alder and Beinn Bheoil
Gneiss is a very old, hard, banded rock. It grips very well when dry and stays reasonably grippy when wet. It is usually very solid.
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 Ben Alder on Wednesday 4 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Summit wind · 08:00-17:0015-25 mph southeasterlySummit gusts · 08:00-17:0020-30 mphFeels like-8 to -4°CPrecipitationUp to around 2 mmCloud-free summit estimate10%Cloud base through day600-900 mFreezing levelAbove summitDaylightSunrise 07:35 · Sunset 16:26 · 8.8 hours daylight
The day on the hill
A mixed day on Ben Alder, with the summit in cloud for most of the day.
Wind
On the summit expect a south-easterly wind of 15–25 mph for most of the day, with gusts of 20–30 mph at the windiest. Lower down on the open hillside it will be more like 5–15 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 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
Rain arrives mid-afternoon.
Warmth and kit
On the tops it will be around 0 to 4°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 4:25pm, so allow time to get off the hill before dark, and carry a head torch.
Forecast confidence
There is some disagreement between forecast models on wind strength. 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 15-25 mph. Gusts around 20-30 mph are possible on exposed ground.
57
Afternoon · 12:00–17:00
MixedSummit winds around 15-25 mph. Gusts around 20-30 mph are possible on exposed ground. Rain is forecast during this period.
56
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 southeast. Expect a little rain, mostly early on, so you'll likely pitch in the rain. 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
13 mph / 20 mph
Typical / low
3.9°C / 3.7°C · much of the night
In cloud
0% of modelled night
Condensation
High
600 m59 · mixed
Wind / gust
15 mph / 24 mph
Typical / low
3.9°C / 3.7°C · much of the night
In cloud
0% of modelled night
Condensation
High
900 m49 · mixed
Wind / gust
18 mph / 28 mph
Typical / low
2.4°C / 2.1°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.
Very 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 micaceous psammite, a hard, sandy rock flecked with mica. It grips well when dry and can be slippery when wet where the mica shows. It is generally solid and blocky. On the usual routes up you may also cross gneiss, which grips very well when dry and stays reasonably grippy when wet. 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 mphRain0.8 mm
Main factorswet rock likelymuch of the route may be in cloud
Representative rock around the summit and along available routes
Micaceous psammiteCreag Dhubh Psammite 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
Micaceous psammite is a hard, sandy rock flecked with mica. It grips well when dry and can be slippery when wet where the mica shows. 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.
Ben Alder and Beinn Bheoil
psammite, pelite or semipelite
Geological detail and BGS records
Mapped variation
3 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
Micaceous psammiteCreag Dhubh Psammite Formation535–1,130 m samplesSeen on Ben Alder and Beinn Bheoil
Micaceous psammite is a hard, sandy rock flecked with mica. It grips well when dry and can be slippery when wet where the mica shows. It is generally solid and blocky.
BGS record →
Route sample
Gneissose semipeliteCoire nan Laogh Semipelite FormationAround 798 mSeen on Ben Alder and Beinn Bheoil
Gneiss is a very old, hard, banded rock. It grips very well when dry and stays reasonably grippy when wet. It is usually very solid.
BGS record →
Route sample
Gneissose semipeliteFalls of Phones Semipelite FormationAround 960 mSeen on Ben Alder and Beinn Bheoil
Gneiss is a very old, hard, banded rock. It grips very well when dry and stays reasonably grippy when wet. It is usually very solid.
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 Ben Alder on Thursday 5 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Summit wind · 08:00-17:0010-25 mph southeasterlySummit gusts · 08:00-17:0020-30 mphFeels like-8 to -4°CPrecipitationUp to around 2 mmCloud-free summit estimate10%Cloud base through day600-1,200 mFreezing levelAbove summitDaylightSunrise 07:37 · Sunset 16:24 · 8.8 hours daylight
The day on the hill
A mixed day on Ben Alder, with the summit in cloud for most of the day.
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.
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 around midday.
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.
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
There is some disagreement between forecast models on wind strength. 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 1.4 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 15-25 mph. Gusts around 20-30 mph are possible on exposed ground. Rain is forecast during this period.
58
Afternoon · 12:00–17:00
MixedSummit winds around 10-20 mph. Gusts around 15-25 mph are possible on exposed ground. Rain is forecast during this period.
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: gusts of about 15 mph.59Mixed · 600 mView detailsHide details
Night beginning Friday 6 November 2026
Full overnight outlook
A mixed night to camp, mainly because of damp air. Light winds on open ground, gusting no more than about 15 mph. Expect a little rain, mostly early on, so you'll likely pitch in the rain. 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 / 12 mph
Typical / low
4.1°C / 3.0°C · much of the night
In cloud
0% of modelled night
Condensation
High
600 m59 · mixed
Wind / gust
8 mph / 15 mph
Typical / low
4.1°C / 3.0°C · much of the night
In cloud
0% of modelled night
Condensation
High
900 m54 · mixed
Wind / gust
10 mph / 17 mph
Typical / low
2.3°C / 2.2°C · much of the night
In cloud
53% 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 micaceous psammite, a hard, sandy rock flecked with mica. It grips well when dry and can be slippery when wet where the mica shows. It is generally solid and blocky. On the usual routes up you may also cross gneiss, which grips very well when dry and stays reasonably grippy when wet. 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
Micaceous psammiteCreag Dhubh Psammite 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
Micaceous psammite is a hard, sandy rock flecked with mica. It grips well when dry and can be slippery when wet where the mica shows. 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.
Ben Alder and Beinn Bheoil
psammite, pelite or semipelite
Geological detail and BGS records
Mapped variation
3 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
Micaceous psammiteCreag Dhubh Psammite Formation535–1,130 m samplesSeen on Ben Alder and Beinn Bheoil
Micaceous psammite is a hard, sandy rock flecked with mica. It grips well when dry and can be slippery when wet where the mica shows. It is generally solid and blocky.
BGS record →
Route sample
Gneissose semipeliteCoire nan Laogh Semipelite FormationAround 798 mSeen on Ben Alder and Beinn Bheoil
Gneiss is a very old, hard, banded rock. It grips very well when dry and stays reasonably grippy when wet. It is usually very solid.
BGS record →
Route sample
Gneissose semipeliteFalls of Phones Semipelite FormationAround 960 mSeen on Ben Alder and Beinn Bheoil
Gneiss is a very old, hard, banded rock. It grips very well when dry and stays reasonably grippy when wet. It is usually very solid.
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 Ben Alder on Friday 6 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Summit wind · 08:00-17:005-15 mph easterlySummit gusts · 08:00-17:0010-20 mphFeels like-6 to -2°CPrecipitationUp to around 2 mmCloud-free summit estimate10%Cloud base through day600-900 mFreezing level1,000-1,300 mDaylightSunrise 07:39 · Sunset 16:22 · 8.7 hours daylight
The day on the hill
A mixed day on Ben Alder, with the summit in cloud for most of the day.
Wind
On the summit expect light winds of up to 15 mph, mainly easterly, with gusts of 10–20 mph at the windiest. Lower down on the open hillside the wind will be light, under 5 mph.
Cloud and visibility
Expect the summit to be in cloud for most of the day. The cloud base 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. Mist or fog is possible in the valleys early on, clearing by about 10am.
Rain and ground
Drizzle sets in during the early afternoon.
Warmth and kit
On the tops it will be around -2 to 2°C, feeling like -6 to -2°C in the wind. The freezing level is close to summit height. Take a hat, gloves, a windproof and a spare warm layer.
Daylight
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 Less than 1 hour 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 5-15 mph. Gusts around 5-15 mph are possible on exposed ground.
66
Afternoon · 12:00–17:00
MixedSummit winds around 5-15 mph. Gusts around 10-20 mph are possible on exposed ground. Rain is forecast during this period.
65
Compare an early start with later conditions. The main forecast above covers the day in more detail.
Overnight · 17:00–08:00Wild campingBetaA mixed night to camp, mainly because of damp air: gusts of about 15 mph.54Mixed · 600 mView detailsHide details
Night beginning 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. Dry to pitch, then a little 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. 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 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.
Very poor conditions for exposed scrambling. The rock is likely to be wet and slippery through the day. Icy patches are likely on the rock, which makes it treacherous without winter kit. Cloud on the tops may make route-finding and retreat harder. The rock around the summit is mostly micaceous psammite, a hard, sandy rock flecked with mica. It grips well when dry and can be slippery when wet where the mica shows. It is generally solid and blocky. On the usual routes up you may also cross gneiss, which grips very well when dry and stays reasonably grippy when wet. These are general notes for each rock type, taken from geological maps around the summit, so the rock on your line may differ.
Rock surfaceWet rock likelyPeak gust10-20 mphRain0.3 mm
Main factorswet rock likelymuch of the route may be in cloudSub-zero temperatures and moisture may leave icy patches on exposed rock
Representative rock around the summit and along available routes
Micaceous psammiteCreag Dhubh Psammite 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
Micaceous psammite is a hard, sandy rock flecked with mica. It grips well when dry and can be slippery when wet where the mica shows. 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.
Ben Alder and Beinn Bheoil
psammite, pelite or semipelite
Geological detail and BGS records
Mapped variation
3 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
Micaceous psammiteCreag Dhubh Psammite Formation535–1,130 m samplesSeen on Ben Alder and Beinn Bheoil
Micaceous psammite is a hard, sandy rock flecked with mica. It grips well when dry and can be slippery when wet where the mica shows. It is generally solid and blocky.
BGS record →
Route sample
Gneissose semipeliteCoire nan Laogh Semipelite FormationAround 798 mSeen on Ben Alder and Beinn Bheoil
Gneiss is a very old, hard, banded rock. It grips very well when dry and stays reasonably grippy when wet. It is usually very solid.
BGS record →
Route sample
Gneissose semipeliteFalls of Phones Semipelite FormationAround 960 mSeen on Ben Alder and Beinn Bheoil
Gneiss is a very old, hard, banded rock. It grips very well when dry and stays reasonably grippy when wet. It is usually very solid.
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 Ben Alder 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 northerlySummit gusts · 08:00-17:005-15 mphFeels like-4 to 0°CPrecipitationUp to around 2 mmCloud-free summit estimate25%Cloud base through day500-1,000 mFreezing level1,100-1,400 mDaylightSunrise 07:42 · Sunset 16:20 · 8.6 hours daylight
The day on the hill
A mixed day on Ben Alder, with sleet or snow on the tops and cloud coming and going on the summit.
Snow and navigation
Sleet or snow is possible on the tops during the morning and afternoon, with small temperature changes affecting the mix. The air freezing level is roughly 1200 to 1400 m above sea level. Snow can fall below this, but its lower limit is uncertain.
Wind
On the summit expect light winds of up to 10 mph, mainly northerly, 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 500–800 m mid-morning. 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 10am.
Rain and ground
Spells of sleet through the day. Expect up to 2 mm in total, measured as melted water, so any snow would lie deeper.
Warmth and kit
On the tops it will be around -2 to 2°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. 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 4:20pm, so allow time to get off the hill before dark, and carry a head torch.
Forecast confidence
Cloud heights are particularly hard to pin down today. 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 Less than 1 hour 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 0-10 mph are possible on exposed ground. Rain is forecast during this period.
62
Afternoon · 12:00–17:00
MixedSummit winds around 0-10 mph. Gusts around 5-15 mph are possible on exposed ground. Rain is forecast during this period.
62
Compare an early start with later conditions. The main forecast above covers the day in more detail.
Overnight · 17:00–08:00Wild campingBetaA mixed night to camp, mainly because of 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 15 mph. It should stay dry. 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. 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.
Very poor conditions for exposed scrambling. The rock is likely to be wet and slippery through the day. Icy patches are likely on the rock, which makes it treacherous without winter kit. Cloud on the tops may make route-finding and retreat harder. The rock around the summit is mostly micaceous psammite, a hard, sandy rock flecked with mica. It grips well when dry and can be slippery when wet where the mica shows. It is generally solid and blocky. On the usual routes up you may also cross gneiss, which grips very well when dry and stays reasonably grippy when wet. 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 gust5-15 mphRain0.8 mm
Main factorswet rock likelymuch of the route may be in cloudSub-zero temperatures and moisture may leave icy patches on exposed rock
Representative rock around the summit and along available routes
Micaceous psammiteCreag Dhubh Psammite 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
Micaceous psammite is a hard, sandy rock flecked with mica. It grips well when dry and can be slippery when wet where the mica shows. 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.
Ben Alder and Beinn Bheoil
psammite, pelite or semipelite
Geological detail and BGS records
Mapped variation
3 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
Micaceous psammiteCreag Dhubh Psammite Formation535–1,130 m samplesSeen on Ben Alder and Beinn Bheoil
Micaceous psammite is a hard, sandy rock flecked with mica. It grips well when dry and can be slippery when wet where the mica shows. It is generally solid and blocky.
BGS record →
Route sample
Gneissose semipeliteCoire nan Laogh Semipelite FormationAround 798 mSeen on Ben Alder and Beinn Bheoil
Gneiss is a very old, hard, banded rock. It grips very well when dry and stays reasonably grippy when wet. It is usually very solid.
BGS record →
Route sample
Gneissose semipeliteFalls of Phones Semipelite FormationAround 960 mSeen on Ben Alder and Beinn Bheoil
Gneiss is a very old, hard, banded rock. It grips very well when dry and stays reasonably grippy when wet. It is usually very solid.
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 Ben Alder on Sunday 8 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Summit wind · 08:00-17:000-15 mph westerlySummit gusts · 08:00-17:005-15 mphFeels like-8 to -4°CPrecipitationLittle or noneCloud-free summit estimate40%Cloud base through day500-1,500 mFreezing level900-1,200 mDaylightSunrise 07:44 · Sunset 16:17 · 8.6 hours daylight
The day on the hill
A mixed day on Ben Alder, with cloud coming and going on the summit.
Wind
On the summit expect light winds of up to 10 mph, mainly westerly, with gusts of 5–15 mph at the windiest. Lower down on the open hillside the wind will be light, under 5 mph.
Cloud and visibility
Expect the summit to be in cloud for most of the day. The cloud base could be as low as 500–800 m in the early afternoon. In cloud you'll be finding your way without landmarks, so carry navigation you trust and know how to use, with a backup such as a spare battery or a map and compass. Mist or fog is possible in the valleys through the morning.
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 heights are particularly hard to pin down today. 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 6.8 h of sunshine. This is not a forecast of time in sunshine on the summit. Use the cloud and views outlook above for the conditions on this mountain.
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.
60
Afternoon · 12:00–17:00
GoodSummit winds around 5-15 mph. Gusts around 5-15 mph are possible on exposed ground. Summit cloud is more persistent early in this period, with better prospects later.
77
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.54Mixed · 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 15 mph. It should stay dry. 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. 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.
Mixed 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 micaceous psammite, a hard, sandy rock flecked with mica. It grips well when dry and can be slippery when wet where the mica shows. It is generally solid and blocky. On the usual routes up you may also cross gneiss, which grips very well when dry and stays reasonably grippy when wet. 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
Main concernmuch of the route may be in cloud
Representative rock around the summit and along available routes
Micaceous psammiteCreag Dhubh Psammite 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
Micaceous psammite is a hard, sandy rock flecked with mica. It grips well when dry and can be slippery when wet where the mica shows. 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.
Ben Alder and Beinn Bheoil
psammite, pelite or semipelite
Geological detail and BGS records
Mapped variation
3 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
Micaceous psammiteCreag Dhubh Psammite Formation535–1,130 m samplesSeen on Ben Alder and Beinn Bheoil
Micaceous psammite is a hard, sandy rock flecked with mica. It grips well when dry and can be slippery when wet where the mica shows. It is generally solid and blocky.
BGS record →
Route sample
Gneissose semipeliteCoire nan Laogh Semipelite FormationAround 798 mSeen on Ben Alder and Beinn Bheoil
Gneiss is a very old, hard, banded rock. It grips very well when dry and stays reasonably grippy when wet. It is usually very solid.
BGS record →
Route sample
Gneissose semipeliteFalls of Phones Semipelite FormationAround 960 mSeen on Ben Alder and Beinn Bheoil
Gneiss is a very old, hard, banded rock. It grips very well when dry and stays reasonably grippy when wet. It is usually very solid.
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 Ben Alder on Monday 9 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Summit wind · 08:00-17:005-15 mph northerlySummit gusts · 08:00-17:0010-20 mphFeels like-10 to -6°CPrecipitationLittle or noneCloud-free summit estimate40%Cloud base through day900-1,600 mFreezing level800-1,100 mDaylightSunrise 07:46 · Sunset 16:15 · 8.5 hours daylight
The day on the hill
A good day on Ben Alder, though expect cloud on the tops early.
Wind
On the summit expect light winds of up to 15 mph, mainly northerly, 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
Cloud on the tops early should lift off them by mid-morning. The cloud base could be as low as 500–800 m early in the morning. 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 8am.
Rain and ground
It should stay dry.
Warmth and kit
On the tops it will be around -4 to 0°C, feeling like -10 to -6°C in the wind. The freezing level is around 900–1200 m, so it will be below freezing on the tops. 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 7.1 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
GoodSummit winds around 5-15 mph. Gusts around 10-20 mph are possible on exposed ground. Summit cloud is more persistent early in this period, with better prospects later.
70
Afternoon · 12:00–17:00
ExcellentSummit winds around 5-15 mph. Gusts around 10-20 mph are possible on exposed ground.
92
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: a frost, down to 0°C.59Mixed · 600 mView detailsHide details
Night beginning Tuesday 10 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. The wind swings from northerly to easterly overnight, so a pitch sheltered at dusk may not be by morning. 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 frost up around 900 m, down to about 0°C. A warm 3-season or 3–4 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 warm 3-season or 3–4 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.
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 micaceous psammite, a hard, sandy rock flecked with mica. It grips well when dry and can be slippery when wet where the mica shows. It is generally solid and blocky. On the usual routes up you may also cross gneiss, which grips very well when dry and stays reasonably grippy when wet. 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
Micaceous psammiteCreag Dhubh Psammite 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
Micaceous psammite is a hard, sandy rock flecked with mica. It grips well when dry and can be slippery when wet where the mica shows. 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.
Ben Alder and Beinn Bheoil
psammite, pelite or semipelite
Geological detail and BGS records
Mapped variation
3 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
Micaceous psammiteCreag Dhubh Psammite Formation535–1,130 m samplesSeen on Ben Alder and Beinn Bheoil
Micaceous psammite is a hard, sandy rock flecked with mica. It grips well when dry and can be slippery when wet where the mica shows. It is generally solid and blocky.
BGS record →
Route sample
Gneissose semipeliteCoire nan Laogh Semipelite FormationAround 798 mSeen on Ben Alder and Beinn Bheoil
Gneiss is a very old, hard, banded rock. It grips very well when dry and stays reasonably grippy when wet. It is usually very solid.
BGS record →
Route sample
Gneissose semipeliteFalls of Phones Semipelite FormationAround 960 mSeen on Ben Alder and Beinn Bheoil
Gneiss is a very old, hard, banded rock. It grips very well when dry and stays reasonably grippy when wet. It is usually very solid.
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 Ben Alder on Tuesday 10 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
Summit wind · 08:00-17:005-20 mph easterlySummit gusts · 08:00-17:0015-25 mphFeels like-8 to -4°CPrecipitationLittle or noneCloud-free summit estimate35%Cloud base through day700-1,500 mFreezing level900-1,200 mDaylightSunrise 07:48 · Sunset 16:14 · 8.4 hours daylight
The day on the hill
A mixed day on Ben Alder, with cloud coming and going on the summit.
Wind
On the summit expect light winds of up to 15 mph, mainly easterly, with gusts of 15–25 mph at the windiest. Lower down on the open hillside the wind will be light, under 10 mph.
Cloud and visibility
Expect the summit to be in cloud for most of the day. The cloud base could be as low as 700–1000 m early in the morning. 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 7am.
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 is close to summit height. 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 seven days off and could change, so check again nearer the time.
Sunshine context Model-grid estimate, not summit sunshine
The surrounding model grid indicates 0 h of sunshine. This is not a forecast of time in sunshine on the summit. Use the cloud and views outlook above for the conditions on this mountain.
Morning · 08:00–12:00
MixedSummit winds around 10-20 mph. Gusts around 15-25 mph are possible on exposed ground.
64
Afternoon · 12:00–17:00
GoodSummit winds around 5-15 mph. Gusts around 15-25 mph are possible on exposed ground. Summit cloud is more persistent early in this period, with better prospects later.
70
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 -2°C.39Poor · 600 mView detailsHide details
Night beginning Wednesday 11 November 2026
Full overnight outlook
A poor night to camp on open ground. Light winds on open ground, gusting no more than about 20 mph. It should stay dry. A frost at every height we checked (300-900 m), down to about -2°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.
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 micaceous psammite, a hard, sandy rock flecked with mica. It grips well when dry and can be slippery when wet where the mica shows. It is generally solid and blocky. On the usual routes up you may also cross gneiss, which grips very well when dry and stays reasonably grippy when wet. 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 gust15-25 mphRain0.0 mm
Main concernmuch of the route may be in cloud
Representative rock around the summit and along available routes
Micaceous psammiteCreag Dhubh Psammite 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
Micaceous psammite is a hard, sandy rock flecked with mica. It grips well when dry and can be slippery when wet where the mica shows. 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.
Ben Alder and Beinn Bheoil
psammite, pelite or semipelite
Geological detail and BGS records
Mapped variation
3 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
Micaceous psammiteCreag Dhubh Psammite Formation535–1,130 m samplesSeen on Ben Alder and Beinn Bheoil
Micaceous psammite is a hard, sandy rock flecked with mica. It grips well when dry and can be slippery when wet where the mica shows. It is generally solid and blocky.
BGS record →
Route sample
Gneissose semipeliteCoire nan Laogh Semipelite FormationAround 798 mSeen on Ben Alder and Beinn Bheoil
Gneiss is a very old, hard, banded rock. It grips very well when dry and stays reasonably grippy when wet. It is usually very solid.
BGS record →
Route sample
Gneissose semipeliteFalls of Phones Semipelite FormationAround 960 mSeen on Ben Alder and Beinn Bheoil
Gneiss is a very old, hard, banded rock. It grips very well when dry and stays reasonably grippy when wet. It is usually very solid.
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 Ben Alder on Wednesday 11 November 2026. It asks about intentions, not whether you actually went out. No name or account is needed.
