Mountain weather

Mountain weather

Eryri / Snowdonia

Confidence

High confidence for a cooler theme.

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.

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.

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

Hill fog clearing then sunny spells.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Cloudy Sunny intervals Sunny intervals Sunny Sunny Clear night
Chance of
precipitation
(at 800m)
Chance of precipitation
10%
10%
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 E 29mph knots
E
29mph
E 22mph knots
E
22mph
NE 18mph knots
NE
18mph
N 17mph knots
N
17mph
N 16mph knots
N
16mph
N 16mph knots
N
16mph
600m
600m NE 11mph knots
NE
11mph
NE 15mph knots
NE
15mph
NE 15mph knots
NE
15mph
N 16mph knots
N
16mph
N 12mph knots
N
12mph
N 7mph knots
N
7mph
300m
300m NE 7mph knots
NE
7mph
NE 10mph knots
NE
10mph
NE 11mph knots
NE
11mph
N 13mph knots
N
13mph
N 10mph knots
N
10mph
N 4mph knots
N
4mph
Valley
Valley NE 6mph knots
NE
6mph
NE 10mph knots
NE
10mph
NE 11mph knots
NE
11mph
N 13mph knots
N
13mph
N 10mph knots
N
10mph
N 4mph knots
N
4mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 37mph 28mph 23mph 23mph 21mph 22mph
600m
600m 20mph 20mph 20mph 21mph 17mph 12mph
300m
300m 16mph 18mph 18mph 20mph 17mph 11mph
Valley
Valley 15mph 17mph 17mph 20mph 17mph 11mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m -8 degrees Celsius -5 degrees Celsius -2 degrees Celsius -2 degrees Celsius -3 degrees Celsius -4 degrees Celsius
600m
600m -1 degrees Celsius 0 degrees Celsius 2 degrees Celsius 1 degrees Celsius 1 degrees Celsius 1 degrees Celsius
300m
300m 4 degrees Celsius 5 degrees Celsius 7 degrees Celsius 5 degrees Celsius 5 degrees Celsius 4 degrees Celsius
Valley
Valley 6 degrees Celsius 7 degrees Celsius 8 degrees Celsius 7 degrees Celsius 6 degrees Celsius 6 degrees Celsius
Freezing Level Freezing Level
900m
900m
1000m
1000m
900m
900m

Additional weather information

Meteorologist's view

Poor conditions to start, requiring good navigational skills. Otherwise, UV levels moderate to high with sun protection advised. Cold with layers required with feel like temperatures below freezing in the brisk winds.

Weather

Low cloud and hill fog first thing. This lifting then a bright day with sunny spells. Clear skies into the night with temperatures quickly falling away. Feeling cooler than of late, especially in the brisk northeasterly wind.

Chance of cloud-free hill tops

40% rising to 90%.

Low cloud and visibility

Fairly extensive low cloud down to 400-600m, especially to the south. This lifting and breaking. Poor visibility to start then improving to very good.

Ground conditions

Please see - https://yrwyddfa.live/

Summit specific forecast