Mountain weather

Mountain weather

Eryri / Snowdonia

Confidence

High confidence for a changeable theme. Lower for the clearance of low cloud and rain tomorrow morning and arrival tomorrow night.

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.

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.

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.

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.

Mountain weather forecast

Damp and dull start. Brighter by the afternoon, with heavy rain arriving later. Windy.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Fog Fog Fog Sunny intervals Sunny intervals Light rain
Chance of
precipitation
(at 800m)
Chance of precipitation
80%
80%
50%
20%
20%
70%

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 E 42mph knots
E
42mph
SE 47mph knots
SE
47mph
SE 45mph knots
SE
45mph
SE 43mph knots
SE
43mph
SE 45mph knots
SE
45mph
SE 45mph knots
SE
45mph
600m
600m SE 23mph knots
SE
23mph
SE 29mph knots
SE
29mph
SE 31mph knots
SE
31mph
SE 29mph knots
SE
29mph
SE 31mph knots
SE
31mph
SE 31mph knots
SE
31mph
300m
300m SE 15mph knots
SE
15mph
SE 21mph knots
SE
21mph
SE 23mph knots
SE
23mph
SE 21mph knots
SE
21mph
SE 20mph knots
SE
20mph
SE 20mph knots
SE
20mph
Valley
Valley SE 14mph knots
SE
14mph
SE 20mph knots
SE
20mph
SE 23mph knots
SE
23mph
SE 21mph knots
SE
21mph
SE 20mph knots
SE
20mph
SE 20mph knots
SE
20mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 47mph 54mph 54mph 52mph 54mph 55mph
600m
600m 30mph 36mph 40mph 38mph 40mph 40mph
300m
300m 29mph 36mph 39mph 36mph 37mph 37mph
Valley
Valley 29mph 36mph 38mph 36mph 37mph 37mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 2 degrees Celsius 4 degrees Celsius 6 degrees Celsius 8 degrees Celsius 8 degrees Celsius 7 degrees Celsius
600m
600m 6 degrees Celsius 7 degrees Celsius 9 degrees Celsius 11 degrees Celsius 11 degrees Celsius 10 degrees Celsius
300m
300m 9 degrees Celsius 10 degrees Celsius 12 degrees Celsius 15 degrees Celsius 15 degrees Celsius 15 degrees Celsius
Valley
Valley 10 degrees Celsius 12 degrees Celsius 14 degrees Celsius 17 degrees Celsius 17 degrees Celsius 16 degrees Celsius
Freezing Level Freezing Level
2200m
2900m
3100m
3200m
3200m
3200m

Additional weather information

Meteorologist's view

Good navigational skills required in low cloud and poor visibilities. Conditions improving later with moderate UV levels however strong to gale force winds will likely make moving across exposed terrain difficult with strong buffeting near summits.

Weather

Low cloud bringing a risk of hill fog, light rain and drizzle through the morning. This is expected to lift and break into the afternoon with a band of heavy and persistent rain, arriving from the west, overnight. Turning unsettled and windy with strong southeasterly winds developing and a chance of summit gales.

Chance of cloud-free hill tops

10% rising to over 60% by mid-afternoon.

Low cloud and visibility

Cloud bases initially 300-400m, possibly as low as 200m in places, rising to 500-600m by the afternoon, before gradually rising above summits. Poor or very poor visibilities in hill fog and drizzle, otherwise moderate visibilities in light rain. Good views of distant hills by the afternoon once the rain and cloud clears. Low cloud and hill fog, as well as a deterioration in visibilities can be expected overnight when another band of rain arrives.

Ground conditions

No recent ground conditions report available.

Summit specific forecast