Eryri / Snowdonia National Park
Includes all summits in the the northern half of Wales from Pumlumon northwards.
Monday's Forecast
Light wind, negligible impact
Little wind or walking hardly affected by the wind, but feeling chilly if exposed on tops. 10-15mph or less.
Dry and sunny
Extensive sunshine. The mountains free of cloud once any early mist patches disperse.
Clear
Excellent or superb visibility, no navigation issues.
Hot
Heatwave conditions. Very high temperatures, rising to 20C+ on high tops, approaching 30C in some valleys. Beware of heat stroke and dehydration. Carry plenty of liquid.
Strong warm sunshine
High UV levels, feeling very warm when ascending, beware of dehydration and sunburn.
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Light wind, negligible impact
Little wind or walking hardly affected by the wind, but feeling chilly if exposed on tops. 10-15mph or less.
Dry and sunny
Extensive sunshine. The mountains free of cloud once any early mist patches disperse.
Clear
Excellent or superb visibility, no navigation issues.
Hot
Heatwave conditions. Very high temperatures, rising to 20C+ on high tops, approaching 30C in some valleys. Beware of heat stroke and dehydration. Carry plenty of liquid.
Strong warm sunshine
High UV levels, feeling very warm when ascending, beware of dehydration and sunburn.
Viewing Forecast For
Eryri / Snowdonia National Park
Monday 25th May 2026
Last updated
Sun 24th May 26 at
4:40PM
Summary for all mountain areas
High pressure brings another extensively sunny and unseasonably hot day for England and Wales, with valley temperatures from Peak District into Wales up to 30C in afternoon. Also very warm sunshine southern and eastern Scotland, but still blustery south-westerly with low cloud and patchy drizzly rain northwest Scotland.
Headline for Eryri / Snowdonia National Park
Sunny and becoming unseasonably hot. Beware of dehydration and sunburn.
How windy? (On the summits)
South to south-westerly 10mph.
Effect of the wind on you?
Small
How Wet?
Dry
Cloud on the hills?
Mountains clear
Any early mist will soon disperse to leave the mountains clear.
Chance of cloud free summits?
90%
Sunshine and air clarity?
Widespread and strong sunshine. Good visibility, but slight haze.
How Cold? (at 900m)
20C, very humid
Freezing Level
Well above the summits. Valley temperatures inland reaching high 20s. Cooling sea breezes for coastal hills.
Viewing Forecast For
Eryri / Snowdonia National Park
Tuesday 26th May 2026
Last updated
Sun 24th May 26 at
4:40PM
How windy? (On the summits)
Varying in direction, 5-10mph or less; perhaps locally up to 15mph some coastal hills where sea breezes develop.
Effect of the wind on you?
Mostly negligible
How Wet?
Risk isolated afternoon thunderstorm
Very likely dry, but risk of cloud bubbling up in the afternoon to give an isolated, but should they occur, slow-moving heavy shower or thunderstorm.
Cloud on the hills?
Mountains clear
Perhaps some early fragments of mist and low cloud, mainly around coastal hills in the west. Otherwise, hills clear.
Chance of cloud free summits?
Sunshine and air clarity?
Widespread sunshine, but areas of cloud will bubble up in the afternoon. Visibility mostly good or very good, but slight haze.
How Cold? (at 900m)
16 to 18C, humid. Hottest mid Wales where valley temperatures will rise to 25 to 27C.
Freezing Level
Well above the summits
Viewing Forecast For
Eryri / Snowdonia National Park
Wednesday 27th May 2026
Last updated
Sun 24th May 26 at
4:40PM
How windy? (On the summits)
Southeasterly 15 to 20mph, but perhaps 30mph at times as marked gusts develop, with highest gusts not always on tops.
Effect of the wind on you?
May well be rather blustery and increasingly gusty through the day.
How Wet?
Substantially or completely dry
Perhaps the odd burst of showery rain possible later in the day, running up the west coast.
Cloud on the hills?
Low cloud, mainly east, dispersing.
Patches of banks of low cloud, mainly east Wales, will lift and break off the hills, to leave all areas clear by midday. Western mountains clear all day.
Chance of cloud free summits?
90%, but 50% east Wales morning.
Sunshine and air clarity?
Patchwork of sunshine, extensive western mountains. Visibility good, but marked haze.
How Cold? (at 900m)
16 to 18C
Freezing Level
Well above the summits
Planning Outlook
High pressure dominates this week with early patchy low cloud, mainly coastal hills dispersing to give widespread warm or very warm sunshine, still reaching into the high 20s on Tuesday Peak District into Wales with high humidity, which may spark off the odd thunderstorm, before peak daytime temperatures come down a little, when cooler for eastern hills. Chance of well scattered shower development from midweek as a gusty south-easterly develops for western hills. Pressure lowering next weekend into next week.