Mountain weather

Eryri / Snowdonia

Eryri / Snowdonia Mountain weather forecast table

Confidence

High in general themes, moderate on precise location of showers on Monday and extent of cloud cover throughout.

Sunrise:
Sunset:

This evening forecast

Fine and dry weather persisting with patchy cloud slowly dissipating.

Sunrise:
Sunset:
Mountain hazards

Mountain weather hazards

Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.

hazard Strong Sunlight
Harmful UV levels from sunlight increase with altitude giving a greater risk of sunburn and eye damage, even on some overcast days. On breezy days, the cooling effect of wind on exposed skin may disguise any feeling of sunburn until it is too late. If there is snow cover, glare increases the effect of UV rays especially on the eyes. It is advisable to wear sun block, protective clothing such as a long-sleeved top and hat and have good quality eye protection.

hazard Severe Chill Effect
Wind significantly lowers the ‘feels-like’ temperature relative to the actual temperature, with even moderate winds significantly adding to the chilling effect. Strong winds can result in a severe and debilitating wind chill many degrees below the actual temperature. This effect will be enhanced in rain or wet snow. Without protection, prolonged exposure could result in frost nip or frostbite on exposed parts of the body and/or hypothermia.

Mountain weather forecast

Another fine and dry start with showers developing later.

Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
Weather
(at 800m)
Clear night Partly cloudy (night) Partly cloudy (night) Sunny intervals Light shower (day) Light shower (day) Sunny intervals Partly cloudy (night)
Chance of precipitation
(at 800m)
<05% <05% <05% <05% 20% 30% 20% 10%

Wind direction and speed (mph)
Altitude above mean sea level
Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
900m E
10
E
9
E
8
E
7
SE
6
NE
6
E
12
E
17
600m E
7
E
7
E
7
E
5
N
6
N
6
E
8
E
10
300m E
4
E
5
SE
5
SE
4
N
5
N
5
E
6
E
5
Valley SE
3
SE
4
SE
5
E
4
N
6
NE
6
E
6
SE
4
Wind gust (mph)
Altitude above mean sea level
Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
900m 15 13 11 10 10 10 16 22
600m 12 10 9 8 10 9 12 15
300m 8 10 9 7 9 9 12 11
Valley 7 9 9 7 10 10 11 10

Altitude above mean sea level
Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
900m
600m
300m
Valley
10°
11°
10°
Freezing Level
900m
900m
800m
900m
1,000m
1,200m
1,100m
1,100m

Altitude above mean sea level
Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
900m
-4°
-4°
-3°
-1°
-3°
600m
300m
Valley
10°

Additional weather information

Meteorologist's view

An excellent day for any outdoor activities with plenty of sunshine to begin and with most areas remaining dry. Moderate UV should be considered with sun protection suggested. Despite UV and sunshine, temperatures will still be rather low with feels like temperatures near freezing at times, therefore warm layers are suggested.

Weather

A dry and fine start to the day as high pressure continues to dominate across the area. Any localised mist or fog patches in the valleys will likely clear away soon after dawn. Fair weather cloud likely to develop through the morning with increased cloud pushing in from the east later. There is the potential for an isolated shower through the afternoon, anywhere in the park, however many places will likely remain dry.

Chance of cloud-free hill tops

90% dropping to 80% through the afternoon as patchy cloud drifts close to the height of the summits.

Low cloud and visibility

Any mist or fog patches in valleys may briefly lift to 400-600m before clearing. Apart from this very good or excellent visibilities are expected with views to distant summits likely. Visibilities will be poor or very poor to begin in mist and fog patches, and may dip to good or moderate in any passing showers.

Ground conditions

Please see - https://yrwyddfa.live/

Sunrise:
Sunset:

Mountain weather information

Weather

Cloudy to start the day, cloud shrouding the highest peak to begin. Cloud then clears westward through the morning leaving a dry and bright afternoon with plenty of sunshine.

Chance of cloud-free hill tops

30% initially rising to 90% through the morning as cloud lift and breaks.

Maximum wind speed expected

Easterly 30-40mph.

Temperature

  • At 800m Minus 1 Celsius rising to Plus 5 Celsius.
  • Valley Plus 4 Celsius rising to Plus 13 Celsius.
  • Freezing level 700m initially rising above summits through the morning.

Low cloud and visibility

Cloud bases initially at 400-600m, leading to widespread hill fog but with highest peaks potentially above the cloud layer. Cloud then lifts and breaks through the morning rising above summits. Visibility initially very poor in any hill fog but very good or good away from this. Visibilities becoming very good or excellent through the afternoon with views of distant peaks possible.

Mountain weather information

Wed 22 Apr

Sunrise:
Sunset:

Patchy cloud around Wednesday morning, quickly clearing to leave a fine and dry day with plenty of sunshine. Strong to gale force easterly winds especially over high ground with a significant wind chill. Freezing level 800-1000m initially, rising above summits.

Thu 23 Apr

Sunrise:
Sunset:

Another day with some patchy cloud to start though less widespread than on Wednesday, once again quickly clearing to leave a fine and dry day with plenty of sunshine. Winds easing slightly to a fresh to strong easterly. Freezing level above summits.

Fri 24 Apr

Sunrise:
Sunset:

A similar day ahead with patchy cloud clearing to leave a sunny day. Much lighter winds than previous days, generally light to moderate easterly. Freezing level above summits.

Updated at:

Summit specific forecast

Mountain summit forecast map

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