Eryri / Snowdonia National Park
Includes all summits in the the northern half of Wales from Pumlumon northwards.
Sunday'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.
Sunshine and showers
A good amount of dry and bright weather, but scattered bursts of rain, some may be locally heavy.
Chilly
Air temperature typically 0 to 5C on higher summits. Feeling distinctly chilly on tops when stationary or where exposed to wind. Take appropriate layers.
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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.
Sunshine and showers
A good amount of dry and bright weather, but scattered bursts of rain, some may be locally heavy.
Chilly
Air temperature typically 0 to 5C on higher summits. Feeling distinctly chilly on tops when stationary or where exposed to wind. Take appropriate layers.
Viewing Forecast For
Eryri / Snowdonia National Park
Sunday 17th May 2026
Last updated
Sat 16th May 26 at
4:04PM
Summary for all mountain areas
Scattered showers for most through morning, early low cloud (lowest west) rises to and above many summits for several hours. Showers become frequent and heavy afternoon, risk of isolated lightning and hail; showers most of the day in Scotland. Breezy in exposure, strong gusts near showers, and quite chilly.
Headline for Eryri / Snowdonia National Park
Cloud lifting to and above tops; scattered showers, frequent later
How windy? (On the summits)
Westerly 15-25mph through morning and into afternoon, some lower speeds possible. Then trending southwesterly and a quick rise in speed, sustained at least 25mph, up to 35mph with stronger gusts around showers.
Effect of the wind on you?
Fairly small, then becoming more blustery through afternoon, affecting comfortable walking in exposure, considerable buffeting from strongest gusts late in the day.
How Wet?
Some showers, frequent and heavy later
A little rain toward west coast early morning, odd showers then develop inland during morning, brief heavier bursts, chance of thunder, but tending to move away eastward during afternoon. Showers return more widely for the later afternoon, frequent and heavy.
Cloud on the hills?
Morning patches, largely clearing
Banks of cloud around higher slopes mostly in west in morning. Lifting to upper slopes, clear tops at times, but briefly lowering around showers. Later, cloud returns to high terrain more persistently as rain increases in frequency.
Chance of cloud free summits?
40% rising to 80%
Sunshine and air clarity?
A patchwork of cloud and sun well into the day, clouding over more widely in the later hours. Visibility very good, but reduced in showers.
How Cold? (at 900m)
2 to 4C. Feeling nearer -5C or colder as wind increases.
Freezing Level
Above the summits.
Viewing Forecast For
Eryri / Snowdonia National Park
Monday 18th May 2026
Last updated
Sat 16th May 26 at
4:04PM
How windy? (On the summits)
South-southwesterly 15-20mph, but may be stronger up to dawn. Likely increasing afternoon to 30mph, 40mph+ overnight.
Effect of the wind on you?
Fairly small part of day, but breezy on tops, becoming increasingly blustery, affecting comfortable walking, worsening later.
How Wet?
Local showers, risk rain later in day
Patchy rain and odd showery bursts possible in morning, likely to fade or clear away eastwards middle of day. Later odd spots as high cloud thickens, into night, steadier rain develops quickly from southwest.
Cloud on the hills?
Lifting and clearing; lowering late in day
Varied cloud banks around hills in morning, particularly western areas. Lifting higher, clearing tops and increasingly breaking up into middle of day. Later as rain develops, cloud then lowering back onto hills.
Chance of cloud free summits?
40% rising to 80%; dropping by dusk.
Sunshine and air clarity?
Variable cloud, glimpses of sun, high cloud tends to build to cover the sky afternoon, overcast later. Visibility very good, reducing later in rain.
How Cold? (at 900m)
2C rising to 5C. If exposed to increasing wind later, feeling nearer -5C, or colder toward dusk.
Freezing Level
Above the summits.
Viewing Forecast For
Eryri / Snowdonia National Park
Tuesday 19th May 2026
Last updated
Sat 16th May 26 at
4:04PM
How windy? (On the summits)
Southerly 35-50mph, shifting southwesterly and easing, 25-35mph for a few hours, restrengthening to 40mph with time.
Effect of the wind on you?
Walking often at least strenuous on high summits with wind chill. Effects may ease for a few hours after morning.
How Wet?
Often raining, sometimes heavy
Persistent rain from before dawn lingers into the morning. Rain eases but remains frequent, most frequent on western slopes with heavy moments; risk of isolated hail and thunder. Wet underfoot and slippery rock surfaces.
Cloud on the hills?
Likely extensive
Extensive to low slopes at dawn. Through morning, tending to lift and break in east Wales, locally to 600-700m, any higher breaks fairly brief. Cloud remains extensive western slopes below 600m and often below 400m.
Chance of cloud free summits?
10%
Sunshine and air clarity?
Glimpses of sun in the morning, then later in the day too, otherwise largely cloudy. Visibility often poor due to rain and haze.
How Cold? (at 900m)
6 to 8C. Feeling like -5 to -8C in direct wind.
Freezing Level
Above the summits.
Planning Outlook
A mixed but milder outlook. Showery bursts of rain Monday, passing eastwards; by later Monday, strengthening southerly winds and rain moving into Wales from the southwest. Damp south-southwesterlies then prevail for a few days as mid-week approaches with regular showers, most on western hills where drizzly rain may persist between showers. Expect increasingly wet conditions underfoot, slippery rock surfaces. Also, a risk of isolated hail and lightening in the showers. Indications of high pressure building over the continent later in the week, brining milder and drier conditions to England and Wales. However, some drizzle and low cloud may continue to affect western hills, with periods of rain and wind continuing to affect Scotland. This trend may continue into the weekend, though detail currently uncertain.