Mountain weather

Mountain weather

Eryri / Snowdonia

Confidence

High for overall changeable theme but low for intensity and clearance of rain on Saturday.

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.
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.
Heavy Persistent Rain
Heavy and persistent rain can lead to drenched clothing and footwear with waterproofs often becoming soaked through, especially if accompanied by strong winds. This can lead to significant loss of body heat and an increased likelihood of hypothermia. Terrain may turn increasingly boggy underfoot while streams can flood and become impassable. There may also be a risk of flooding in valleys or glens. If there is snow cover, a heightened avalanche hazard is possible and avalanche reports should be consulted where available.

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.

Mountain weather forecast

Wet and very windy today. Gales expected on higher slopes and ridges.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Light rain Heavy Rain Heavy Rain Heavy Rain Light rain Light rain
Chance of
precipitation
(at 800m)
Chance of precipitation
40%
90%
≥95%
90%
70%
50%

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 SW 44mph knots
SW
44mph
SW 45mph knots
SW
45mph
SW 41mph knots
SW
41mph
SW 35mph knots
SW
35mph
SW 29mph knots
SW
29mph
W 21mph knots
W
21mph
600m
600m SW 29mph knots
SW
29mph
SW 30mph knots
SW
30mph
SW 25mph knots
SW
25mph
SW 23mph knots
SW
23mph
SW 19mph knots
SW
19mph
W 14mph knots
W
14mph
300m
300m S 18mph knots
S
18mph
SW 19mph knots
SW
19mph
SW 16mph knots
SW
16mph
SW 14mph knots
SW
14mph
SW 12mph knots
SW
12mph
SW 8mph knots
SW
8mph
Valley
Valley S 18mph knots
S
18mph
SW 18mph knots
SW
18mph
SW 16mph knots
SW
16mph
SW 14mph knots
SW
14mph
SW 11mph knots
SW
11mph
SW 8mph knots
SW
8mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 52mph 53mph 50mph 42mph 35mph 26mph
600m
600m 36mph 38mph 34mph 30mph 25mph 19mph
300m
300m 33mph 33mph 31mph 26mph 23mph 16mph
Valley
Valley 33mph 33mph 30mph 25mph 21mph 15mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 5 degrees Celsius 6 degrees Celsius 6 degrees Celsius 8 degrees Celsius 8 degrees Celsius 9 degrees Celsius
600m
600m 8 degrees Celsius 8 degrees Celsius 10 degrees Celsius 11 degrees Celsius 11 degrees Celsius 12 degrees Celsius
300m
300m 11 degrees Celsius 12 degrees Celsius 13 degrees Celsius 14 degrees Celsius 14 degrees Celsius 15 degrees Celsius
Valley
Valley 12 degrees Celsius 13 degrees Celsius 14 degrees Celsius 16 degrees Celsius 16 degrees Celsius 16 degrees Celsius
Freezing Level Freezing Level
3500m
3800m
3600m
3200m
2700m
2700m

Additional weather information

Meteorologist's view

Very wet and windy today with waterproofs essential. Gale force gusts especially on high summits will make extremely difficult walking conditions and exacerbate wind chill.

Weather

Overcast with patchy rain or drizzle at first but rain soon turning persistent and heavier from the north by mid-morning, accompanied by generally strong winds and upland gales. Rain continuing well into the afternoon, perhaps turning patchier and lighter later towards the evening. Strongest winds slowly abating.

Chance of cloud-free hill tops

20%, though nil in west from mid-morning.

Low cloud and visibility

Widespread cloud bases 400-500m, patches down to 200-300m, especially across western facing hills from mid-morning. Highest bases in the east. Moderate to poor visibility in rain, very poor in low cloud.

Ground conditions

No recent ground conditions report available.

Summit specific forecast