Eryri / Snowdonia National Park
Includes all summits in the the northern half of Wales from Pumlumon northwards.
Sunday's Forecast
Windy, walking impeded
Blustery conditions enough to give buffeting on higher terrain or affect balance on exposed ridges. 25 to 40mph.
Thunderstorms
Bursts of rain, torrential downpours with hail, risk of thunder and lightning. Seek shelter where possible.
Poor visibility
Murky conditions with areas of fog shrouding the hills, making navigation challenging. Map and compass essential.
Warm
Comfortable temperatures on the hills, 10 to 15C on tops, feeling pleasantly warm especially on lower ground. Beware of feeling cooler if exposed to wind on higher terrain.
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Windy, walking impeded
Blustery conditions enough to give buffeting on higher terrain or affect balance on exposed ridges. 25 to 40mph.
Thunderstorms
Bursts of rain, torrential downpours with hail, risk of thunder and lightning. Seek shelter where possible.
Poor visibility
Murky conditions with areas of fog shrouding the hills, making navigation challenging. Map and compass essential.
Warm
Comfortable temperatures on the hills, 10 to 15C on tops, feeling pleasantly warm especially on lower ground. Beware of feeling cooler if exposed to wind on higher terrain.
Viewing Forecast For
Eryri / Snowdonia National Park
Sunday 30th August 2026
Last updated
Sat 29th Aug 26 at
4:30PM
Summary for all mountain areas
Areas of rain and low cloud around many mountains. Some drier periods in the morning, but into afternoon increasingly widespread heavy downpours and thunderstorms develop. Fairly light winds for much of the Highlands, becoming breezier England, stronger winds on Welsh mountains.
Headline for Eryri / Snowdonia National Park
Rain and increasingly thundery bursts. Wind strengthening.
How windy? (On the summits)
South-southwesterly 20-25mph in morning, strengthening, to often 35mph afternoon with some stronger gusts around showers.
Effect of the wind on you?
Increasingly blustery, ease of walking becomes affected, then more strenuous conditions, gusts knocking you off balance on exposed high areas; marked wind chill.
How Wet?
Rain most of day, heavy downpours; risk of lightning
Rain and drizzle in the morning, fairly persistent on western hills, some heavier falls; drier for a time in east. Developing increasingly by late morning onward into widely frequent heavy bursts of rain, risk of hail and thunder.
Cloud on the hills?
Fairly extensive, brief improvement
Fairly extensive from dawn, many hills shrouded to middle slopes, particularly west. A lifting trend for a time, some high breaks forming to north & east. Cloud will fill back in across high terrain and increasingly lower as rain sets in.
Chance of cloud free summits?
20%
Sunshine and air clarity?
Largely cloudy, rare brief sun. Visibility varying, poor in rain, locally good if dry, mainly east in morning.
How Cold? (at 900m)
10C rising to 12C, cooling again before evening. Feeling like 0 to 3C in strongest wind.
Freezing Level
Above the summits.
Viewing Forecast For
Eryri / Snowdonia National Park
Monday 31st August 2026
Last updated
Sat 29th Aug 26 at
4:30PM
How windy? (On the summits)
Westerly 25 to 40mph, strongest morning up to middle of day, then tending to lessen gradually afternoon into evening.
Effect of the wind on you?
Blustery, making walking uncomfortable on exposed high terrain, in places frequent buffeting. Marked wind chill.
How Wet?
Rain on and off, fading afternoon
Showery rain frequent for several hours, some heavier moments mixed in, then tending to improve from the west to fewer showers during the afternoon. Patchy rain returns from west into night.
Cloud on the hills?
Lowest morning, rising higher, breaks
Fairly extensive across the hills in the morning, to lower elevations for a time near west coast. The base rising toward upper slopes, increasing high breaks afternoon.
Chance of cloud free summits?
20% rising to 70%
Sunshine and air clarity?
Largely cloudy, rare glimpses of sun, then sun developing near coast and extending inland; high cloud later builds. Visibility becomes good, some haze west.
How Cold? (at 900m)
7 to 9C. Feeling near or just below freezing directly in the wind.
Freezing Level
Above the summits.
Viewing Forecast For
Eryri / Snowdonia National Park
Tuesday 1st September 2026
Last updated
Sat 29th Aug 26 at
4:30PM
How windy? (On the summits)
West to southwesterly 25 to 30mph.
Effect of the wind on you?
Blustery, affecting ease of walking and balance on exposed tops and ridges. Marked wind chill.
How Wet?
Generally damp in west
A mix of drizzle and some steady rain much of the day over western hills. Smaller amounts further east.
Cloud on the hills?
Fairly extensive, lowest west
Banks of cloud often cap higher slopes above 600 to 800m, lowest near Cardigan Bay. Some breaks at times, best further east where only patchy on tops.
Chance of cloud free summits?
30%
Sunshine and air clarity?
Generally cloudy, glimpses of sun toward north and east. Visibility reduced in rain, better if drier, more often east.
How Cold? (at 900m)
9 or 10C, little change all day. Feeling around 0C in the wind on tops.
Freezing Level
Above the summits.
Planning Outlook
A generally unsettled outlook during the first two weeks of September with frequent rain and strong winds. Low pressure dominates and a series of frontal systems move in from the Atlantic. West to southwesterlies, often gale force over the mountains in the second half of this week. Heavy rain most prolonged in the west where increasingly wet underfoot, streams rising to be in spate. Low cloud often covering the hills. Temperatures varying, some notably cooler days for Scotland, at times more humid air mainly toward the south.