Eryri / Snowdonia National Park
Includes all summits in the the northern half of Wales from Pumlumon northwards.
Thursday's Forecast
Windy, walking impeded
Blustery conditions enough to give buffeting on higher terrain or affect balance on exposed ridges. 25 to 40mph.
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.
Hazy, some fog banks
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Distant views reduced by haze, locally foggy for a time in valleys and some hill slopes.
Very warm
Warm conditions across the hills, rising above 15C on tops. Increasingly hot on lower terrain, reaching 25C+ in many valleys. Beware of dehydration.
Strong warm sunshine
High UV levels, feeling very warm when ascending, beware of dehydration and sunburn.
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Windy, walking impeded
Blustery conditions enough to give buffeting on higher terrain or affect balance on exposed ridges. 25 to 40mph.
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.
Hazy, some fog banks
Distant views reduced by haze, locally foggy for a time in valleys and some hill slopes.
Very warm
Warm conditions across the hills, rising above 15C on tops. Increasingly hot on lower terrain, reaching 25C+ in many valleys. Beware of dehydration.
Strong warm sunshine
High UV levels, feeling very warm when ascending, beware of dehydration and sunburn.
Viewing Forecast For
Eryri / Snowdonia National Park
Thursday 28th May 2026
Last updated
Wed 27th May 26 at
4:15PM
Summary for all mountain areas
Gusty winds, warm and humid, a mix of strong sun and high cloud - the warmest day this week for the Highlands, but locally low cloud southeast. Northern England starts with a risk of thunderstorms, but clearing. An isolated thunderstorm possible for Highlands, mainly NW later. Low cloud near west coast of Wales.
Headline for Eryri / Snowdonia National Park
Increasingly windy. Warm sun, hazy; west coast low cloud.
How windy? (On the summits)
Southerly, 20 to 30mph in morning, but risk stronger and gustier up to dawn. Generally strengthening into afternoon, rapidly reaching 40mph over western mountains, with stronger gusts toward 50mph for a time by evening, moderating a little from dusk into night.
Effect of the wind on you?
Blustery in morning, but deteriorating to more strenuous walking conditions, later afternoon into evening considerable buffeting making balance challenging in exposure.
How Wet?
Some coastal drizzle develops
Remnants of any overnight thundery rain likely clear before dawn. Some fine drizzle develops over west coastal hills as low cloud rolls in.
Cloud on the hills?
Low cloud may fill in west coast, little N & E; high mountains possible inversion.
Largely clear morning, bar odd fragments or mist in valleys at first. During middle of day, low cloud / fog likely rolls in from Cardigan Bay over hills near coasts to lower slopes, may vary in extent afternoon, some cloud banks drift inland, but high tops above 800m likely near / above top of cloud. North / east hills stay clearer overall.
Chance of cloud free summits?
50% west coasts, 90% north and east.
Sunshine and air clarity?
Varied sun and thin high cloud, plus lower level cloud and mist especially west coast. Beware sunburn and dehydration if in stronger sun. Generally very hazy even away from cloud.
How Cold? (at 900m)
14 to 16C, small change from dawn into day; cooling to 10C if in cloud and more generally 8C into evening-night. Feeling much cooler, later near 0C where directly in the stronger wind.
Freezing Level
Well above the summits.
Viewing Forecast For
Eryri / Snowdonia National Park
Friday 29th May 2026
Last updated
Wed 27th May 26 at
4:15PM
How windy? (On the summits)
Southwesterly 20 to 30mph.
Effect of the wind on you?
Breezy over higher exposed terrain, noticeably affecting balance on ridges; rather cool.
How Wet?
Rain rare if any
Chance of a brief drizzly shower west coastal areas in the morning.
Cloud on the hills?
Most common over west coast hills
Banks of cloud over hills, may come and go toward coast above 600-800m. Higher bases north and eastward, breaks above the summits. Tending to break up with time.
Chance of cloud free summits?
50% rising to 80%
Sunshine and air clarity?
A little sun mostly toward east. Visibility good below cloud, hazier west coastal areas.
How Cold? (at 900m)
8 or 9C. Wind chill feeling near 0C on high tops.
Freezing Level
Above the summits.
Viewing Forecast For
Eryri / Snowdonia National Park
Saturday 30th May 2026
Last updated
Wed 27th May 26 at
4:15PM
How windy? (On the summits)
South to southwesterly 20 to 30mph, tending to strengthen, may reach 40mph at least in gusts on higher tops.
Effect of the wind on you?
Increasingly affecting ease of walking, becoming strenuous on high terrain. Marked wind chill on exposed tops.
How Wet?
Some rain develops from west
Largely dry morning or longer, but increasing risk with time into afternoon of patchy rain moving in from west, possibly becoming more persistent later in west.
Cloud on the hills?
Mostly little, lowering over tops later
Some patchy cloud banks mostly hills near west coasts in morning, but many hills clear. As rain develops later, cloud lowering over hills from west, later may fill in to 600m, or lower near west coast.
Chance of cloud free summits?
80% dropping to 30% later
Sunshine and air clarity?
Occasional sun then high cloud builds; cloudier and dull later in day. Visibility very good, reducing later in rain.
How Cold? (at 900m)
9 or 10C. Wind chill feeling near/below 0C on tops.
Freezing Level
Above the summits.
Planning Outlook
Gale or near-gale force southwesterlies on Friday for the Highlands, strongest toward the northwest, where accompanied by rain, drizzle and low cloud. Nearer average temperatures for all into the weekend onward as changeable southwesterlies prevail - a generally unsettled theme is expected during the first ten days of June with lower pressure dominating. Frontal systems come in from the Atlantic - rain, drizzle and low cloud most common on western coastal mountains, but showery days are likely more widely at times, possibly rain more widely further south later in week. Wind speeds will vary, but reaching gale force on mountains for periods.