Mountain weather

Mountain weather

Eryri / Snowdonia

Confidence

High for mobile westerly pattern bringing occasional unsettled conditions. Lowering for the timing of the later worst of weather.

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

Brighter spells and building showers. Winds strengthening.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Light rain Mist Light rain showers Heavy rain showers Light rain showers Light rain showers (night)
Chance of
precipitation
(at 800m)
Chance of precipitation
40%
10%
30%
40%
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 N 27mph knots
N
27mph
NW 24mph knots
NW
24mph
NW 23mph knots
NW
23mph
NW 22mph knots
NW
22mph
NW 26mph knots
NW
26mph
NW 31mph knots
NW
31mph
600m
600m N 14mph knots
N
14mph
NW 16mph knots
NW
16mph
NW 19mph knots
NW
19mph
NW 17mph knots
NW
17mph
NW 15mph knots
NW
15mph
NW 18mph knots
NW
18mph
300m
300m N 10mph knots
N
10mph
NW 12mph knots
NW
12mph
NW 14mph knots
NW
14mph
NW 13mph knots
NW
13mph
NW 10mph knots
NW
10mph
NW 12mph knots
NW
12mph
Valley
Valley N 10mph knots
N
10mph
NW 12mph knots
NW
12mph
NW 15mph knots
NW
15mph
NW 13mph knots
NW
13mph
NW 11mph knots
NW
11mph
NW 13mph knots
NW
13mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 34mph 29mph 29mph 29mph 32mph 37mph
600m
600m 20mph 21mph 25mph 23mph 20mph 24mph
300m
300m 20mph 20mph 23mph 21mph 19mph 23mph
Valley
Valley 20mph 20mph 23mph 22mph 20mph 24mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m -2 degrees Celsius -2 degrees Celsius -1 degrees Celsius -1 degrees Celsius -3 degrees Celsius -4 degrees Celsius
600m
600m 3 degrees Celsius 2 degrees Celsius 3 degrees Celsius 3 degrees Celsius 1 degrees Celsius 1 degrees Celsius
300m
300m 7 degrees Celsius 7 degrees Celsius 7 degrees Celsius 7 degrees Celsius 5 degrees Celsius 5 degrees Celsius
Valley
Valley 9 degrees Celsius 8 degrees Celsius 9 degrees Celsius 9 degrees Celsius 7 degrees Celsius 7 degrees Celsius
Freezing Level Freezing Level
2000m
1300m
1400m
1300m
1300m
1300m

Additional weather information

Meteorologist's view

Nothing to add

Weather

A cloudy start to the day with some patchy rain possible, but soon clearing to lead a mix of brighter spells and scattered showers from the morning. Showers building for the afternoon, before dwindling for the evening.

Chance of cloud-free hill tops

40% becoming 70% from mid-morning

Low cloud and visibility

Good or very good becoming moderate or poor in rain, very poor in cloud with bases quite extensive at first, then occasionally lowering 600m from mid-morning, particularly as the showers push through.

Ground conditions

No recent ground conditions report available.

Summit specific forecast