Mountain weather

Mountain weather

Eryri / Snowdonia

Confidence

High for generally settled conditions persisting for much of the period. Confidence drops at the end of the outlook as low pressure may encroach from the south. Low to moderate for extent of low cloud on Friday and valley fog over the weekend.

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.

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

Extensive hill fog and reasonably light winds. Improving towards evening somewhat.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Light rain Light rain Light rain Cloudy Partly cloudy (night) Partly cloudy (night)
Chance of
precipitation
(at 800m)
Chance of precipitation
80%
60%
50%
20%
10%
10%

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 23mph knots
E
23mph
E 17mph knots
E
17mph
E 13mph knots
E
13mph
E 8mph knots
E
8mph
E 6mph knots
E
6mph
E 5mph knots
E
5mph
600m
600m E 10mph knots
E
10mph
SE 7mph knots
SE
7mph
E 7mph knots
E
7mph
SE 6mph knots
SE
6mph
SE 3mph knots
SE
3mph
SE 4mph knots
SE
4mph
300m
300m SE 5mph knots
SE
5mph
SE 4mph knots
SE
4mph
NE 5mph knots
NE
5mph
SE 4mph knots
SE
4mph
SE 2mph knots
SE
2mph
SE 4mph knots
SE
4mph
Valley
Valley SE 5mph knots
SE
5mph
SE 3mph knots
SE
3mph
NE 5mph knots
NE
5mph
SE 4mph knots
SE
4mph
SE 2mph knots
SE
2mph
SE 4mph knots
SE
4mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 31mph 22mph 17mph 10mph 8mph 7mph
600m
600m 19mph 12mph 11mph 9mph 5mph 6mph
300m
300m 14mph 8mph 8mph 8mph 6mph 6mph
Valley
Valley 14mph 7mph 8mph 8mph 6mph 6mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m -5 degrees Celsius -4 degrees Celsius -2 degrees Celsius 0 degrees Celsius 0 degrees Celsius 0 degrees Celsius
600m
600m 1 degrees Celsius 2 degrees Celsius 2 degrees Celsius 4 degrees Celsius 4 degrees Celsius 4 degrees Celsius
300m
300m 5 degrees Celsius 6 degrees Celsius 6 degrees Celsius 7 degrees Celsius 7 degrees Celsius 6 degrees Celsius
Valley
Valley 7 degrees Celsius 7 degrees Celsius 8 degrees Celsius 9 degrees Celsius 8 degrees Celsius 7 degrees Celsius
Freezing Level Freezing Level
1600m
1600m
1600m
1600m
1500m
1400m

Additional weather information

Meteorologist's view

A fresh southeasterly breeze through the morning, easing considerably in the afternoon. Widespread hill fog will make route finding difficult at times so care needs to be taken while navigating.

Weather

A cloudy start with outbreaks of light to moderate rain or drizzle. Turning dry from the south from mid-afternoon onwards as the cloud starts to break up. Fog patches possible in valleys overnight.

Chance of cloud-free hill tops

20% increasing to 70% in the evening.

Low cloud and visibility

Extensive hill fog above 500m (possibly as low as 350m in the southeast of the area) in the morning. Cloud bases gradually lifting to 600-700m in the afternoon and to 1000m in the evening with some breaks expected. Away from low cloud, visibility generally good but dropping to 3000-6000m in rain. Poor in valley fog overnight.

Ground conditions

No recent ground conditions report available.

Summit specific forecast