Mountain weather

Mountain weather

Eryri / Snowdonia

Confidence

High for conditions through Wednesday morning and an improvement through the late afternoon. Lower confidence in extent of cloud across low levels in the mid-afternoon. High confidence in settled conditions persisting through the forecast period but low confidence in details of rainfall on Saturday and fog extent on Sunday.

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.

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.

Mountain weather forecast

Initially cloudy with occasional outbreaks of drizzle and a risk of hill fog. Cloud bases rising through the day then dissipating in the evening allowing some clear spells to develop.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Drizzle Drizzle Cloudy Light rain showers Partly cloudy (night) Partly cloudy (night)
Chance of
precipitation
(at 800m)
Chance of precipitation
60%
40%
20%
30%
20%
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 33mph knots
E
33mph
E 36mph knots
E
36mph
E 34mph knots
E
34mph
E 31mph knots
E
31mph
E 36mph knots
E
36mph
E 43mph knots
E
43mph
600m
600m NE 15mph knots
NE
15mph
E 18mph knots
E
18mph
E 19mph knots
E
19mph
NE 16mph knots
NE
16mph
NE 16mph knots
NE
16mph
E 22mph knots
E
22mph
300m
300m NE 6mph knots
NE
6mph
E 7mph knots
E
7mph
E 9mph knots
E
9mph
NE 8mph knots
NE
8mph
NE 7mph knots
NE
7mph
E 10mph knots
E
10mph
Valley
Valley NE 6mph knots
NE
6mph
E 6mph knots
E
6mph
E 8mph knots
E
8mph
NE 7mph knots
NE
7mph
NE 6mph knots
NE
6mph
E 9mph knots
E
9mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 38mph 42mph 41mph 38mph 43mph 52mph
600m
600m 20mph 23mph 25mph 22mph 23mph 32mph
300m
300m 16mph 16mph 20mph 17mph 17mph 24mph
Valley
Valley 15mph 15mph 19mph 16mph 16mph 22mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m -4 degrees Celsius -4 degrees Celsius -4 degrees Celsius -3 degrees Celsius -4 degrees Celsius -6 degrees Celsius
600m
600m 0 degrees Celsius 0 degrees Celsius 1 degrees Celsius 2 degrees Celsius 1 degrees Celsius -1 degrees Celsius
300m
300m 5 degrees Celsius 6 degrees Celsius 7 degrees Celsius 7 degrees Celsius 6 degrees Celsius 4 degrees Celsius
Valley
Valley 7 degrees Celsius 7 degrees Celsius 9 degrees Celsius 9 degrees Celsius 8 degrees Celsius 6 degrees Celsius
Freezing Level Freezing Level
1500m
1300m
1300m
1400m
1300m
1100m

Additional weather information

Meteorologist's view

Generally windy conditions through the period although potential for some sheltering across western valleys. Gusts approach near gales at times across summits. This, with the addition of cool air temperatures, could lead to unpleasant conditions for those walking at height. Warm clothes are advisable.

Weather

Widespread cloud spreads across the area with bases low enough to allow hill fog in places. This accompanied with outbreaks of drizzle across eastern slopes. Cloud bases rise and briefly clear across low levels through the morning. Becoming cloudy through the afternoon with a small risk of further showery outbreaks of drizzle. Cloud then dissipating through the evening allowing clear spells to develop.

Chance of cloud-free hill tops

60% in the morning rising to 80% in the afternoon.

Low cloud and visibility

Widespread low cloud with bases at approximately 500m through the early morning. Cloud bases then rising through the morning to approximately 800m before dissipating through the evening. Below cloud generally good visibility conditions are to be expected. In low cloud and drizzle, poor visibilities at times.

Ground conditions

No recent ground conditions report available.

Summit specific forecast