Mountain weather

Mountain weather

Eryri / Snowdonia

Confidence

High for unsettled, lowering for the transitional detail.

Sunrise: Sunset:
Sunrise: Sunset:
Mountain hazards

Mountain weather hazards

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

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.
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

Showers and rain developing at first. Turning drier, brighter for afternoon. Fresh winds.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Light rain Fog Sunny intervals Sunny intervals Sunny intervals Partly cloudy (night)
Chance of
precipitation
(at 800m)
Chance of precipitation
60%
20%
10%
10%
20%
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 NE 37mph knots
NE
37mph
E 29mph knots
E
29mph
SE 24mph knots
SE
24mph
SE 21mph knots
SE
21mph
SE 19mph knots
SE
19mph
SE 24mph knots
SE
24mph
600m
600m NE 16mph knots
NE
16mph
E 18mph knots
E
18mph
SE 18mph knots
SE
18mph
SE 13mph knots
SE
13mph
E 8mph knots
E
8mph
SE 12mph knots
SE
12mph
300m
300m N 9mph knots
N
9mph
E 7mph knots
E
7mph
SE 11mph knots
SE
11mph
SE 7mph knots
SE
7mph
NE 4mph knots
NE
4mph
SE 5mph knots
SE
5mph
Valley
Valley N 9mph knots
N
9mph
E 7mph knots
E
7mph
SE 11mph knots
SE
11mph
SE 7mph knots
SE
7mph
NE 4mph knots
NE
4mph
S 5mph knots
S
5mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 41mph 34mph 29mph 26mph 23mph 28mph
600m
600m 20mph 22mph 23mph 16mph 12mph 18mph
300m
300m 16mph 15mph 20mph 14mph 7mph 13mph
Valley
Valley 16mph 15mph 19mph 13mph 7mph 13mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m -4 degrees Celsius -2 degrees Celsius -1 degrees Celsius 0 degrees Celsius -1 degrees Celsius -2 degrees Celsius
600m
600m 1 degrees Celsius 2 degrees Celsius 3 degrees Celsius 4 degrees Celsius 4 degrees Celsius 3 degrees Celsius
300m
300m 5 degrees Celsius 7 degrees Celsius 8 degrees Celsius 9 degrees Celsius 8 degrees Celsius 6 degrees Celsius
Valley
Valley 6 degrees Celsius 9 degrees Celsius 10 degrees Celsius 11 degrees Celsius 9 degrees Celsius 8 degrees Celsius
Freezing Level Freezing Level
2100m
1800m
1500m
1400m
1300m
1300m

Additional weather information

Meteorologist's view

Difficult navigation at first in the extensive hill fog. Risk of severe wind chill confined to highest peaks.

Weather

A dull start to the week with occasional rain, then turning drier from mid-morning, to leave a largely dry afternoon, with some brighter spells developing.

Chance of cloud-free hill tops

20% becoming 75% for the afternoon

Low cloud and visibility

Good or very good, becoming moderate or poor in rain, very poor within cloud with bases quite extensive down to 600m at first, before lifting and breaking into the afternoon.

Ground conditions

No recent ground conditions report available.

Summit specific forecast