Eryri / Snowdonia National Park
Includes all summits in the the northern half of Wales from Pumlumon northwards.
Tuesday's Forecast
Severe gale or storm, mobility very difficult
Severe conditions on the mountains, any movement very challenging, you may be blown over. 55-70mph+
Frequent or persistent rain
Steady rain fairly persistent, occasionally heavy, rather wet underfoot.
Poor visibility
Murky conditions with areas of fog shrouding the hills, making navigation challenging. Map and compass essential.
Cool to mild
Air temperature 5 to 10C on higher terrain. Comfortable temperatures on lower terrain, but feeling chilly if exposed to wind higher up, especially if stationary. Pack extra layers.
Flooding
Fast-flowing rivers and streams. Some routes may be impassable due to flooding.
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Severe gale or storm, mobility very difficult
Severe conditions on the mountains, any movement very challenging, you may be blown over. 55-70mph+
Frequent or persistent rain
Steady rain fairly persistent, occasionally heavy, rather wet underfoot.
Poor visibility
Murky conditions with areas of fog shrouding the hills, making navigation challenging. Map and compass essential.
Cool to mild
Air temperature 5 to 10C on higher terrain. Comfortable temperatures on lower terrain, but feeling chilly if exposed to wind higher up, especially if stationary. Pack extra layers.
Flooding
Fast-flowing rivers and streams. Some routes may be impassable due to flooding.
Viewing Forecast For
Eryri / Snowdonia National Park
Tuesday 9th December 2025
Last updated
Mon 8th Dec 25 at
4:00PM
Summary for all mountain areas
Severe conditions becoming widespread and lasting onward into the night and Wednesday - stormy conditions, hurricane-force winds on higher mountains. Heavy rain sweeping northwards across Scotland during the day, breaking up into showers for England & Wales; flooding likely.
Headline for Eryri / Snowdonia National Park
Stormy winds, heavy rain then showery.
How windy? (On the summits)
South later southwesterly, strengthening from overnight to 50-60mph before dawn, reaching 70mph with gusts 80mph+ over higher mountains in west, peak speeds likely middle of day into early afternoon, then slight lessening.
Effect of the wind on you?
Difficult mobility and significant chill factor across exposed terrain all day, the most severe conditions into middle of day, powerful gusts could knock you over even on some downslopes.
How Wet?
Early heavy rain then showers, flooding
Incessant heavy rain from overnight lingers after dawn. Rain breaks into showery bursts through morning, mostly west, some broader areas of rain returning. Beware fast-flowing streams and local floods.
Cloud on the hills?
Extensive, local improvements later
Blanket cloud from middle or lower slopes up through the morning, always lowest on western slopes. Breaks to middle slopes occurring afternoon, chance of breaks up to 700-800m Carneddau/east Wales.
Chance of cloud free summits?
Less than 10%, 20% east Wales later
Sunshine and air clarity?
Overcast and dull, some bursts of sun may come through in afternoon, mainly north/eastern hills. Poor visibility, may improve where rain fades, but staying hazy.
How Cold? (at 900m)
9 or 10C, sharply dropping afternoon towards 4C by nightfall. Feeling as cold as -10C in the wind.
Freezing Level
Above the summits
Viewing Forecast For
Eryri / Snowdonia National Park
Wednesday 10th December 2025
Last updated
Mon 8th Dec 25 at
4:00PM
How windy? (On the summits)
Southwesterly 40 to 50mph, risk gusts 60mph over higher mountains.
Effect of the wind on you?
Challenging walking conditions over the hills, difficult in places on higher terrain; considerable wind chill.
How Wet?
Showers
Showery rain on and off, most frequent western areas.
Cloud on the hills?
Frequently on western high tops
Cloud base varying, but often capping higher summits toward the west, better breaks north and east of Ogwen.
Chance of cloud free summits?
50%
Sunshine and air clarity?
Bursts of sun most frequent toward north/east. Slight haze west, poorer in showers.
How Cold? (at 900m)
3 or 4C. Wind chill feeling like -10C.
Freezing Level
Above the summits
Viewing Forecast For
Eryri / Snowdonia National Park
Thursday 11th December 2025
Last updated
Mon 8th Dec 25 at
4:00PM
How windy? (On the summits)
South-southwesterly 35 to 50mph, some uncertainty of peak speeds, risk 60mph higher tops in Snowdon group.
Effect of the wind on you?
Challenging walking conditions, risk remaining difficult over higher tops.
How Wet?
Little or no rain
Drizzly patches mostly areas on or nearest the Llyn peninsula.
Cloud on the hills?
Patchy cloud some slopes
Banks of cloud may linger around some slopes much of day, mainly south-facing areas. Toward the north of the A5, more likely the hills clearer.
Chance of cloud free summits?
50%
Sunshine and air clarity?
Sun best toward north. Possible haze or mist in places, otherwise visibility good.
How Cold? (at 900m)
4C, may start to drop into evening or night. Feeling like -7 to -10C in the wind.
Freezing Level
Above the summits
Planning Outlook
A very unsettled pattern as southwesterly winds prevail and low pressure systems move in from the Atlantic, sustained gales over the mountains, severe or stormy for periods. Temperatures only close to freezing on higher Scottish tops this week, even here will experience spells above freezing with thawing, leaving snow increasingly patchy, but beware some icy surfaces on the very highest tops where some refreezing occurs. Drier for most places on Thursday this week, otherwise rainfall will be frequent and heavy, sometimes showery with hail. Expect wet ground conditions and further flooding of streams and some rivers.