Eryri / Snowdonia National Park
Includes all summits in the the northern half of Wales from Pumlumon northwards.
Wednesday's Forecast
Gale force, walking arduous
Considerable buffeting, walking into the wind will be strenuous on exposed terrain, stronger gusts may knock you off your feet. 40 to 55mph.
Heavy rain
Near-constant heavy rain, sometimes torrential over the mountains, very wet underfoot.
Poor visibility
Murky conditions with areas of fog shrouding the hills, making navigation challenging. Map and compass essential.
Chilly
Air temperature typically 0 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.
Click an icon for more information or click here for a key to all icons.
Gale force, walking arduous
Considerable buffeting, walking into the wind will be strenuous on exposed terrain, stronger gusts may knock you off your feet. 40 to 55mph.
Heavy rain
Near-constant heavy rain, sometimes torrential over the mountains, very wet underfoot.
Poor visibility
Murky conditions with areas of fog shrouding the hills, making navigation challenging. Map and compass essential.
Chilly
Air temperature typically 0 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
Wednesday 17th December 2025
Last updated
Tue 16th Dec 25 at
4:20PM
Summary for all mountain areas
Extensive gales across the hills. Rain preceded by early snow on higher terrain in the Highlands, lifting briefly above freezing to high tops. Showery bursts follow into western Scotland, heavy and frequent with hail later. England & Wales sees rain much of the day, spreading eastward, heavy at times.
Headline for Eryri / Snowdonia National Park
Upland gales, severe high tops. Heavy rain, low cloud.
How windy? (On the summits)
South-southwesterly 45 to 60mph, risk 70mph Snowdon group, powerful gusts downslope to north of higher tops. Lessening a little only late evening into night.
Effect of the wind on you?
Challenging conditions over the hills, walking difficult in places higher up, sudden buffeting to some mid-slopes.
How Wet?
Rain most of day, often heavy
Rain soon setting in from dawn, persistent widely much of the day, heaviest western areas. Into the evening, an intense band of rain, then breaking into showers into night. Very wet underfoot, streams in spate, renewed flooding likely later.
Cloud on the hills?
Extensive
Shrouding the hills widely all day, from mid-to-lower slopes western areas, but rarely above any higher tops, best chance north of A5 and toward Berwyn/Bala groups.
Chance of cloud free summits?
10%
Sunshine and air clarity?
Overcast and murky, particularly west.
How Cold? (at 900m)
1 or 2C rising during day to 5C. Feeling like -8 to -12C directly in the wind.
Freezing Level
Above the summits, but close to very highest tops above 1000m early in day.
Viewing Forecast For
Eryri / Snowdonia National Park
Thursday 18th December 2025
Last updated
Tue 16th Dec 25 at
4:20PM
How windy? (On the summits)
Southerly 35 to 50mph, but direction and speed likely to vary, possibly lower speeds for periods during day.
Effect of the wind on you?
Expect arduous walking conditions and considerable wind chill on higher terrain, but may lessen for periods.
How Wet?
Heavy rain soon setting in
Dry possibly for a few hours from dawn, bar an odd patch of rain near west coast. Heavy rain moving in from south, possibly soon persistent. Breaking up into showery rain (also hail, snow high tops) evening into night.
Cloud on the hills?
Fairly extensive
Banks of cloud varying, most persistent south-facing slopes. Widely filling in if rain sets in. Best higher breaks Carneddau.
Chance of cloud free summits?
30% at first, dropping below 10%
Sunshine and air clarity?
Overcast and dull, murky in rain.
How Cold? (at 900m)
3 or 4C, then lowering to 0C into night. Wind chill feeling as cold as -10C on tops.
Freezing Level
Above the summits, then dropping into the night to around 900m.
Viewing Forecast For
Eryri / Snowdonia National Park
Friday 19th December 2025
Last updated
Tue 16th Dec 25 at
4:20PM
How windy? (On the summits)
Southwesterly 35 to 50mph, strongest northern tops in the morning, tending to lessen a little during day.
Effect of the wind on you?
Arduous conditions over higher mountains, frequent buffeting in exposure in morning. Significant wind chill.
How Wet?
Occasional showers with hail
Passing showers mostly morning, with hail briefly, falling as snow above 800m. Fading to be brief or rare afternoon.
Cloud on the hills?
Mostly high tops with breaks
Varying cloud bases, but often capping high tops above 800m in morning, some breaks more often afternoon. Clearer well inland and east Wales much of day.
Chance of cloud free summits?
50%
Sunshine and air clarity?
Bursts of sun, most frequent east. Visibility mostly very good.
How Cold? (at 900m)
0 to 2C. Feeling like -12C directly in the wind.
Freezing Level
900 to 1000m, rising slightly just above tops later or after dark.
Planning Outlook
South-southwesterly winds widely remain gale force over the mountains later this week and through into Saturday, severe upland gales for periods. More heavy rain for England and Wales on Thursday, further flooding expected; rain spreads north into Scotland, falling as snow on Munros. Showery by Friday, most frequent in western Scotland with hail, also snow over tops. Another belt of persistent rain likely arrives from the west into Saturday, snow only highest Scottish tops. A switch to east-southeasterly winds by Sunday into early next week, some residual rain and high-level snow, but a drier theme develops and favouring chillier conditions into the Christmas period.