Eryri / Snowdonia National Park
Includes all summits in the the northern half of Wales from Pumlumon northwards.
Thursday's Forecast
Gale force, walking arduous
Considerable buffeting, walking into the wind will be strenuous on exposed terrain, stronger gusts may knock you off your feet. 40 to 55mph.
Patchy rain or drizzle
Rain on and off, or generally drizzly - total amounts small, but may be persistently damp, especially where hills are shrouded in cloud.
Cool to mild
Air temperature 5 to 10C on higher terrain. Comfortable temperatures on lower terrain, but feeling chilly if exposed to wind higher up, especially if stationary. Pack extra layers.
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Gale force, walking arduous
Considerable buffeting, walking into the wind will be strenuous on exposed terrain, stronger gusts may knock you off your feet. 40 to 55mph.
Patchy rain or drizzle
Rain on and off, or generally drizzly - total amounts small, but may be persistently damp, especially where hills are shrouded in cloud.
Cool to mild
Air temperature 5 to 10C on higher terrain. Comfortable temperatures on lower terrain, but feeling chilly if exposed to wind higher up, especially if stationary. Pack extra layers.
Viewing Forecast For
Eryri / Snowdonia National Park
Thursday 10th September 2026
Last updated
Wed 9th Sep 26 at
4:10PM
Summary for all mountain areas
Windy, gales over Scottish mountains and increasingly on higher tops of England & Wales. Rain starts patchy and light but becomes persistent over western hills, extending eastwards with time. Cloud capping most high tops, lowering in rain particularly in the west.
Headline for Eryri / Snowdonia National Park
Wind strengthens to gales on tops. Rain develops.
How windy? (On the summits)
Southwesterly soon widely 30mph higher mountains, rising into middle of day to 40-45mph, stronger gusts 50mph around tops during afternoon. Moderating from dusk onward to 25mph.
Effect of the wind on you?
Walking becomes strenuous, increasingly arduous in exposure on higher terrain, strongest gusts requiring effort to maintain stability; notable wind chill.
How Wet?
Local drizzle, rain more widely and heavier afternoon
A few spots of drizzly rain drift onto hills in west Snowdonia NP/Llyn Peninsula from time to time in morning, dry windows too. With time, rain becomes more frequent, setting in for several hours over western hills, some heavier falls afternoon. Smaller amounts extend eastward. Breaking up into lighter showers from dusk.
Cloud on the hills?
Mostly western hills, more extensive later
Hills from Snowdon group west to Llyn Peninsula often shrouded above 700m. Some early cloud towards Carneddau and east Wales will break up, and more widely broken for a few hours. From mid-afternoon, cloud increasingly fills in, lowering in rain, to mid-slopes near Cardigan Bay later.
Chance of cloud free summits?
40%, lowering to 10% afternoon
Sunshine and air clarity?
Glimpses of sun mainly north and east, high cloud builds, then mostly cloudy. Good visibility, a haze towards the Irish Sea.
How Cold? (at 900m)
7C rising to 9C, slightly higher later in day, then lowering slightly into night. Feeling near or just below freezing in strongest wind.
Freezing Level
Above the summits.
Viewing Forecast For
Eryri / Snowdonia National Park
Friday 11th September 2026
Last updated
Wed 9th Sep 26 at
4:10PM
How windy? (On the summits)
Northwesterly 20-25mph to start, easing, to 10-15mph afternoon. Starting to increase again into night.
Effect of the wind on you?
Blustery and cool in exposure early in day, becoming mostly small.
How Wet?
Soon dry
A little drizzle over the high tops in cloud in the early morning, soon fading for dry hills.
Cloud on the hills?
Fairly extensive early, improving
Most high terrain starts in cloud, bases towards middle slopes from Llyn Peninsula to Carneddau. Cloud will lift with time, breaks forming, soonest Berwyn group and increasingly widely. High Snowdon group summits will be slow to clear.
Chance of cloud free summits?
Rising to 50%
Sunshine and air clarity?
Sunshine increasingly breaks out. Good visibility, though a haze building.
How Cold? (at 900m)
8 or 9C, later trending slightly cooler. Feeling near freezing at first on tops in wind.
Freezing Level
Above the summits.
Viewing Forecast For
Eryri / Snowdonia National Park
Saturday 12th September 2026
Last updated
Wed 9th Sep 26 at
4:10PM
How windy? (On the summits)
Southwesterly, rising through dawn to 40-50mph, may reach 60mph higher northern tops during the day.
Effect of the wind on you?
Challenging conditions with increasingly powerful gusts to some low levels; walking becoming difficult on exposed tops.
How Wet?
Heavy rain develops, sets in
Rain initially patchy, but likely becomes more persistent northwestern Eryri, then more widely, heavier falls developing, risk setting in continuously with time, lasting onward into evening.
Cloud on the hills?
Increasingly extensive
Banks of low cloud over hills toward the west in the morning, some early breaks more north and eastern groups. Filling in and lowering widely in rain.
Chance of cloud free summits?
20%
Sunshine and air clarity?
Overcast, increasingly dull. Hazy, then widely poor visibility in rain
How Cold? (at 900m)
9C rising to 12C. Feeling like -5C directly in wind.
Freezing Level
Above the summits.
Planning Outlook
Changeable west-southwesterlies prevail through mid September; often windy, gale-force winds for periods over higher terrain. A window of drier weather this Friday, then the next frontal system sweeps in overnight into Saturday with a sustained fall of rain moving southeastward, accompanied by upland gales for most places. Improving for better weather on Sunday, then wind and rain returns into Monday, staying showery into Tuesday. A mixed outlook likely continues later next week with rain most frequent in western Scotland. Temperatures varying, some cooler days especially in Scotland, but often fairly mild further south, at times quite warm and humid.