Eryri / Snowdonia National Park
Includes all summits in the the northern half of Wales from Pumlumon northwards.
Monday'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.
Patchy rain or drizzle
Rain on and off, or generally drizzly - total amounts small, but may be persistently damp, especially where hills are shrouded in cloud.
Warm
Comfortable temperatures on the hills, 10 to 15C on tops, feeling pleasantly warm especially on lower ground. Beware of feeling cooler if exposed to wind on higher terrain.
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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.
Patchy rain or drizzle
Rain on and off, or generally drizzly - total amounts small, but may be persistently damp, especially where hills are shrouded in cloud.
Warm
Comfortable temperatures on the hills, 10 to 15C on tops, feeling pleasantly warm especially on lower ground. Beware of feeling cooler if exposed to wind on higher terrain.
Viewing Forecast For
Eryri / Snowdonia National Park
Monday 17th August 2026
Last updated
Sun 16th Aug 26 at
3:56PM
Summary for all mountain areas
Much of the Highlands largely dry well into the afternoon with light winds, but some local patchy light rain and varied cloud. Rain develops from the west later, setting in heavy into evening. England and Wales sees patchy rain, drizzle and low cloud, though mid & south Wales tends to improve.
Headline for Eryri / Snowdonia National Park
Some light rain, low cloud, improving. Light-moderate breeze.
How windy? (On the summits)
Westerly 15-20mph in morning, often 20mph high tops at first; easing a little to 10-15mph middle of day, then rising later in day, to 25mph by dusk, 35mph into night.
Effect of the wind on you?
Fairly small, but later in day feeling breezier and may start to affect ease of walking toward sunset.
How Wet?
A little rain on and off, then heavy rain into night
Patchy light rain and drizzle in the morning and early afternoon, mostly small amounts, but hills nearer coasts may be often damp. May fade for a few hours afternoon, then into evening increasing risk steadier rain developing from northwest, but perhaps dusk onward before setting in - likely persistent heavy rain onward into night.
Cloud on the hills?
Lowest in morning, may persist high tops, breaks form inland
Fairly extensive cloud across the hills in morning above 500-700m, lowest toward northwest. Tending to rise with some breaks forming afternoon, mainly inland, higher western tops often capped. Lowering widely into evening.
Chance of cloud free summits?
30% rising to 50%, or 70% east
Sunshine and air clarity?
Largely cloudy, some weak sun occasionally through high cloud afternoon. Visibility varying, at times very good inland, but poorer around rain locally.
How Cold? (at 900m)
10C rising to if 13C out of cloud.
Freezing Level
Above the summits.
Viewing Forecast For
Eryri / Snowdonia National Park
Tuesday 18th August 2026
Last updated
Sun 16th Aug 26 at
3:56PM
How windy? (On the summits)
Westerly 20 to 30mph.
Effect of the wind on you?
Affecting comfortable walking on higher terrain, at times more strenuous in exposure. Marked wind chill.
How Wet?
A few showers
Heavy rain from overnight clears southward around dawn, leaving showery rain continuing on and off for a few hours, becoming scattered showers.
Cloud on the hills?
Early low cloud, may not clear west
Blanket cloud across hills from dawn, base tending to lift but likely to cap higher slopes much of day toward west; breaks east.
Chance of cloud free summits?
30% west rising to 60% inland
Sunshine and air clarity?
Cloud breaks to give sunny spells. Visibility improving to be very good.
How Cold? (at 900m)
9 or 10C, trending cooler later in day. Feeling near to freezing in the wind.
Freezing Level
Above the summits.
Viewing Forecast For
Eryri / Snowdonia National Park
Wednesday 19th August 2026
Last updated
Sun 16th Aug 26 at
3:56PM
How windy? (On the summits)
Southwesterly 20 to 30mph, may tend to increase later in day to often 30-35mph.
Effect of the wind on you?
Breezy over high terrain, affecting comfortable walking at times, risk buffeting more often later; feeling rather cool.
How Wet?
Showers
Showery rain most frequent in western areas in the morning, but scattered mostly brief bursts of rain passing eastwards during the day. Later a chance of more prolonged rain developing in the west.
Cloud on the hills?
Lifting with breaks toward tops
Covering many western tops above 600-800m in the morning; base tending to rise, breaks forming toward upper slopes, but patches may come and go on tops.
Chance of cloud free summits?
60%
Sunshine and air clarity?
Sun mostly east in the morning, otherwise often cloudy; some sun later near coast. Visibility mostly very good.
How Cold? (at 900m)
7 to 9C, coolest west, little change all day. Feeling near freezing directly in the wind.
Freezing Level
Above the summits.
Planning Outlook
Rain spreads to most places on Monday night as a frontal system moves eastward. Low pressure to the north will gradually drift south to envelop most of Britain into midweek, bringing showery conditions widely, some more organised bands of rain at times. Some heavy and thundery downpours forming, mostly into the afternoons in the second half of this week, becoming focused further south with time. Fresh westerly winds turning northerly and temperature lowering later in the week, dropping close to freezing on high Scottish tops by Friday and frost may occur in Highland glens over a couple of nights. Drier weather is likely by the weekend as higher pressure builds.