Eryri / Snowdonia National Park
Includes all summits in the the northern half of Wales from Pumlumon northwards.
Saturday'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+
Heavy rain
Near-constant heavy rain, sometimes torrential over the mountains, very 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 8 to 12C on higher terrain. Comfortable temperatures on lower terrain, but feeling chilly if exposed to wind higher up, especially if stationary. Pack extra layers.
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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+
Heavy rain
Near-constant heavy rain, sometimes torrential over the mountains, very 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 8 to 12C on higher terrain. Comfortable temperatures on lower terrain, but feeling chilly if exposed to wind higher up, especially if stationary. Pack extra layers.
Viewing Forecast For
Eryri / Snowdonia National Park
Saturday 30th August 2025
Last updated
Fri 29th Aug 25 at
8:13PM
Summary for all mountain areas
Fine conditions in the morning for many, lasting well into the afternoon north and eastern Scotland, but southerly winds will be strengthening, to gale force soonest near to western coasts. Heavy rain sweeps in from the southwest, some thundery bursts mixed in. Deteriorating sooner in Wales.
Headline for Eryri / Snowdonia National Park
Wind rapidly increasing, heavy rain and gales.
How windy? (On the summits)
Southerly soon 30mph morning, rising to 60mph gusts 70mph middle of day. Later west-southwesterly 45-60mph.
Effect of the wind on you?
Deteriorating; walking rapidly becoming difficult, severe conditions for a time on higher terrain. Significant wind chill.
How Wet?
Heavy rain sets in during morning-middle of day; clearing later in day
Largely dry dawn, lasting longest further east, but rain sets in widely from west during morning, increasingly heavy with a risk of torrential downpours middle of day into afternoon, chance of thunder. Tending to break into showers later afternoon, drier into evening, but a few showers remain in west.
Cloud on the hills?
Extensive, breaking somewhat after rain
Varied cloud banks from dawn mostly in west, lifting for a time in morning, but filling in more extensively as rain sets in, covering hills from lower slopes up near coast, extensive above 600m inland. Late in day, as rain clears, cloud starting to lift and break.
Chance of cloud free summits?
30%, then almost nil in rain.
Sunshine and air clarity?
Weak sun at dawn soon gives way to thickening high cloud, soon overcast. Visibility initially good, becoming poor in rain; may improve late in day.
How Cold? (at 900m)
9C, rising in middle of day to 12C; cooling again later. Feeling below freezing in direct wind.
Freezing Level
Above the summits
Viewing Forecast For
Eryri / Snowdonia National Park
Sunday 31st August 2025
Last updated
Fri 29th Aug 25 at
8:13PM
How windy? (On the summits)
South to southwesterly 40 to 50mph, risk 60mph at least in gusts for periods over higher mountains.
Effect of the wind on you?
Arduous walking conditions widely, often difficult mobility on highest terrain, gusts could knock you over.
How Wet?
Heavy showers
Bursts of rain throughout the day, most frequent toward west coast early morning, but increasingly widespread. Risk of isolated thunder.
Cloud on the hills?
Varied over tops
Cloud base varying, often covering higher terrain above 800m, sometimes 600m toward coast, patches elsewhere in rain. Breaks occasionally higher up.
Chance of cloud free summits?
30%
Sunshine and air clarity?
Brief glimpses of sun. Visibility good away from showers, but general haze.
How Cold? (at 900m)
8 or 9C, little change all day. Wind chill feeling below freezing, near -5C in exposure on highest summits.
Freezing Level
Above the summits
Viewing Forecast For
Eryri / Snowdonia National Park
Monday 1st September 2025
Last updated
Fri 29th Aug 25 at
8:13PM
How windy? (On the summits)
South soon southwesterly, 30 to 40mph.
Effect of the wind on you?
Frequent buffeting, strenuous walking over exposed high terrain, affecting balance on ridges. Considerable wind chill.
How Wet?
Heavy showers, hail and thunder
Showery rain throughout the day, merging into clusters of more constant rain at times. Heavy bursts with hail, risk of lightning.
Cloud on the hills?
Rarely above high tops
Often covering higher slopes above 600-800m, most persistent west coastal areas, lowering in rain. Some breaks toward higher tops, but only briefly clearing.
Chance of cloud free summits?
20%
Sunshine and air clarity?
Rare brief glimpses of sun. Visibility intermittently good; but general haze, poor in rain.
How Cold? (at 900m)
8 or 9C. Feeling sub-zero directly in the wind on higher terrain.
Freezing Level
Above the summits
Planning Outlook
Low pressure continues to dominate early in the new week, maintaining unsettled conditions widely. Areas of rain and heavy showers, risk of hail and thunder. Windy, gales over mountains early in the week, tending to ease for periods at least in the Highlands mid-late week, whilst southwesterlies often remain strong over England and Wales. Some improvement possible toward next weekend, though the extended outlook into the second week of September remains changeable. Mid-September shows signs of a better improvement as pressure tends to rise more widely.