Includes all summits in the the northern half of Wales from Plynlimon northwards.
Snowdonia National Park
Monday 20th September 2021
Last updated
Sun 19th Sep 21 at
3:49PM
Low cloud and generally damp conditions will affect western Scotland. Total rainfall small, although some steadier rain will develop as a front moves in. SW'ly winds strongest in the far north. Elsewhere a fine day with broken cloud and sun, some early fog patches.
Dry, hills generally clear, sunshine.
Northerly 10 to locally 15mph.
Small
No rain
Little if any
Most cloud confined above higher tops. Some early fog banks in valleys.
90%
Sunshine and a little fair-weather cloud forming. Mostly excellent visibility; early low level fog.
8C
Above the summits.
Snowdonia National Park
Tuesday 21st September 2021
Last updated
Sun 19th Sep 21 at
3:49PM
West becoming southwesterly, 10 to 15mph, may reach 20mph later.
Mostly small
Rain unlikely
Rare if any pockets of fine drizzle if around low cloud in west.
Occasional low cloud west
Banks of low cloud may drift onto hills nearest Cardigan Bay from time to time, although many hills often clear, with higher summits probably above lower cloud.
70%
Sunshine and high level cloud. Visibility good, but a slight haze.
11C; hills warmer than valleys at first.
Above the summits
Snowdonia National Park
Wednesday 22nd September 2021
Last updated
Sun 19th Sep 21 at
3:49PM
Southwesterly, 25 to 35mph, but may approach 50mph for a few hours, particularly Snowdon range.
Expect arduous walking conditions on higher mountains much of the day. Notable wind chill where exposed.
Risk of rain developing
Initially mainly dry, but patchy light rain likely moving onto western coastal hills. Increasing risk of steadier rain developing as a front moves in from the northwest (timing uncertain).
Mostly west; extensive if rain sets in.
Banks of low cloud focused on hills nearest Cardigan Bay in the morning, but well broken further inland. If rain develops, cloud will broadly lower to blanket the hills, to lower slopes in west, but mostly above 600m in east.
20% west, to 50% east.
Occasional sun, mostly east Wales. Visibility good below cloud, but west coasts may become misty.
8 to 11C, lowest if in cloud.
Above the summits
High pressure will drift southwards and southwesterly winds will strengthen across Britain in the first half of the week, soonest across Scotland. Staying windy through into next weekend, gales or sometimes severe gales on higher mountains, particularly Scotland. Rain will become frequent in western Scotland as fronts come in from the Atlantic. Spells of rain elsewhere - less wet for Wales and southern Pennines, although a risk of heavier rain moving further south by the weekend. Temperatures will vary through the next 10 days, sometimes fairly warm and humid, but chiller air spreading from the northwest at times - Scottish high tops occasionally near freezing point.