Snowdonia National Park Forecast

Viewing Weather Forecast for Friday 21st July 2017

Also includes higher summits south to Plynlimon.

Today | Saturday | Sunday

Forecast last updated on Friday 21st July 2017 at 7:18am

Summary for all mountain areas

Severe conditions on mountains near the Irish Sea as upland gales or severe gales (Wales) spread inland ahead of a band of heavy rain and low cloud. Winds will strengthen into Scotland, but low cloud and a little rain will be mostly confined to southern Scotland.

Headline for Snowdonia National Park

Upland gales or severe gales. Rain for several hours.

How windy? (On the summits)

Southerly, 40 to 50, perhaps locally 60mph. An easing to 20 or 25mph will spread slowly eastwards afternoon and early evening.

Effect of wind on you?

Walking very difficult across the hills most of day. You may be blown over where exposed on some crags and summits. Significant wind chill.

How Wet?

Rain; often heavy. ; clearing slowly east afternoon and evening

Widespread rain: initially rain 'on and off'. But slowly from west across west Wales will become persistent and frequently heavy. Through afternoon this will spread slowly to east Wales. In turn slowly from the west will clear to a few showers from mid or late afternoon onwards - but may never clear eastern hills until after dusk.

Cloud on the hills?

Persistent in slowly eastward moving band over several hours.

Very varied conditions: Broadly cloud confined to or above higher tops most or all morning. Then in rain, extensive fog above 500 to 700m, although northern Snowdon range, breaks above 900m. The deterioration may not reach E Wales until mid-afternoon. Then from west later afternoon cloud largely clearing again.

Chance of cloud free summits?


Sunshine and air clarity?

Patches sunshine edging inland later afternoon of evening when haze will clear and visibility become excellent.

How Cold? (at 900m)

8C. Will feel as cold as minus 4C directly in the wind.

Freezing Level

Above summits

Planning Outlook

All mountain areas of Britain from Saturday 22nd July 2017

This weekend and early next week, winds often light, some areas of low cloud and constant rain, but overall frequently dry (despite fairly low pressure). Least rain will be in northern Scotland. Nevertheless one or two areas of strong winds. A weak ridge of high pressure will bring mostly fine conditions to the mountains early next week, but further strengthening winds and rain are likely to spread east across Britain mid-week. From then rain and low cloud will be frequent, particularly western mountains.