Mountain weather

Mountain weather

Eryri / Snowdonia

Confidence

High for very unsettled Autumnal conditions at first becoming more settled during the week. Medium for cloud details.

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.

Storm Force Winds
Storm force winds (gusts over 70mph) make walking very strenuous with any mobility virtually impossible over exposed ground. Where these conditions occur there is a high risk of being blown over and even standing may be impossible at times with a risk of being blown off one’s feet. Basic tasks such as using a map, eating, putting on extra clothing or communication become extremely difficult away from any shelter.
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 becoming very windy, with storm force winds developing later in the day on higher slopes.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Fog Heavy Rain Heavy Rain Heavy Rain Heavy Rain Heavy Rain
Chance of
precipitation
(at 800m)
Chance of precipitation
90%
≥95%
70%
50%
30%
30%

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 S 45mph knots
S
45mph
S 45mph knots
S
45mph
SW 47mph knots
SW
47mph
SW 53mph knots
SW
53mph
SW 54mph knots
SW
54mph
S 56mph knots
S
56mph
600m
600m S 29mph knots
S
29mph
S 27mph knots
S
27mph
SW 31mph knots
SW
31mph
SW 36mph knots
SW
36mph
SW 37mph knots
SW
37mph
S 41mph knots
S
41mph
300m
300m S 18mph knots
S
18mph
SE 18mph knots
SE
18mph
SW 18mph knots
SW
18mph
SW 23mph knots
SW
23mph
S 23mph knots
S
23mph
S 26mph knots
S
26mph
Valley
Valley S 18mph knots
S
18mph
SE 19mph knots
SE
19mph
S 18mph knots
S
18mph
SW 23mph knots
SW
23mph
S 23mph knots
S
23mph
S 25mph knots
S
25mph

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 58mph 66mph 67mph 71mph
600m
600m 37mph 35mph 40mph 47mph 49mph 55mph
300m
300m 33mph 32mph 35mph 41mph 43mph 47mph
Valley
Valley 33mph 33mph 34mph 42mph 42mph 45mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m -3 degrees Celsius 0 degrees Celsius 5 degrees Celsius 4 degrees Celsius 4 degrees Celsius 4 degrees Celsius
600m
600m 0 degrees Celsius 3 degrees Celsius 7 degrees Celsius 6 degrees Celsius 6 degrees Celsius 6 degrees Celsius
300m
300m 4 degrees Celsius 7 degrees Celsius 10 degrees Celsius 10 degrees Celsius 10 degrees Celsius 10 degrees Celsius
Valley
Valley 6 degrees Celsius 8 degrees Celsius 11 degrees Celsius 11 degrees Celsius 11 degrees Celsius 11 degrees Celsius
Freezing Level Freezing Level
2600m
3300m
3200m
2300m
2400m
2600m

Additional weather information

Meteorologist's view

A wet day with waterproofs becoming soaked and challenging navigation conditions. Turning very windy, making for extremely difficult walking later with a risk of being blown off your feet, especially on higher slopes and exposed ridges and summits.

Weather

Extensive cloud and outbreaks of rain, this heavy and persistent during the morning. Rain easing somewhat during the afternoon, but low cloud lingering with outbreaks of light rain or drizzle. Winds strengthening, with gales developing widely and storm force gusts expected later in the day on higher slopes, especially in the north.

Chance of cloud-free hill tops

20% during the morning, becoming 40% during the afternoon.

Low cloud and visibility

Widespread low cloud with base 300 to 500m, perhaps with some lower patches, during the morning. Lifting a little during the afternoon but staying widespread, base 400-600m. Visibility mostly moderate to very poor in rain and low cloud covering the hills, perhaps occasionally good later below cloud and away from rain.

Ground conditions

No recent ground conditions report available.

Summit specific forecast