Eryri / Snowdonia National Park
Includes all summits in the the northern half of Wales from Pumlumon northwards.
Sunday's Forecast
Windy, walking impeded
Blustery conditions enough to give buffeting on higher terrain or affect balance on exposed ridges. 25 to 40mph.
Sunshine and showers
A good amount of dry and bright weather, but scattered bursts of rain, some may be locally heavy.
Chilly
Air temperature typically 1 to 5C on higher summits. Feeling distinctly chilly on tops when stationary or where exposed to wind. Take appropriate layers.
Flooding
Fast-flowing rivers and streams. Some routes may be impassable due to flooding.
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Windy, walking impeded
Blustery conditions enough to give buffeting on higher terrain or affect balance on exposed ridges. 25 to 40mph.
Sunshine and showers
A good amount of dry and bright weather, but scattered bursts of rain, some may be locally heavy.
Chilly
Air temperature typically 1 to 5C on higher summits. Feeling distinctly chilly on tops when stationary or where exposed to wind. Take appropriate layers.
Flooding
Fast-flowing rivers and streams. Some routes may be impassable due to flooding.
Viewing Forecast For
Eryri / Snowdonia National Park
Sunday 21st September 2025
Last updated
Sat 20th Sep 25 at
4:25PM
Summary for all mountain areas
Unusually cold temperatures for this time of year, feeling bitterly cold over the mountains where exposed to northerly winds, up to gale force in the Cairngorms in morning. Showers mostly northern Scotland early in day, falling as snow on Munros. Sunny spells elsewhere, a scattering of brief showers develop.
Headline for Eryri / Snowdonia National Park
Chilly, brisk wind. A few brief showers, some sun. Flooding.
How windy? (On the summits)
Northerly 25 to 30mph, occasionally 35mph higher exposed tops.
Effect of the wind on you?
Blustery over the mountains, affecting balance and comfortable walking. Considerable wind chill.
How Wet?
Occasional showers
Very wet underfoot, streams in spate, some flooding after recent heavy rain. Scattered showers mostly near coast in morning, tending to fade. One or two showers still possible afternoon.
Cloud on the hills?
Early cloud lifting and breaking
Cloud banks above 800m from dawn with patchy banks to mid-slopes in north. Cloud tends to lift and break, often exposing summits, though some patches may come and go on highest tops.
Chance of cloud free summits?
80%
Sunshine and air clarity?
Patchwork of sun and cloud, filling in for periods. Very good visibility.
How Cold? (at 900m)
3 or 4C. Feeling like -7 to -10C exposed to strongest wind on highest tops.
Freezing Level
Above the summits
Viewing Forecast For
Eryri / Snowdonia National Park
Monday 22nd September 2025
Last updated
Sat 20th Sep 25 at
4:25PM
How windy? (On the summits)
North-northeasterly 10-20mph, trending towards lower speeds as the day goes.
Effect of the wind on you?
Fairly small.
How Wet?
Rain unlikely
Small chance of a few light showers drifting onto northernmost mountains of Snowdonia NP.
Cloud on the hills?
Little cloud expected
Rare patches of cloud drifting over high tops of Snowdonia NP.
Chance of cloud free summits?
90%
Sunshine and air clarity?
Widely sunny, a little fair-weather cloud builds. Very good visibility.
How Cold? (at 900m)
3 or 4C.
Freezing Level
Above the summits
Viewing Forecast For
Eryri / Snowdonia National Park
Tuesday 23rd September 2025
Last updated
Sat 20th Sep 25 at
4:25PM
How windy? (On the summits)
North to northeasterly 10-15mph early morning, then 10mph or less afternoon.
Effect of the wind on you?
Mostly small.
How Wet?
Little or no rain
Local brief light showers toward northern coast early morning, an odd one drifting inland southwards during day.
Cloud on the hills?
Patchy cloud clearing
Cloud banks mostly over northern slopes from dawn, may cling to higher areas for a few hours, tending to thin, lift and break into middle of day, clearing most or all tops.
Chance of cloud free summits?
80%
Sunshine and air clarity?
Patchwork of cloud and sun; cloudier in north in morning. Visibility excellent.
How Cold? (at 900m)
4C rising to 6C afternoon.
Freezing Level
Pockets of frost some higher and lower sheltered slopes at dawn; otherwise above the summits.
Planning Outlook
High pressure expanding across the country for the start of the new week brings several days of dry weather and light winds for most places. Sunshine and patchy cloud, very clear air bringing excellent distant visibility. Chilly temperatures to start the week will slowly recover. Frosty dawns early in the week for many valleys and some sheltered higher terrain. Later in the week, southerly winds are expected to increase, drawing in much warmer air, but a risk of reaching gale-force with powerful gusts. Uncertain extent of rain possibly moving in from the southwest toward next weekend, possibly staying largely dry much of Scotland for longer.