Eryri / Snowdonia National Park
Includes all summits in the the northern half of Wales from Pumlumon northwards.
Sunday's Forecast
Light wind, negligible impact
Little wind or walking hardly affected by the wind, but feeling chilly if exposed on tops. 10-15mph or less.
Dry, Inversion
Banks of cloud or fog on lower or middle slopes, but higher terrain likely clear and sunny above an inversion.
Warm
Comfortable temperatures on the hills, 10 to 15C on tops, feeling pleasantly warm especially on lower ground. Beware of feeling cooler if exposed to wind on higher terrain.
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Light wind, negligible impact
Little wind or walking hardly affected by the wind, but feeling chilly if exposed on tops. 10-15mph or less.
Dry, Inversion
Banks of cloud or fog on lower or middle slopes, but higher terrain likely clear and sunny above an inversion.
Warm
Comfortable temperatures on the hills, 10 to 15C on tops, feeling pleasantly warm especially on lower ground. Beware of feeling cooler if exposed to wind on higher terrain.
Viewing Forecast For
Eryri / Snowdonia National Park
Sunday 12th October 2025
Last updated
Sat 11th Oct 25 at
4:00PM
Summary for all mountain areas
A glorious day for the hills in most places; sunshine and feeling noticeably warm above an inversion - fog in valleys and covering some lower hill slopes in the morning. Some patchy cloud drifting higher up, mainly toward northwest of the Highlands. Mostly light variable wind, locally some gusts, easterlies for Wales.
Headline for Eryri / Snowdonia National Park
Inversion on the mountains. Warm sun. Mostly light wind.
How windy? (On the summits)
East to southeasterly 10-15mph or less. Gusty over tops and elevated passes, locally 20mph later in day.
Effect of the wind on you?
Mostly small.
How Wet?
No rain expected
Cloud on the hills?
Early valley fog, tops above mid-level patches, all clearing afternoon.
Fog in the valleys from dawn, most extensive towards east and mid-Wales. This lifting after sunrise and dissipating though ribbon-like cloud banks will cling to eastern middle slopes for a few hours then likely to largely clear. High tops cloud-free all day.
Chance of cloud free summits?
90% (above fog in morning); almost certain all terrain afternoon.
Sunshine and air clarity?
Often sunny though some high cloud will weaken its strength. Excellent visibility on the summits above haze or early fog on lower slopes.
How Cold? (at 900m)
12C. Little change or slight rise in temperature with increased altitude, 14C in places on high tops. Low terrain much cooler than hills early in day.
Freezing Level
Above the summits
Viewing Forecast For
Eryri / Snowdonia National Park
Monday 13th October 2025
Last updated
Sat 11th Oct 25 at
4:00PM
How windy? (On the summits)
Southeasterly 10-15mph, occasional 20mph. Notable gusts over summits and elevated passes.
Effect of the wind on you?
Mostly small.
How Wet?
No rain expected
Cloud on the hills?
Mid-level cloud, mostly eastern slopes
Low fog from dawn fairly extensive over Berwyn group and eastern parts of Snowdonia NP, some cloud on middle slopes. Cloud lifts with patches between 500-800m, at times more sheet-like in the east. Terrain above 800m likely above cloud layer.
Chance of cloud free summits?
70% (high summits above cloud)
Sunshine and air clarity?
Often sunny on high tops, more mixed lower terrain, possibly quite cloudy east. Excellent visibility above cloud, hazy lower down.
How Cold? (at 900m)
11C, little change with height. Valleys starting much cooler.
Freezing Level
Above the summits
Viewing Forecast For
Eryri / Snowdonia National Park
Tuesday 14th October 2025
Last updated
Sat 11th Oct 25 at
4:00PM
How windy? (On the summits)
Easterly 10 to 15mph, in places gusty 20mph around some mountains, not necessarily on the summits.
Effect of the wind on you?
Mostly small
How Wet?
No rain expected
Cloud on the hills?
Patchy cloud, inversion; clearer west
Varied valley fog and cloud banks on some slopes in morning, high tops likely start above the cloud layer. Cloud tending to drift higher up, and may cover higher slopes at times. Clearer overall in west.
Chance of cloud free summits?
60% (above cloud banks for a time)
Sunshine and air clarity?
Sunshine generally best in west Wales. The air very clear if above the cloud. Some mist lower down in morning.
How Cold? (at 900m)
9C, small variation from lower slopes upward in morning, whilst highest tops a degree or so warmer all day.
Freezing Level
Above the summits
Planning Outlook
High pressure continues to reside over the country into the new week maintaining quiet weather. Varied low cloud and morning fog. Inversion conditions likely to remain over higher mountains for several days, then during midweek this may start to weaken as pressure begins to fall gradually. Light winds overall, an easterly breeze likely for Wales early-midweek. Uncertainty about the weather pattern development toward next weekend, some indication of strengthening south-southwesterly winds bringing some rain, but may not reach all areas. Later October has hints of chillier northerly air, especially in Scotland.