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.

Gales
Gale force winds (gusts over 50mph) make walking difficult and strenuous with a potential to be blown over by gusts. There is often a marked increase in winds through cols or on exposed ridges and summits. Distances can take longer to cover and compass bearings become harder to follow accurately.
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

Scattered showers for morning, then periods of rain from late afternoon. Summit winds relatively light by day.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Light rain showers (night) Light rain showers Sunny intervals Light rain Heavy Rain Heavy rain showers (night)
Chance of
precipitation
(at 800m)
Chance of precipitation
30%
30%
10%
30%
40%
40%

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 NW 27mph knots
NW
27mph
NW 20mph knots
NW
20mph
W 15mph knots
W
15mph
W 20mph knots
W
20mph
SW 32mph knots
SW
32mph
SW 39mph knots
SW
39mph
600m
600m NW 13mph knots
NW
13mph
NW 12mph knots
NW
12mph
W 12mph knots
W
12mph
SW 15mph knots
SW
15mph
SW 22mph knots
SW
22mph
SW 26mph knots
SW
26mph
300m
300m NW 7mph knots
NW
7mph
NW 8mph knots
NW
8mph
W 10mph knots
W
10mph
SW 11mph knots
SW
11mph
SW 13mph knots
SW
13mph
SW 17mph knots
SW
17mph
Valley
Valley NW 7mph knots
NW
7mph
NW 8mph knots
NW
8mph
W 10mph knots
W
10mph
SW 11mph knots
SW
11mph
SW 12mph knots
SW
12mph
SW 17mph knots
SW
17mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 32mph 23mph 20mph 25mph 39mph 48mph
600m
600m 18mph 15mph 16mph 20mph 29mph 35mph
300m
300m 16mph 13mph 15mph 18mph 25mph 31mph
Valley
Valley 17mph 13mph 15mph 17mph 23mph 31mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m -3 degrees Celsius -2 degrees Celsius 0 degrees Celsius -1 degrees Celsius 0 degrees Celsius 3 degrees Celsius
600m
600m 2 degrees Celsius 3 degrees Celsius 4 degrees Celsius 4 degrees Celsius 3 degrees Celsius 6 degrees Celsius
300m
300m 6 degrees Celsius 7 degrees Celsius 8 degrees Celsius 8 degrees Celsius 7 degrees Celsius 9 degrees Celsius
Valley
Valley 8 degrees Celsius 9 degrees Celsius 10 degrees Celsius 10 degrees Celsius 8 degrees Celsius 10 degrees Celsius
Freezing Level Freezing Level
1300m
1300m
1300m
1300m
3200m
3200m

Additional weather information

Meteorologist's view

Nothing to add

Weather

Some limited brighter spells mixed between a scattering of light showers during the morning. Cloud thickening from noon, with patchy rain late afternoon, which turns more persistent and at times heavy for the evening.

Chance of cloud-free hill tops

75% becoming 10-20% by late afternoon

Low cloud and visibility

Good or very good becoming moderate or poor in rain, very poor in cloud which thickens and lowers later in the day.

Ground conditions

No recent ground conditions report available.

Summit specific forecast