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.
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.
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.
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.
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
Monday 15th December 2025
Last updated
Sun 14th Dec 25 at
4:00PM
Summary for all mountain areas
A slow-moving area of rain affects England and Wales, heavy falls over south-facing hills, flooding likely. Drier for much of Scotland, though some showers affect the west coast; beware flooding after previous rain. Back just below freezing over higher Munros, some icy surfaces on tops.
Headline for Eryri / Snowdonia National Park
Rain often heavy, low cloud; gusty wind easing.
How windy? (On the summits)
Southwesterly 30-40mph from dawn, but easing during morning from west to 20-25mph, or less afternoon.
Effect of the wind on you?
Strenuous walking at first; feeling chilly. Tending to ease to small effects.
How Wet?
Rain most of the day, flooding
Rain continuing from overnight into the day, some steadier and heavier falls, though easing off at times more northwestern areas. Fading widely into evening. Very wet underfoot, streams in spate, expect flooding.
Cloud on the hills?
Fairly extensive
Shrouding the mountains widely, lowest west where reaching lower slopes near to coasts. Highest bases toward north of A5, local breaks above 800m.
Chance of cloud free summits?
20%
Sunshine and air clarity?
Overcast and dull. Visibility mostly poor due to rain, may improve far west.
How Cold? (at 900m)
3 or 4C. Feeling like -5C in strongest early wind.
Freezing Level
Above the summits
Viewing Forecast For
Eryri / Snowdonia National Park
Tuesday 16th December 2025
Last updated
Sun 14th Dec 25 at
4:00PM
How windy? (On the summits)
Westerly 10 to 20mph.
Effect of the wind on you?
Fairly small.
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?
Patchy cloud over tops
Patchy cloud banks most common nearer to coasts, may come and go above 600m, or 800m further inland. Breaks to tops more frequent hills near Bala.
Chance of cloud free summits?
40%
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
Sun 14th Dec 25 at
4:00PM
How windy? (On the summits)
South-southwesterly 45 to 60mph, powerful gusts in places 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.
Planning Outlook
Prolonged rain will leave flooding of streams and rivers in many mountain areas early in the new week, with the exception of northeastern Scotland. As a front clears Monday into Tuesday it will drop to freezing above 900m, beware of ice forming on higher Scottish mountains. Drier conditions for many on Tuesday, though showery near west coast of Scotland. By Wednesday, another system sweeps in from the Atlantic bringing further rain and gales. A risk of more heavy rain particularly England and Wales later in the week. A change of weather pattern is likely in the run up to Christmas, as high pressure builds northward, bringing drier weather, possibly chillier with time.