Eryri (Snowdonia) mountain weather forecast.

Sat 21 Nov on the hillsA poor day on the tops in Eryri (Snowdonia), with very strong, gusty winds and burns likely to be in spate. See wind, cloud base and timings

Winter conditions outlook

Snow on the hills from tomorrow

Eryri (Snowdonia): the 2 outlook areas covering its hills. All winter outlooks

Cadair IdrisSignificant from tomorrowTomorrow: Fresh snow and drifting tomorrow, deepest on north-west through north to north-east-facing slopes.

TodayLittle or no lying snow expected on the hills.

Little or no snow lying yet. More snow to come: 10 to 20 cm tomorrow.

Read the full outlook Snow on the hills, Frozen turf, Snow to come

Snow on the hills

Expect little or no lying snow. Old patches may survive in sheltered gullies.

Frozen turf

Turf is not expected to be frozen, so frozen-turf scrambles and winter routes will not be in condition.

Snow to come

Tomorrow: 10 to 20 cm of snow expected on the tops, drifting onto north-west through north to north-east-facing slopes. On Tuesday: 20 to 30 cm of snow expected on the tops, drifting onto north-west through north to north-east-facing slopes.

TomorrowFresh snow and drifting tomorrow, deepest on north-west through north to north-east-facing slopes.

Snow lying above about 400 m. 10 to 20 cm of new snow tomorrow. Loose, soft snow underfoot. More snow to come: 20 to 30 cm on Tuesday.

Read the full outlook Snow on the hills, Fresh snow, Where the wind will put the snow, Cornices, Underfoot, Frozen turf, Snow to come

Snow on the hills

Expect snow lying above about 400 m. Drifts will be deepest on north-west through north to north-east-facing slopes, where soft snow may be knee-deep or more in hollows and gully tops.

Fresh snow

10 to 20 cm of new snow is forecast at around 750 m tomorrow. Expect it to be soft and deep in places, and slow going. New snow takes a day or two to settle. Rain or a thaw will make the snow wet and heavy, especially in the afternoon. A hard frost afterwards would freeze the surface solid again.

Where the wind will put the snow

Expect gale-force southerly winds, around 77 mph on the tops, to blow the snow about. It will pile into drifts on north-west through north to north-east-facing ground, especially below ridges, crags and corrie rims, and in gullies and hollows. Slopes facing into the wind will be scoured, with thinner snow and more rock and ice showing.

Cornices

Cornices are likely to grow above north-facing slopes because there will be plenty of new snow to move; a 77 mph wind is strong enough to carry loose snow; and that wind will blow across the ridges from the south. A cornice is an overhanging lip of snow built out over the drop by the wind. It can break well back from the edge, so keep well away from it, especially in poor visibility, and do not linger below one, particularly as it warms.

Underfoot

Expect new, loose snow on top, with hard going in deeper drifts. Conditions will change through the day: thawing intermittently for 13 hours between 00:00 and 18:00.

Frozen turf

Turf is not expected to be frozen, so frozen-turf scrambles and winter routes will not be in condition.

Snow to come

On Tuesday: 20 to 30 cm of snow expected on the tops, drifting onto north-west through north to north-east-facing slopes.

Avalanches

As a general rule, most avalanches happen during heavy snowfall or in the day or two after it, while the new snow is still settling. Wind-drifted snow on steep slopes is the most common cause of avalanches in British hills, and it can stay unstable for a day or two after the wind drops. Rain or a sharp thaw on lying snow makes wet snow slides more likely on steep slopes. See the note below for where to find an avalanche forecast.

Tue 17 NovFresh snow and drifting on Tuesday, deepest on north-west through north to north-east-facing slopes.

Snow lying on the tops. 10 to 20 cm of new snow on Tuesday. Wet, heavy snow underfoot.

Read the full outlook Snow on the hills, Fresh snow, Where the wind will put the snow, Cornices, Underfoot, Frozen turf

Snow on the hills

Expect snow lying on the tops. Drifts will be deepest on north-west and north-facing slopes, where soft snow may be knee-deep or more in hollows and gully tops.

Fresh snow

10 to 20 cm of new snow is forecast at around 750 m on Tuesday. Expect it to be soft and deep in places, and slow going. New snow takes a day or two to settle. Rain or a thaw will make the snow wet and heavy, especially in the afternoon. A hard frost afterwards would freeze the surface solid again.

Where the wind will put the snow

Expect gale-force southerly winds, around 44 mph on the tops, to blow the snow about. It will pile into drifts on north-west through north to north-east-facing ground, especially below ridges, crags and corrie rims, and in gullies and hollows. Slopes facing into the wind will be scoured, with thinner snow and more rock and ice showing.

Cornices

Cornices are likely to grow above north-west and north-facing slopes because there will be plenty of new snow to move; a 44 mph wind is strong enough to carry loose snow; and that wind will blow across the ridges from the south. A cornice is an overhanging lip of snow built out over the drop by the wind. It can break well back from the edge, so keep well away from it, especially in poor visibility, and do not linger below one, particularly as it warms.

Underfoot

Expect wet, heavy snow. It balls up under crampons and can slide on steep ground. Conditions will change through the day: thawing from 09:00 onward after a frozen night.

Frozen turf

Turf is not expected to be frozen, so frozen-turf scrambles and winter routes will not be in condition.

Avalanches

Wed 18 NovSome new snow expected on top of the existing cover.

Snow lying on the tops. 10 to 20 cm of new snow over the three days to Wednesday. Wet, heavy snow underfoot.

Read the full outlook Snow on the hills, Fresh snow, Cornices, Underfoot, Frozen turf

Snow on the hills

Expect snow lying on the tops.

Fresh snow

10 to 20 cm of new snow is forecast over the three days to Wednesday. Rain or a thaw will make the snow wet and heavy, especially in the afternoon. A hard frost afterwards would freeze the surface solid again.

Cornices

Cornices are likely to grow above north-west and north-facing slopes because there will be plenty of new snow to move. A cornice is an overhanging lip of snow built out over the drop by the wind. It can break well back from the edge, so keep well away from it, especially in poor visibility, and do not linger below one, particularly as it warms.

Underfoot

Expect wet, heavy snow. It balls up under crampons and can slide on steep ground. Conditions will change through the day: thawing right through, day and night.

Frozen turf

Turf is not expected to be frozen, so frozen-turf scrambles and winter routes will not be in condition.

Avalanches

Rain or a sharp thaw on lying snow makes wet snow slides more likely on steep slopes. See the note below for where to find an avalanche forecast.

Thu 19 NovSome new snow expected on top of the existing cover.

Snow lying on the tops. 10 to 20 cm of new snow over the three days to Thursday. Wet, heavy snow underfoot.

Read the full outlook Snow on the hills, Fresh snow, Underfoot, Frozen turf

Snow on the hills

Expect snow lying on the tops.

Fresh snow

10 to 20 cm of new snow is forecast over the three days to Thursday. Rain or a thaw will make the snow wet and heavy, especially in the afternoon. A hard frost afterwards would freeze the surface solid again.

Underfoot

Expect wet, heavy snow. It balls up under crampons and can slide on steep ground. Conditions will change through the day: thawing right through, day and night.

Frozen turf

Turf is not expected to be frozen, so frozen-turf scrambles and winter routes will not be in condition.

Avalanches

Rain or a sharp thaw on lying snow makes wet snow slides more likely on steep slopes. See the note below for where to find an avalanche forecast.

Fri 20 NovFirm, frozen snow expected: good for crampons, but a slip can be hard to stop.

Snow lying on the tops. Firm, frozen snow underfoot: crampons and an ice axe matter.

Read the full outlook Snow on the hills, Fresh snow, Underfoot, Frozen turf

Snow on the hills

Expect snow lying on the tops.

Fresh snow

Rain or a thaw will make the snow wet and heavy, especially in the afternoon. A hard frost afterwards would freeze the surface solid again.

Underfoot

Expect firm névé: old snow that has thawed and refrozen. Crampons grip it well, but a slip on it can be very hard to stop, so an ice axe matters. Conditions will change through the day: thawing 11:00-17:00 after a frozen night, refreezing by evening.

Frozen turf

Turf is not expected to be frozen, so frozen-turf scrambles and winter routes will not be in condition.

Avalanches

Rain or a sharp thaw on lying snow makes wet snow slides more likely on steep slopes. See the note below for where to find an avalanche forecast.

Eryri (Snowdonia)Thin coverToday: Little or no lying snow expected on the hills.

TodayLittle or no lying snow expected on the hills.

Little or no snow lying yet. More snow to come: a few centimetres tomorrow.

Read the full outlook Snow on the hills, Frozen turf, Snow to come

Snow on the hills

Expect little or no lying snow. Old patches may survive in sheltered gullies.

Frozen turf

Turf is not expected to be frozen, so frozen-turf scrambles and winter routes will not be in condition.

Snow to come

Tomorrow: a few centimetres of snow expected on the tops, drifting onto north-facing slopes. On Tuesday: 20 to 30 cm of snow expected on the tops, drifting onto north-west through north to north-east-facing slopes.

TomorrowLittle or no lying snow expected on the hills.

Little or no snow lying yet. A few centimetres of new snow tomorrow. More snow to come: 20 to 30 cm on Tuesday.

Read the full outlook Snow on the hills, Fresh snow, Where the wind will put the snow, Frozen turf, Snow to come

Snow on the hills

Expect little or no lying snow. Old patches may survive in sheltered gullies.

Fresh snow

A few centimetres of new snow is forecast tomorrow. It will be deeper where the wind piles it into drifts.

Where the wind will put the snow

Expect gale-force southerly winds, around 50 mph on the tops, to blow the snow about. It will pile into drifts on north-facing ground, especially below ridges, crags and corrie rims, and in gullies and hollows. Slopes facing into the wind will be scoured, with thinner snow and more rock and ice showing.

Frozen turf

Turf is not expected to be frozen, so frozen-turf scrambles and winter routes will not be in condition.

Snow to come

On Tuesday: 20 to 30 cm of snow expected on the tops, drifting onto north-west through north to north-east-facing slopes.

Tue 17 NovA thin, patchy covering of snow expected on the tops.

5 to 10 cm of new snow on Tuesday. Gale-force southerly winds will drift the snow onto north-west through north to north-east-facing slopes.

Read the full outlook Snow on the hills, Fresh snow, Where the wind will put the snow, Spindrift, Cornices, Frozen turf

Snow on the hills

Expect a thin, patchy covering on the tops, with small drifts in sheltered spots. Snow over grass and rock is slippery, and frozen patches can be icy.

Fresh snow

5 to 10 cm of new snow is forecast on Tuesday. It will be deeper where the wind piles it into drifts. Rain or a thaw will make the snow wet and heavy, especially in the afternoon. A hard frost afterwards would freeze the surface solid again.

Where the wind will put the snow

Expect gale-force southerly winds, around 47 mph on the tops, to blow the snow about. It will pile into drifts on north-west through north to north-east-facing ground, especially below ridges, crags and corrie rims, and in gullies and hollows. Slopes facing into the wind will be scoured, with thinner snow and more rock and ice showing.

Spindrift

Spindrift is likely from the morning into the afternoon: loose snow lifted by the wind and blown towards the north. Heading southwards, into it, will be hard work, and visibility can drop sharply in gusts. Goggles make a big difference, keeping the snow out of your eyes so you can still see where you are going. Expect it to stream over crag tops and down north-west through north to north-east-facing gullies.

Cornices

Small cornices may start to form above north-west through north to north-east-facing edges where the wind piles up loose snow. Even a small one can give way, so keep back from the edge.

Frozen turf

Turf is not expected to be frozen, so frozen-turf scrambles and winter routes will not be in condition.

Avalanches

Rain or a sharp thaw on lying snow makes wet snow slides more likely on steep slopes. See the note below for where to find an avalanche forecast.

Wed 18 NovA thin, patchy covering of snow expected on the tops.

5 to 10 cm of new snow over the three days to Wednesday.

Read the full outlook Snow on the hills, Fresh snow, Cornices, Frozen turf

Snow on the hills

Expect a thin, patchy covering on the tops, with small drifts in sheltered spots. Snow over grass and rock is slippery, and frozen patches can be icy.

Fresh snow

5 to 10 cm of new snow is forecast over the three days to Wednesday. Rain or a thaw will make the snow wet and heavy, especially in the afternoon. A hard frost afterwards would freeze the surface solid again.

Cornices

Small cornices may start to form above north-facing edges where the wind piles up loose snow. Even a small one can give way, so keep back from the edge.

Frozen turf

Turf is not expected to be frozen, so frozen-turf scrambles and winter routes will not be in condition.

Avalanches

Rain or a sharp thaw on lying snow makes wet snow slides more likely on steep slopes. See the note below for where to find an avalanche forecast.

Thu 19 NovA thin, patchy covering of snow expected on the tops.

5 to 10 cm of new snow over the three days to Thursday.

Read the full outlook Snow on the hills, Fresh snow, Frozen turf

Snow on the hills

Expect a thin, patchy covering on the tops, with small drifts in sheltered spots. Snow over grass and rock is slippery, and frozen patches can be icy.

Fresh snow

5 to 10 cm of new snow is forecast over the three days to Thursday. Rain or a thaw will make the snow wet and heavy, especially in the afternoon. A hard frost afterwards would freeze the surface solid again.

Frozen turf

Turf is not expected to be frozen, so frozen-turf scrambles and winter routes will not be in condition.

Avalanches

Rain or a sharp thaw on lying snow makes wet snow slides more likely on steep slopes. See the note below for where to find an avalanche forecast.

Fri 20 NovA thin, patchy covering of snow expected on the tops.

Read the full outlook Snow on the hills, Fresh snow, Frozen turf

Snow on the hills

Expect a thin, patchy covering on the tops, with small drifts in sheltered spots. Snow over grass and rock is slippery, and frozen patches can be icy.

Fresh snow

No significant new snow is expected, and none will have fallen for about 3 days, so the snow will have had time to settle. Rain or a thaw will make the snow wet and heavy, especially in the afternoon. A hard frost afterwards would freeze the surface solid again.

Frozen turf

Turf is not expected to be frozen, so frozen-turf scrambles and winter routes will not be in condition.

Avalanches

Rain or a sharp thaw on lying snow makes wet snow slides more likely on steep slopes. See the note below for where to find an avalanche forecast.

Written from a computer model of the weather and snow, not from reports on the hill. Conditions on the ground can differ, so look and judge for yourself.

Winter conditions outlook: Mountain Conditions by Spatial Terrain Ltd, used with permission. Issued 15 November 2026 at 13:33 UTC.

Choose your hills and day.

Each regional brief uses a high-ground level that suits the terrain, from 500 m on Dartmoor and in the Peak District to 900 m in the highest ranges.

Mountain Weather brief

Eryri (Snowdonia)

Saturday 21 November 2026 · Yr Wyddfa, the Glyderau and the Carneddau

Confidence: Unavailable Why?

A comparable model-confidence estimate is not available for this forecast.

What matters most

A poor day on the tops in Eryri (Snowdonia), with very strong, gusty winds and burns likely to be in spate.

High-ground wind · 900 m35-45 mph southerly Gusts · 900 m50-60 mph Cloud base700-1400 m Feels like · 900 m-4 to 0°C

Regional median

Sunshine and sky

Sunshine through the day. The time blocks show where the model places the brighter spells.

Modelled sunshine3.5 h40% of daylight

Early1 h sunshine

Midday1.8 h sunshine

Later0 h sunshine

These are direct modelled sunshine hours during daylight, not the probability of sunshine. Cloud cover and summit cloud are assessed separately in the forecast above. The regional median prevents one unusually bright or dull summit cell defining the whole area.

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

Morning · 08:00–12:00PoorSummit winds around 25-45 mph. Gusts around 50-60 mph are possible on exposed ground. Gusts this strong can make walking very difficult and tiring, with a risk of being blown off your feet. Avoid exposed ridges and edges. Rain is forecast on some hills during this period. Cloud may restrict summit views early on.

Afternoon · 12:00–17:00Severe hill conditionsMore rain is expected. Summit winds around 30-45 mph. Gusts around 55-65 mph are possible on exposed ground. Gusts this strong can make walking very difficult and tiring, with a risk of being blown off your feet. Avoid exposed ridges and edges. Rain is forecast on some hills during this period. Cloud may restrict summit views around midday and later. Rain is forecast in parts of the area during the afternoon, but its extent and local amounts are uncertain.

-8

Conservative regional grades across representative summits, so one sheltered hill does not overstate the wider area.

High-ground wind (900 m)

At around 900 m, expect a southerly wind of 35–45 mph, gusting 50–60 mph. Gusts like that are strong enough to make walking very difficult and tiring, with a risk of being blown off your feet. Avoid exposed ridges and edges.

Walking impact

Gusts of 50–60 mph are strong enough to make walking very difficult and tiring, with a risk of being blown off your feet. Avoid exposed ridges and edges.

Spate risk

High spate risk based on forecast rainfall. Burns and unbridged crossings may become difficult or impassable. Timing and severity can vary between catchments. Check the peak forecast for the separate rain/runoff periods. Turn back if a crossing looks unsafe.

Rain and showers

A band of rain moves in around midday, heavy at times. Expect 10–20 mm in total. Rain is forecast in parts of the area during the afternoon, but its extent and local amounts are uncertain. Drizzle is possible on some hills.

Cloud-free summits

Clear-summit estimate: about 30% early, about 25% around midday and about 20% later.

Cloud and visibility

The tops are likely to drift in and out of cloud, with the best chance of clear tops early on. The cloud base lowers through the day. 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. Any sunshine is more likely on lower ground than on the summits.

Temperature and wind chill

At around 900 m it will be 4 to 8°C, feeling like -4 to 0°C in the wind. Take a hat, gloves, a windproof and a spare warm layer. Pack waterproofs too, and keep a warm layer dry in your pack.

Freezing level

The freezing level is above the summits.

Daylight

Sunrise 07:50, Sunset 16:12, about 8.4 hours daylight.

Overnight · 17:00–08:00Wild campingBetaToo windy for an exposed pitch above about 600 m on some hills (gusts of about 45 mph and about 8 mm of rain). Lower down, a poor night to camp on open ground. 19Poor · 600 m View detailsHide details

Regional night beginning Saturday 21 November 2026

Full regional overnight outlook

Too windy for an exposed pitch above about 600 m on some hills. Lower down, a poor night to camp on open ground. Gusts reach about 45 mph around 900 m and nearer 35 mph around 300 m, enough to damage a tent on open ground. Check the forecast for the hill and height you have in mind, and don't assume lower ground will be sheltered. About 8 mm of rain is forecast overnight. 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. Overnight lows of about 4°C at 900 m.

Overnight rain7.6 mmOpen ground · 600 m26 mph · gusts 40 mphMorning pack-upDampness possible

Moon overnight

Waxing gibbous moon

Illuminated disc: 91%
Moonrise: Outside this window
Moonset: 05:04 next morning GMT

Cloud and terrain vary across the area. Illumination describes the sunlit part of the Moon, not brightness at your pitch.

Overnight window: 21 Nov, 17:00 GMT to 22 Nov, 08:00 GMT. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.

Representative location: 53.069, -4.076. Times vary across the area.

Elevation reference (open ground)

300 m39 · poor

Wind / gust: 22 mph / 33 mph
Coldest: 6.1°C
In cloud: 0% of modelled night
Condensation: High

600 m19 · very poor

Wind / gust: 26 mph / 40 mph
Coldest: 6.1°C
In cloud: 40% of modelled night
Condensation: High

900 m9 · very poor

Wind / gust: 31 mph / 47 mph
Coldest: 4.1°C
In cloud: 53% of modelled night
Condensation: High

Open-hillside guidance across representative hills. Local shelter, ridges, tent design and the exact pitch can change conditions substantially. Read about sleeping-bag comfort ratings, pitching in strong winds or using the wild-camping forecast.

Daytime · exposed rockClimbing & scramblingBetaSnow is likely to be lying on some high ground. Scrambling may require winter mountaineering skills and equipment. Wet rock is likely. Gusts near 55 mph may affect balance on exposed rock. 0Poor · Very poor View detailsHide details

Regional rock conditions · sampled mountain terrain

Regional climbing & scrambling outlook

A broad guide to dampness and exposed rock across the area, not a forecast for every crag. Lower, sheltered crags and individual rock types may behave differently.

Conditions for exposed scrambling across the area look very poor (0/100). Rain is likely to leave rock wet. Polished slabs, vegetation and drainage lines may be notably worse. Gusts may reach about 55 mph on exposed ground, making crosswinds an important route consideration. Mapped summit-point geology across the representative hills includes volcanic rock and slate or mudstone. Rock can therefore respond differently to moisture between crags and routes.

Rock surfaceWet rock likelyExposed gust55 mphRain21.0 mm

Mapped rock across sampled summits2 broad familiesSummit samples, not a survey of every crag

volcanic rock 88% 7 representative summitsOften grippy when dry, but volcanic rocks vary widely; wet lichen, smooth holds and local seepage can still make them slippery.slate or mudstone 12% 1 representative summitOften positive when dry, but smooth, polished or slabby sections can become markedly more slippery when damp.

Representative summit-point samples across the region; individual crags and routes may differ.

Generic exposed hands-on-rock terrain across representative summits; mapped summit-point geology is a broad regional sample, not a named-route survey. Contains British Geological Survey materials © UKRI 2026. How to use the climbing and scrambling forecast.

Recommended kit for this dayWeather-aware packing prompts, plus your core hillwalking kitView kit

For a day hillwalk, not a complete route-specific checklist. Carry navigation and backup you can use, warm and waterproof layers, suitable footwear, food and water, a headtorch, emergency shelter, first aid and a way to call for help. Snow, ice, technical terrain and overnight trips need additional equipment and skills.

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

Updated 15 November 2026 at 16:26 UTC. See typical weekly and monthly conditions for Eryri (Snowdonia).

More context for your hill day

Check the approach as well as the tops

Compare midge conditions by day and height, or look for a possible cloud inversion. For Snowdon and Tryfan, camera-derived cloud-base observations add a view of conditions already seen on the slopes.

Eryri (Snowdonia) midge forecast Cloud inversion forecast Snowdon and Tryfan cloud observations

Forecasts built around recognisable hill country.

Twenty distinct regions replace inherited service boundaries. Each uses a representative height suited to its terrain; named summits retain their exact height and exposure.