Eryri / Snowdonia National Park
Includes all summits in the the northern half of Wales from Pumlumon northwards.
Tuesday'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.
Patchwork of cloud and sun
Dry most or all day. A mix of cloud and sunshine. Occasional cloud banks drifting over higher slopes, lifting above the tops.
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.
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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.
Patchwork of cloud and sun
Dry most or all day. A mix of cloud and sunshine. Occasional cloud banks drifting over higher slopes, lifting above the tops.
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
Tuesday 16th December 2025
Last updated
Mon 15th Dec 25 at
4:00PM
Summary for all mountain areas
Showery in western Scotland, with hail, snow on higher mountains; fewer showers eastwards, more sun and higher cloud breaks. Strongest winds in NW Highlands, up to gale force tops. England and Wales largely dry and bright, patchy cloud western tops.
Headline for Eryri / Snowdonia National Park
Light-moderate breeze. Dry with sun, cloud patches west.
How windy? (On the summits)
Westerly 10 to 20mph, least wind into early afternoon. Strengthening onward into night, well beyond midnight reaching 35-45mph.
Effect of the wind on you?
Fairly small. Deteriorating into night.
How Wet?
Largely dry
Chance of an odd light shower mainly near to the west coast. Very wet underfoot following previous heavy rain, streams in spate, flooding.
Cloud on the hills?
Patches on western tops
Patchy cloud banks most common nearer to coasts, may come and go above 700m, but well broken above tops further inland. Often clearer hills near Bala.
Chance of cloud free summits?
60%, to 80% well inland.
Sunshine and air clarity?
Occasional sun and thin high cloud. Visibility excellent out of cloud.
How Cold? (at 900m)
1 or 2C. Feeling like -4C directly in the breeze.
Freezing Level
Close to highest summits above 900m. Slight frost sheltered valleys in morning.
Viewing Forecast For
Eryri / Snowdonia National Park
Wednesday 17th December 2025
Last updated
Mon 15th Dec 25 at
4:00PM
How windy? (On the summits)
South-southwesterly 45 to 60mph, risk 70mph Snowdon group, powerful gusts downslope to north of higher tops.
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. Breaking up into showers into the evening. Renewed flooding likely.
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
Mon 15th Dec 25 at
4:00PM
How windy? (On the summits)
Southerly 35 to 50mph, but direction and speed may 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?
Risk of rain soon setting in
Dry possibly for a few hours in morning, bar an odd patch of rain near west coast. Risk of heavy rain moving in from south during day, possibly soon persistent.
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%
Sunshine and air clarity?
Overcast and dull, murky in rain.
How Cold? (at 900m)
3 or 4C. Wind chill feeling as cold as -10C on tops.
Freezing Level
Above the summits.
Planning Outlook
An unsettled southwesterly weather pattern continues mid-late this week. On Wednesday, another system sweeps in from the Atlantic bringing further rain and gales. Showery conditions then persist in western Scotland, with hail and snow on high tops. Scottish mountains often near or below freezing above 900m, only brief thawing higher up. Meanwhile, England and Wales stay mild midweek with more heavy rain likely into Thursday, then lowering to freezing on high tops for periods from Friday. A change of weather pattern is likely in the run up to Christmas, as high pressure builds northward, bringing drier weather, fog and frost more common.