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Eryri / Snowdonia National Park Forecast

Eryri / Snowdonia National Park

Includes all summits in the the northern half of Wales from Pumlumon northwards.

Friday's Forecast

Moderate breeze, locally gusty
Patchwork of cloud and sun
Clear
Cool to mild

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Click here to download the latest PDF Last Updated Thu 22nd May 25 at 4:20PM Last Updated Thu 22nd May 25 at 4:20PM
View our low-graphics version Last Updated Thu 22nd May 25 at 4:20PM Last Updated Thu 22nd May 25 at 4:20PM

Viewing Forecast For

Eryri / Snowdonia National Park
Friday 23rd May 2025
Last updated Thu 22nd May 25 at 4:20PM

Summary for all mountain areas

A sunny start for most. High cloud begins drifting over western areas, gradually thickening through afternoon. Patchy high cloud builds in eastern Scotland and down the spine of the Pennines before high cloud reaches these areas too. Overcast for most by dusk with rain setting into western coastal areas, spreading east overnight.

Headline for Eryri / Snowdonia National Park

Patchy sun, high cloud increasing; rain into night

How windy? (On the summits)

West to northwesterly 15-20mph. Gradually becoming near 20mph most areas by evening with some breezes reaching 25mph.

Effect of the wind on you?

Fairly small, some uncomfortable winds into the evening.

How Wet?

Dry most of daylight, rain setting in overnight

Dry during most or all daylight. Rain arriving from the west later afternoon, setting in most areas into the night; some heavy moments after nightfall.

Cloud on the hills?

Little cloud expected

Passing caps over highest tops in the morning lift and break for cloud-free hills.

Chance of cloud free summits?

Above 90%

Sunshine and air clarity?

Mostly sunny, fair weather cloud building. High cloud arrives from the west afternoon, becoming overcast by evening. Excellent or superb visibility.

How Cold? (at 900m)

6 or 7C, rising to 8C

Freezing Level

Above the summits

Viewing Forecast For

Eryri / Snowdonia National Park
Saturday 24th May 2025
Last updated Thu 22nd May 25 at 4:20PM

How windy? (On the summits)

West turning southwesterly, 30 to 40mph, risk strengthening further later in day, possibly 50-60mph evening into night.

Effect of the wind on you?

Considerable buffeting across higher terrain, balance challenging on exposed ridges. May deteriorate further later.

How Wet?

Drizzly rain fairly persistent

Generally feeling very damp all day in cloud, some periods of heavier drizzle, may become steadier rain occasionally; driest toward eastern areas. Risk heavier rain developing evening into the night.

Cloud on the hills?

Extensive, very low cloud west

Blanket cloud from lower slopes up most or all day toward the coasts, 400-500m fairly widely inland, some higher breaks 600-700m toward Carneddau and Berwyn.

Chance of cloud free summits?

10%

Sunshine and air clarity?

Rare if any glimpses of sun mainly further east/northeast. Generally overcast and dull, poor visibility across the mountains.

How Cold? (at 900m)

9C, little change all day. Feeling sub-zero directly in the wind.

Freezing Level

Above the summits

Viewing Forecast For

Eryri / Snowdonia National Park
Sunday 25th May 2025
Last updated Thu 22nd May 25 at 4:20PM

How windy? (On the summits)

Westerly 40-50mph. Squally gusts near showers.

Effect of the wind on you?

Walking arduous, squally gusts may inhibit forward progress or blow you over. Significant wind chill.

How Wet?

Afternoon showers, most frequent west

Rain most areas at dawn fades to occasional light showers in the west. Showers increase afternoon, most frequent in the west with some heavy bursts.

Cloud on the hills?

Intermittently shrouding tops, lower in rain

Upland terrain shrouded at dawn, bases down to 600-700m in the west. Cloud rapidly breaks and bases lift, high tops intermittently or frequently clear for a time morning. Summits then intermittently covered, bases lowering further in showers.

Chance of cloud free summits?

50%

Sunshine and air clarity?

A patchwork of sunshine, chance more frequent sun in the morning. Very good visibility, intermittently poor in rain/cloud.

How Cold? (at 900m)

4C at dawn, rising to 5 or 6C, warmest east of high tops. Feeling like -10C in direct wind.

Freezing Level

Above the summits

Planning Outlook

Low pressure facilitates a strong westerly Atlantic breeze over the weekend: blustery winds, low cloud, damp conditions for Saturday, then widely heavier rain is expected by Saturday night, accompanied by winds strengthening to gale force over many hills. Remaining very windy through Sunday and Monday with mountain gales; cooler too, with heavy showers, particularly frequent in western Scotland, a risk of hail and thunder. A changeable week follows, winds generally easing and likely a period of rain for England and Wales Tuesday. Eastern Scotland may be substantially dry with regular sun. Some improvement likely late week into the weekend.