Snowdonia National Park Forecast

Viewing Weather Forecast for Wednesday 11th December 2019

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

Today | Thursday | Friday

Forecast last updated on Wednesday 11th December 2019 at 4:20pm

Summary for all mountain areas

Extensively windy and cold, with frequent snow and hail on most, particularly western mountains. Whiteout in some areas, and lightning in places. Upland gales will be severe northern Scotland.

Headline for Snowdonia National Park

Upland wind often near gale. Frequent precipitation.

How windy? (On the summits)

Southwest, abruptly veering westerly, 30mph, but 35mph later morning and middle of day.

Effect of wind on you?

Walking at times arduous, especially morning.

How Wet? (Precipitation and its impact)

Snow and hail; sometimes almost constant. Lightning in places.

Frequent snow and hail showers, although for two or three hours, the precipitation will rarely cease, giving whiteout on higher areas and thunder in places. Mostly rain below 400m. Will tend to become drier from west in afternoon. Very wet underfoot.

Cloud on the hills?

Extensively covering higher areas

Cloud base continually changing; often shrouding areas above 700m, although fleeting clearing to higher tops. Fog abruptly below 450m near precipitation.

Chance of cloud free summits?


Air clarity (below cloud)

A few patches of sun between showers afternoon, mainly east Wales. Visibility very good outside showers, but very poor or appalling in snow.

How Cold? (at 900m)


Freezing Level

750m - some variation as precipitation comes and goes.

Planning Outlook

All mountain areas of Britain from Thursday 12th December 2019

Cold, intermittently windy and extensive snowfall on most mountain areas during the next week. Only occasionally will snow penetrate to affect access roads; nevertheless, snow will accumulate on many lower slopes. Generally precipitation will be focussed on western mountains; some eastern summits substantially dry.