Mountain Weather
Information Service
Eryri / Snowdonia National Park Forecast

Eryri / Snowdonia National Park

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

Today's Forecast

Moderate breeze, locally gusty
Sunshine and showers
Warm

Click an icon for more information or click here for a key to all icons.

Click here to download the latest PDF Last Updated Fri 18th Jul 25 at 4:17PM Last Updated Fri 18th Jul 25 at 4:17PM
View our low-graphics version Last Updated Fri 18th Jul 25 at 4:17PM Last Updated Fri 18th Jul 25 at 4:17PM

Viewing Forecast For

Eryri / Snowdonia National Park
Saturday 19th July 2025
Last updated Fri 18th Jul 25 at 4:17PM

Summary for all mountain areas

Some early rain near west coast, but the Highlands largely dry in morning. Into afternoon, bursts of rain becoming extensive heavy rain. A swathe of prolonged heavy rain moves north over England; intense downpours and thunderstorms, focused on Pennines. A few local showers Wales, but often dry. Fairly warm, locally gusty.

Headline for Eryri / Snowdonia National Park

Varied cloud, possible showers. Mostly light wind.

How windy? (On the summits)

South to southeasterly, mostly 10mph or less, but toward west coast risk gusty 20mph for periods, more widely afternoon.

Effect of the wind on you?

Mostly small

How Wet?

Risk of a shower

Often dry much of the day, bar an odd patch of rain or brief heavy shower, chance of very isolated thunder afternoon-evening.

Cloud on the hills?

Lifting, clearing many tops

Patchy cloud banks on hills in the morning. Lifting into middle of day to upper slopes and breaking above tops. Some patches may come and go over upper slopes, patches lower around showers.

Chance of cloud free summits?

40% rising to 70%

Sunshine and air clarity?

High cloud often covering the sky, but some sun breaking through afternoon. Visibility increasingly very good.

How Cold? (at 900m)

13 or 14C, small variation.

Freezing Level

Above the summits

Viewing Forecast For

Eryri / Snowdonia National Park
Sunday 20th July 2025
Last updated Fri 18th Jul 25 at 4:17PM

How windy? (On the summits)

South or southeasterly, 20 to 25mph, at times 30mph and very gusty. Occasionally dropping lighter.

Effect of the wind on you?

Often blustery, affecting walking and balance in exposure for periods; occasionally fairly small.

How Wet?

Rain on and off, thundery bursts

Rain frequent throughout the day, sometimes patchy and drizzly, but some heavier bursts likely on and off, risk of thundery downpours, particularly by afternoon greater risk of thunderstorms.

Cloud on the hills?

Varied, sometimes to lower slopes

Low cloud fairly widespread early in day. May lift to higher slopes and break for a time, best in west, but often capping higher tops. Around rain, filling in extensively, ragged patches from lower slopes upward.

Chance of cloud free summits?

30%

Sunshine and air clarity?

Little or no sun. Visibility good at times below cloud, but misty or widely murky in rain.

How Cold? (at 900m)

11 to 13C.

Freezing Level

Above the summits

Viewing Forecast For

Eryri / Snowdonia National Park
Monday 21st July 2025
Last updated Fri 18th Jul 25 at 4:17PM

How windy? (On the summits)

Direction variable, typically below 10mph, but occasional sudden gusts around rain. Possibly becoming W-SW'ly 15-20mph.

Effect of the wind on you?

Mostly small

How Wet?

Bursts of rain, risk thunder

Areas of patchy rain, heavy showery bursts likely developing with a risk of thunder, may merge into frequent rain, though some places could escape drier for periods.

Cloud on the hills?

Varied cloud, but often covering hills

Varied patches of cloud in the morning. Mostly confined to upper slopes by mid-late morning, some breaks, but often capping tops. Lowering in rain, ragged patches from lower slopes upward.

Chance of cloud free summits?

40%

Sunshine and air clarity?

Mostly little sun, breaking through briefly. Visibility very good for periods, but reduced in rain, poor at times.

How Cold? (at 900m)

10 or 11C, small variation all day.

Freezing Level

Above the summits

Planning Outlook

Unsettled onward into early next week, as slack low pressure drifts slowly over the British Isles. Slow-moving showers and areas of persistent heavier rain in places, increasingly thundery downpours, these most extensive over England and Wales by Sunday. Staying fairly warm, quite humid. Often low wind speeds, but gusty south-southeasterlies at times. By mid-next week onward into late July, west to southwesterlies likely to prevail, with some rain or drizzle at times mostly western Scotland, often dry further south and east.