Mountain weather

Mountain weather

Eryri / Snowdonia

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Confidence

High confidence in the unsettled nature of the weather, lower confidence in the details of the precipitation such as timing and amount of rainfall.

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.
Updated: 
Mountain hazards explained

Mountain weather forecast

Unsettled with outbreaks of rain or showers and blustery winds.

Time
 Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
 Weather symbols Heavy Rain Light rain showers Sunny intervals Sunny intervals Light rain showers Cloudy
Chance of
precipitation
(at 800m)
 Chance of precipitation
90%
40%
40%
40%
60%
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 W 43mph knots
W
43mph
 W 40mph knots
W
40mph
 W 33mph knots
W
33mph
 W 33mph knots
W
33mph
 W 39mph knots
W
39mph
 W 36mph knots
W
36mph
600m
 600m SW 29mph knots
SW
29mph
 W 27mph knots
W
27mph
 W 25mph knots
W
25mph
 W 24mph knots
W
24mph
 W 25mph knots
W
25mph
 W 24mph knots
W
24mph
300m
 300m SW 19mph knots
SW
19mph
 W 18mph knots
W
18mph
 W 19mph knots
W
19mph
 W 17mph knots
W
17mph
 W 17mph knots
W
17mph
 W 16mph knots
W
16mph
Valley
 Valley SW 19mph knots
SW
19mph
 W 18mph knots
W
18mph
 W 19mph knots
W
19mph
 W 17mph knots
W
17mph
 W 17mph knots
W
17mph
 W 17mph knots
W
17mph

Wind gust

Altitude above mean sea level
Time
 Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
 900m 50mph 48mph 42mph 42mph 48mph 45mph
600m
 600m 36mph 35mph 33mph 32mph 33mph 32mph
300m
 300m 32mph 32mph 31mph 29mph 31mph 29mph
Valley
 Valley 32mph 32mph 31mph 29mph 31mph 30mph

Altitude above mean sea level
Time
 Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
 900m 5 degrees Celsius 5 degrees Celsius 0 degrees Celsius -1 degrees Celsius -2 degrees Celsius -3 degrees Celsius
600m
 600m 8 degrees Celsius 8 degrees Celsius 4 degrees Celsius 4 degrees Celsius 2 degrees Celsius 2 degrees Celsius
300m
 300m 10 degrees Celsius 11 degrees Celsius 8 degrees Celsius 8 degrees Celsius 6 degrees Celsius 6 degrees Celsius
Valley
 Valley 12 degrees Celsius 12 degrees Celsius 10 degrees Celsius 9 degrees Celsius 8 degrees Celsius 8 degrees Celsius
Freezing Level Freezing Level
3100m
2400m
1500m
1600m
1500m
1400m

Additional weather information

Meteorologist's view

Very poor walking conditions to start with poor visibility, the possibility of heavy rain and also gusty winds. Conditions will improve through the morning, though heavy showers will continue to be a possibility and the strong winds may make significant wind chill a possibility. Walkers should make sure they have waterproofs, layers and are careful where they tread. The winds will continue to be strong all day, so there may be some buffeting on the summits, and so this needs to be taken account of as well.

Weather

Cloudy to start with persistent rain, perhaps with some heavier bursts within it. This mostly clearing up by mid-morning to leave drier conditions and some sunny spells developing. By the afternoon there will be a risk of sporadic showers, which may be heavy at times. The showers are likely to continue overnight.

Chance of cloud-free hill tops

20%, becoming 80% by the afternoon.

Low cloud and visibility

Extensive low cloud expected at first with bases down to 300-400m, with a small chance of lower at 200-300m. This should slowly lift, and go above summits by late morning. Poor to poor visibility to start with hill fog likely, becoming generally good by the afternoon, although turning moderate to poor in any showers thereafter.

Ground conditions

No recent ground conditions report available.

Summit specific forecast

The Eryri (Snowdonia) mountains are made up of 90 mountain peaks including the tallest mountain in Wales, Yr Wyddfa (Snowdon), standing at 1,085 metres.

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