Mountain weather

Eryri / Snowdonia

Eryri / Snowdonia Mountain weather forecast table

Confidence

Generally high confidence for the evolution. Moderate for extent of cloud later Sunday and the timing and location of precipitation on Monday and Tuesday. Low confidence by Thursday.

Sunrise:
Sunset:
Mountain hazards

Mountain weather hazards

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

hazard Poor Visibility
Poor visibility presents challenging route finding conditions. Visibility could be significantly less than 50 metres in all directions with few or no visual references, especially on featureless moors or plateaux. Distances become hard to judge and cliff or cornice edges can be difficult to recognise. These conditions require good navigational skills. There is a risk of white-out conditions when mist or fog is combined with extensive snow cover.
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.

Mountain weather forecast

Dry with sunny spells. Cloud thickening later with patchy rain late on

06:00 09:00 12:00 15:00 18:00 21:00
Weather
(at 800m)
Sunny intervals Cloudy Cloudy Cloudy Cloudy Partly cloudy (night)
Chance of precipitation
(at 800m)
<05% 10% 10% 20% 10% 20%

Wind direction and speed (mph)
Altitude above mean sea level
06:00 09:00 12:00 15:00 18:00 21:00
900m NE
11
NE
8
NE
9
NE
11
NE
12
NE
12
600m NE
6
NE
7
N
8
N
9
N
9
N
8
300m NE
2
N
4
N
5
N
7
N
5
N
3
Valley NE
2
N
4
NE
5
N
7
N
5
W
3
Wind gust (mph)
Altitude above mean sea level
06:00 09:00 12:00 15:00 18:00 21:00
900m 13 12 12 15 15 15
600m 7 10 12 13 12 11
300m 4 7 9 11 9 6
Valley 3 7 9 12 8 5

Altitude above mean sea level
06:00 09:00 12:00 15:00 18:00 21:00
900m
600m
300m
Valley
10°
10°
Freezing Level
1,400m
1,400m
1,400m
1,500m
1,500m
1,800m

Altitude above mean sea level
06:00 09:00 12:00 15:00 18:00 21:00
900m
-2°
600m
300m
Valley

Additional weather information

Meteorologist's view

Feeling chilly, especially across higher routes, despite spells of sunshine. Slight chance of moderate UV levels should cloud breaks persist. Note the possible deterioration in conditions later in the evening, with increasing low cloud amounts.

Weather

Largely dry day although patchy rain and drizzle is expected late on. An area of cloud will swing westwards through the morning, with bright spells in the west initially. Cloud breaks are expected to develop by late morning to give plenty of sunny spells. Sunshine turning increasingly hazy as high cloud increases during the afternoon. Cloud lowering later in the evening with some patchy light rain or drizzle possible towards Conwy late on. Chilly start under clear skies.

Chance of cloud-free hill tops

60% initially in the east, improving to 80% or above by late morning, best in the west. Lowering to 40% in the northeast later.

Low cloud and visibility

Areas of cloud down 500-600m during the early hours, cloud moving westwards around dawn but readily lifting and breaking to clear all summits. Cloud increasing from the north later with a chance of cloud shrouding higher routes in the northeast at times and bases lowering to 400m across for northern areas. Visibility often very good but may lower during the evening in any patchy drizzle, becoming poor or very poor.

Ground conditions

Please see - https://yrwyddfa.live/

Sunrise:
Sunset:

Mountain weather information

Weather

Widespread low cloud spreading across all areas overnight with outbreaks of mainly light rain and drizzle. This may turn persistent at times in the east of the Park leading to extensive hill fog. The worst of the rain likely clearing away eastwards by midday, but most probably leaving areas of low cloud and drizzle for much of the rest of the day.

Chance of cloud-free hill tops

Soon becoming 20%, perhaps increasing to 40% in the west during the afternoon.

Maximum wind speed expected

North to northwest 10-15 mph, gusting 20-25 mph.

Temperature

  • At 800m Plus 3 Celsius rising to Plus 5 Celsius.
  • Valley Plus 4 Celsius becoming plus 12 Celsius.
  • Freezing level Just above summits and rising.

Low cloud and visibility

Extensive cloud above around 400m, likely covering lower slopes towards the north and northeast during the morning. Visibility good outside of precipitation but poor to very poor in rain and drizzle. Cloud perhaps lifting later in the evening, and visibility improving a little.

Mountain weather information

Tue 23 Apr

Sunrise:
Sunset:

Any early low cloud and patchy rain clearing and breaking to leave a drier day with bright or sunny spells. Slight chance of an afternoon shower. Gentle northerly winds. Freezing level lowering to around 1000m.

Wed 24 Apr

Sunrise:
Sunset:

Likely dry with a mix of cloud and sunny spells. Any showers falling as a wintry mix at height. Light to moderate northerly or northwesterly winds. Feeling cold despite any sunny spells. Freezing level lowering to around 600m.

Thu 25 Apr

Sunrise:
Sunset:

Dry start with fair weather cloud developing. Becoming increasingly unsettled through the afternoon as an area of showers and rain pushes eastwards. Light to moderate northwesterly winds. Low confidence in details. Freezing level around 800m likely to rise above summits later.

Updated at:

Summit specific forecast

Mountain summit forecast map

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