Eryri / Snowdonia National Park
Includes all summits in the the northern half of Wales from Pumlumon northwards.
Tuesday'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.
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.
Click an icon for more information or click here for a key to all icons.
Light wind, negligible impact
Little wind or walking hardly affected by the wind, but feeling chilly if exposed on tops. 10-15mph or less.
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
Tuesday 23rd June 2026
Last updated
Mon 22nd Jun 26 at
1:56PM
Summary for all mountain areas
Becoming very warm and humid, particularly Wales where exceptionally so. Chillier north and west of Scotland, especially near the coast where it will become drizzly and misty. Elsewhere, be aware of dehydration and sunburn..
Headline for Eryri / Snowdonia National Park
Very warm indeed. Extensive sunshine.
How windy? (On the summits)
Southwesterly 15mph; dropping to less than 10mph and direction becoming variable.
Effect of the wind on you?
Negligible
How Wet?
Rain very unlikely
Cloud on the hills?
Not expected
Chance of cloud free summits?
Almost certain
Sunshine and air clarity?
Sunshine extensive, sometimes weak due to thin high level cloud. Good visibility although hazy.
How Cold? (at 900m)
18C rising to a very warm (and exceptionally humid) 21 to on eastern summits 23C.
Freezing Level
Above the summits.
Viewing Forecast For
Eryri / Snowdonia National Park
Wednesday 24th June 2026
Last updated
Mon 22nd Jun 26 at
1:56PM
How windy? (On the summits)
Direction may well vary, 10mph or less.
Effect of the wind on you?
Negligible
How Wet?
Rain not expected
Cloud on the hills?
Little if any
Risk fog lowest coastal slopes/cliffs at times. The hills fog free.
Chance of cloud free summits?
90%
Sunshine and air clarity?
Extensive sunshine. Persistent haze.
How Cold? (at 900m)
21C rising toward an exceptionally hot 22 to perhaps 26C.
Freezing Level
Above the summits.
Viewing Forecast For
Eryri / Snowdonia National Park
Thursday 25th June 2026
Last updated
Mon 22nd Jun 26 at
1:56PM
How windy? (On the summits)
South to southeasterly between 10 and 20mph; perhaps particularly gusty at times.
Effect of the wind on you?
Generally small, although there may be sudden buffeting at times both on higher areas and some lower slopes.
How Wet?
Small risk thunderstorms
Risk thunderstorms developing later afternoon giving locally torrential rain.
Cloud on the hills?
Little if any although patches may form near rain
Mountains extensively cloud free. In thunderstorms, fog may be extensive some hills, in places from lower slopes up.
Chance of cloud free summits?
90%
Sunshine and air clarity?
Periods of sunshine. Persistent haze.
How Cold? (at 900m)
Exceptionally warm 25 to 28C in afternoon. Unusally humid.
Freezing Level
Above the summits.
Planning Outlook
Exceptionally warm and humid most mountain areas until later Friday. The range in temperature in the detailed forecasts for Wednesday and Thursday reflect uncertainty in just how far north the extreme heat will penetrate - with more recent forecasts suggesting the (even) more extreme temperatures. Scattered thunderstorms on Thursday and Friday, whilst over the weekend, progressively less warm as fronts begin to come in off the Atlantic, bringing bands of rain and low cloud, particularly affecting western mountains.