Mountain weather

Mountain weather

Eryri / Snowdonia

Confidence

High for overall story, moderate for height of low cloud and any associated precipitation.

Mountain hazards

Mountain weather hazards

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

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.

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.

Mountain weather forecast

A cloudy day to start with some light rain possible, turning dry and fine by late morning.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Fog Cloudy Sunny intervals Sunny intervals Sunny Clear night
Chance of
precipitation
(at 800m)
Chance of precipitation
40%
30%
10%
10%
10%
10%

Wind direction and speed

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m W 13mph knots
W
13mph
W 15mph knots
W
15mph
W 16mph knots
W
16mph
W 16mph knots
W
16mph
NW 12mph knots
NW
12mph
W 8mph knots
W
8mph
600m
600m NW 10mph knots
NW
10mph
W 12mph knots
W
12mph
W 13mph knots
W
13mph
W 13mph knots
W
13mph
NW 10mph knots
NW
10mph
SW 7mph knots
SW
7mph
300m
300m NW 7mph knots
NW
7mph
W 9mph knots
W
9mph
W 11mph knots
W
11mph
W 10mph knots
W
10mph
W 8mph knots
W
8mph
S 3mph knots
S
3mph
Valley
Valley NW 7mph knots
NW
7mph
W 9mph knots
W
9mph
W 11mph knots
W
11mph
W 11mph knots
W
11mph
NW 8mph knots
NW
8mph
S 3mph knots
S
3mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 16mph 19mph 22mph 22mph 17mph 10mph
600m
600m 13mph 16mph 19mph 19mph 14mph 9mph
300m
300m 11mph 15mph 18mph 17mph 12mph 6mph
Valley
Valley 11mph 15mph 18mph 17mph 13mph 7mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 6 degrees Celsius 5 degrees Celsius 6 degrees Celsius 6 degrees Celsius 7 degrees Celsius 5 degrees Celsius
600m
600m 9 degrees Celsius 8 degrees Celsius 9 degrees Celsius 10 degrees Celsius 10 degrees Celsius 9 degrees Celsius
300m
300m 12 degrees Celsius 12 degrees Celsius 12 degrees Celsius 13 degrees Celsius 13 degrees Celsius 12 degrees Celsius
Valley
Valley 13 degrees Celsius 14 degrees Celsius 14 degrees Celsius 14 degrees Celsius 15 degrees Celsius 13 degrees Celsius
Freezing Level Freezing Level
2500m
2100m
1800m
1900m
1800m
1900m

Additional weather information

Meteorologist's view

Low cloud may make navigation at highest routes challenging initially with any precipitation making some surfaces slippery underfoot. Once cloud clears through the morning it will be a brilliant day to be in the National Park with plenty of dry weather and moderate winds. However UV-levels are expected to be high or very high so sun protection and plenty of water is advised.

Weather

A dull start initially with cloud and some rain or drizzle. This clearing through the morning to leave a fresher feel with sunny spells from late-morning onwards. Clear skies then into the night.

Chance of cloud-free hill tops

30% soon rising to 95%.

Low cloud and visibility

Low cloud initially with bases 400-600 m, rising above summits during the morning. Limited cloud into the afternoon. Poor visibility initially in any cloud or hill fog, but very good or excellent visibilities away from this with views of distant peaks possible.

Ground conditions

Please see - https://yrwyddfa.live/

Summit specific forecast