Eryri / Snowdonia National Park
Includes all summits in the the northern half of Wales from Pumlumon northwards.
Sunday'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.
Cool to mild
Air temperature 5 to 10C 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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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.
Cool to mild
Air temperature 5 to 10C 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
Sunday 20th September 2026
Last updated
Sat 19th Sep 26 at
4:00PM
Summary for all mountain areas
Gale-force winds over Scottish mountains early in the day lessen, but staying blustery and feeling chilly, for northern areas in particular. Showery rain in the west in the morning fading. Cloud base rising with good breaks forming, sunny spells best toward east. Lightest winds for Wales.
Headline for Eryri / Snowdonia National Park
Strongest wind in morning; soon generally dry, cloud lifts.
How windy? (On the summits)
Westerly 25-35mph from dawn, tending to ease to 20mph by late morning, then 15mph or less into afternoon.
Effect of the wind on you?
Blustery and chilly early in the day, affecting comfortable walking and balance on exposed tops, moderating to become small into afternoon.
How Wet?
Little or no rain
Local drizzly showers possible over coastal hills early in day, but mostly dry. Some drizzle returns into the night in west.
Cloud on the hills?
Lifting and clearing
Patchy cloud above 700-800m in morning, most common near west coast. Lifting and clearing, but patches may come and go on higher western tops. Into night, blanket low cloud rolls in from west.
Chance of cloud free summits?
70%
Sunshine and air clarity?
Broken cloud and sunshine; high cloud tends to thicken to cover the sky. Some haze mostly toward coasts, very good visibility inland and east.
How Cold? (at 900m)
6 or 7C, little change all day, then tending to rise onward into night. Feeling sub-zero in early wind.
Freezing Level
Above the summits.
Viewing Forecast For
Eryri / Snowdonia National Park
Monday 21st September 2026
Last updated
Sat 19th Sep 26 at
4:00PM
How windy? (On the summits)
Westerly 25-30mph early in day, very gusty in places, but speeds tending to lessen during day to 15mph or less.
Effect of the wind on you?
Breezy, affecting ease of walking and balance on exposed tops for a time, but likely becoming smaller.
How Wet?
A little drizzle
Fine drizzle where in cloud feeling persistently damp, particularly western hills; drier toward the east.
Cloud on the hills?
Lowest west, high tops may be clear
Blanket cloud shrouding many western hills all day, to some lower slopes near Cardigan Bay. Highest tops may be near the top of the cloud sheet. Possibly more substantial breaks Carneddau and toward east.
Chance of cloud free summits?
30%
Sunshine and air clarity?
Some sun mostly develops in east and northernmost areas, in places may emerge into sunshine and clear air if above cloud, but staying misty poor visibility lower down.
How Cold? (at 900m)
12 to 14C, little change into night; quite humid.
Freezing Level
Above the summits.
Viewing Forecast For
Eryri / Snowdonia National Park
Tuesday 22nd September 2026
Last updated
Sat 19th Sep 26 at
4:00PM
How windy? (On the summits)
South to southwesterly 15 to 25mph, strongest around higher northwest tops, some notable gusty areas.
Effect of the wind on you?
Fairly small, but locally more blustery with some gusty spots starting to affect balance on exposed ridges.
How Wet?
Damp air, drizzle mostly west
Patchy drizzle mostly west coastal hills, feeling generally damp where in cloud. More often dry toward the north and east.
Cloud on the hills?
Low cloud most persistent near coast
Varied cloud and fog banks from dawn, covering hills and in some valleys; highest summits may be above most of the cloud. Banks tend to drift higher up and gradually thin, best north and east. Low cloud likely to linger west coast.
Chance of cloud free summits?
30%
Sunshine and air clarity?
Largely cloudy, misty or hazy; some sun breaking through north and east, also some sun and clear air possible for a time on high tops above cloud.
How Cold? (at 900m)
11 or 12C, humid; little change into evening, only slight drop into night.
Freezing Level
Above the summits.
Planning Outlook
Warm and humid air from the southwest extends across Britain early in the new week, cloaking many hills in fog and drizzle, to lower slopes near western coasts. A band of steadier rain is likely to be draped over northwest Scotland by Tuesday. Best of cloud breaks in areas further east and northeast. Rain then passes eastwards into Wednesday followed by a few showers, lower humidity and cloud bases lifting. Later in the week, areas of low pressure toward the northwest likely still bring periods of stronger winds to Scotland at least and a risk of rain at times mainly in the west, but a trend toward higher pressure and drier weather more often for the end of September into the start of October.