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.
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.
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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.
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.
Viewing Forecast For
Eryri / Snowdonia National Park
Monday 29th December 2025
Last updated
Sun 28th Dec 25 at
2:58PM
Summary for all mountain areas
Chilly northeasterly winds with extensive cloud with patchy precipitation locally. Best breaks and sun western hills of England and Wales, and western Scotland. As a cold front edges south, cloud may break up more widely later for the Highlands with colder conditions developing on the hills.
Headline for Eryri / Snowdonia National Park
Chilly wind but mostly dry with western hills mostly clear. Cloud banks in east.
How windy? (On the summits)
Northeasterly 10 to 15mph, but tending to lift to 15 to 25mph through the day.
Effect of the wind on you?
Mostly small, but increasingly considerable wind chill where exposed to the wind.
How Wet?
No precipitation expected
Cloud on the hills?
Banks mostly across eastern hills.
Banks of low cloud may affect eastern hills with bases around 500-700m. Further west, much patchier cloud will the mountains mostly clear.
Chance of cloud free summits?
80% in west, 40% in east.
Sunshine and air clarity?
Cloudiest in the east, best sun in the west. Visibility mostly very good outside of any precipitation.
How Cold? (at 900m)
Around 0C
Freezing Level
Near or just below freezing above 500-700m, also frost some sheltered valleys in morning. Highest tops may reach 2C above an inversion.
Viewing Forecast For
Eryri / Snowdonia National Park
Tuesday 30th December 2025
Last updated
Sun 28th Dec 25 at
2:58PM
How windy? (On the summits)
East to north-easterly 10 to 20mph
Effect of the wind on you?
Mostly small
How Wet?
No precipitation expected
Cloud on the hills?
Patches confined to north and east.
Patches or banks some upper slopes in the north and east. Tending to lift off through the day. Otherwise, hills mostly clear.
Chance of cloud free summits?
60%
Sunshine and air clarity?
Broken cloud and sun. The sun best in the west. Visibility very good or excellent.
How Cold? (at 900m)
-2C
Freezing Level
600-700m
Viewing Forecast For
Eryri / Snowdonia National Park
Wednesday 31st December 2025
Last updated
Sun 28th Dec 25 at
2:58PM
How windy? (On the summits)
North-westerly 15mph at first, lifting to 20 to 30mph.
Effect of the wind on you?
Mostly small, but marked chill as wind picks up later.
How Wet?
No precipitation expected
Cloud on the hills?
Patchy coverage over tops.
Generally small amounts, other than a few patches on some tops. In the afternoon, in westerly airflow, banks may develop more widely over tops.
Chance of cloud free summits?
70% later 40%
Sunshine and air clarity?
Bright start with sun through high cloud, but cloud building from west. Visibility mostly very good or excellent.
How Cold? (at 900m)
-2C
Freezing Level
All levels at first, following widespread frost into valleys, but lifting to 500-700m.
Planning Outlook
Up until end of the year, high pressure still dominates. Significant change from New Year's Day as a cold front introduces, a much colder and strong northerly giving severe wind chill with temperatures well below average for the first week to the New Year with frequent and heavy snow showers moving into northern areas and running down coastal extremities with significant accumulations. Elsewhere, lots of dry and sunny weather, although occasional organised bands of snow will feed south at times in the Arctic airflow. All terrain becoming frozen, with scope for very low valley temperatures over snow cover when northerly flow eases.