Eryri / Snowdonia National Park
Includes all summits in the the northern half of Wales from Pumlumon northwards.
Wednesday's Forecast
Moderate breeze, locally gusty
A noticeable breeze, feeling cool where exposed on tops. Locally may be gusty, but unlikely to affect walking progress. 15-25mph.
Patchwork of cloud and sun
Dry most or all day. A mix of cloud and sunshine. Occasional cloud banks drifting over higher slopes, lifting above the tops.
Cool to mild
Air temperature 8 to 12C on higher terrain. Comfortable temperatures on lower terrain, but feeling chilly if exposed to wind higher up, especially if stationary. Pack extra layers.
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.
Moderate breeze, locally gusty
A noticeable breeze, feeling cool where exposed on tops. Locally may be gusty, but unlikely to affect walking progress. 15-25mph.
Patchwork of cloud and sun
Dry most or all day. A mix of cloud and sunshine. Occasional cloud banks drifting over higher slopes, lifting above the tops.
Cool to mild
Air temperature 8 to 12C on higher terrain. Comfortable temperatures on lower terrain, but feeling chilly if exposed to wind higher up, especially if stationary. Pack extra layers.
Strong warm sunshine
High UV levels, feeling very warm when ascending, beware of dehydration and sunburn.
Viewing Forecast For
Eryri / Snowdonia National Park
Wednesday 20th August 2025
Last updated
Tue 19th Aug 25 at
4:32PM
Summary for all mountain areas
High pressure to northwest, north-easterly winds; gustiest England and Wales. Cloud sheet fairly extensive from dawn, breaking up through day to sunshine, but patches persisting for the northern Highlands, into eastern Border Hills, and Pennines. Best sun in the west, aside from slow-moving cloudy zone of western Argyll.
Headline for Eryri / Snowdonia National Park
Blustery and cool. Low cloud in morning, burning off, to increasing sunshine.
How windy? (On the summits)
Northeasterly 15-25mph, occasional stronger gusts over tops and elevated passes in morning.
Effect of the wind on you?
Fairly small, though buffeting gusts will blow over high terrain at times.
How Wet?
No rain expected
Local spots of drizzle in the air at first under and in low cloud.
Cloud on the hills?
Fairly extensive start, soon burning off.
From dawn, fairly extensive cloud above 700m, some banks drifting down east slopes near Carneddau/Tryfan. Hills toward west coast may start clear. Cloud sheet will soon erode back east and burn off, leaving just patches some tops by early afternoon.
Chance of cloud free summits?
30% rising to 90%
Sunshine and air clarity?
From dawn, glimpses of sun, best in the west; becoming mostly sunny during afternoon. Very good visibility, some haze east.
How Cold? (at 900m)
8 to 10C. Slopes towards mid-Wales locally warmer, up to 12C, particularly west.
Freezing Level
Above the summits
Viewing Forecast For
Eryri / Snowdonia National Park
Thursday 21st August 2025
Last updated
Tue 19th Aug 25 at
4:32PM
How windy? (On the summits)
North-easterly 20 to 30mph in morning, occasionally higher in gusts, but hour by hour easing down to 15mph afternoon.
Effect of the wind on you?
Blustery and gusty with marked wind chill in the morning. Becoming mostly small into the afternoon.
How Wet?
No rain expected
Cloud on the hills?
Capping tops, mainly north of A5.
Within a north-easterly airflow, cloud will likely cap fairly extensively hills near and north of the A5 for several hours. Elsewhere, occasional patches Snowdon.
Chance of cloud free summits?
40% north, 70% south.
Sunshine and air clarity?
Intermittent sun near and north of A5. More frequently elsewhere. Visibility very good or excellent.
How Cold? (at 900m)
7C at dawn, lifting to 11C
Freezing Level
Above the summits
Viewing Forecast For
Eryri / Snowdonia National Park
Friday 22nd August 2025
Last updated
Tue 19th Aug 25 at
4:32PM
How windy? (On the summits)
North-westerly 5 to 15mph.
Effect of the wind on you?
Small
How Wet?
Rain unlikely
Cloud on the hills?
Patches or over the Snowdon Range and hills north of the A5 banks at varying heights. Tending to burn off and lift into the afternoon, local patches may linger.
Chance of cloud free summits?
Lifting to 70%
Sunshine and air clarity?
Patchwork of sunshine, skies may fill in with cloud for a time. Visibility very good.
How Cold? (at 900m)
10C
Freezing Level
Above the summits
Planning Outlook
High pressure dominates through this week, with initial north-easterly winds, easing out as the high builds overhead with lighter winds. With a cooler air-mass in place, widely chilly dawns, with a slight frost for some valleys and glens, especially in the Highlands. Banks of cloud coming and going on the hills, with periods of sunshine, generally best in the west. Wind and rain may edge off the Atlantic into next week, but much uncertainty in detail and timing of this change.