Mountain weather

Mountain weather

Eryri / Snowdonia

Confidence

High though some uncertainty on amount of cloud.

Mountain hazards

Mountain weather hazards

Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.

Strong Sunlight
Harmful UV levels from sunlight increase with altitude giving a greater risk of sunburn and eye damage, even on some overcast days. On breezy days, the cooling effect of wind on exposed skin may disguise any feeling of sunburn until it is too late. If there is snow cover, glare increases the effect of UV rays especially on the eyes. It is advisable to wear sun block, protective clothing such as a long-sleeved top and hat and have good quality eye protection.

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.
Thunderstorms
Lightning is a significant mountain hazard which can result in serious injury or death. Mountain terrain often leaves one highly exposed to lightning strikes. Hail may give unpleasant conditions with torrential rain and localised flash flooding also possible, mainly in Summer months.

Mountain weather forecast

Cloudy start but mostly dry with isolated showers. Staying hot and humid.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Fog Cloudy Sunny intervals Sunny intervals Sunny intervals Heavy rain showers (night)
Chance of
precipitation
(at 800m)
Chance of precipitation
20%
10%
10%
10%
10%
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 S 33mph knots
S
33mph
S 38mph knots
S
38mph
S 39mph knots
S
39mph
SW 40mph knots
SW
40mph
SW 37mph knots
SW
37mph
S 33mph knots
S
33mph
600m
600m S 22mph knots
S
22mph
S 27mph knots
S
27mph
S 30mph knots
S
30mph
S 29mph knots
S
29mph
S 25mph knots
S
25mph
S 24mph knots
S
24mph
300m
300m S 14mph knots
S
14mph
S 18mph knots
S
18mph
S 21mph knots
S
21mph
S 19mph knots
S
19mph
S 16mph knots
S
16mph
S 15mph knots
S
15mph
Valley
Valley S 14mph knots
S
14mph
S 18mph knots
S
18mph
S 21mph knots
S
21mph
S 19mph knots
S
19mph
S 15mph knots
S
15mph
S 14mph knots
S
14mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 39mph 45mph 49mph 51mph 46mph 42mph
600m
600m 27mph 34mph 40mph 39mph 33mph 32mph
300m
300m 24mph 30mph 36mph 34mph 28mph 27mph
Valley
Valley 24mph 30mph 35mph 33mph 28mph 26mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 7 degrees Celsius 7 degrees Celsius 8 degrees Celsius 7 degrees Celsius 7 degrees Celsius 8 degrees Celsius
600m
600m 11 degrees Celsius 10 degrees Celsius 10 degrees Celsius 11 degrees Celsius 11 degrees Celsius 10 degrees Celsius
300m
300m 14 degrees Celsius 14 degrees Celsius 14 degrees Celsius 15 degrees Celsius 15 degrees Celsius 14 degrees Celsius
Valley
Valley 16 degrees Celsius 16 degrees Celsius 16 degrees Celsius 17 degrees Celsius 17 degrees Celsius 16 degrees Celsius
Freezing Level Freezing Level
2800m
2500m
3100m
3100m
3100m
3100m

Additional weather information

Meteorologist's view

Another hot and humid day expected with very high UV levels. Plenty of sun protection is needed and stay hydrated and carry extra bottles of water. Wear light clothes with hats and glasses, to protect from the sun.

Weather

A mostly dry and bright day ahead, especially in the afternoon. Patchy light rain around. Otherwise sunny spells, and a chance of some patchy lower cloud pushing in from the west into the late afternoon. Evening showers look likely, some of which may be heavy at times or even thundery.

Chance of cloud-free hill tops

40% rising to 80% in the afternoon.

Low cloud and visibility

Some mist and fog possible to start of the day and moderate or poor in any evening showers, otherwise very good visibility. Little cloud during the day, though bases may drop to around 700-800m from the west during the late evening. Potentially around to 200-300m by towards midnight.

Ground conditions

Please see - https://yrwyddfa.live/

Summit specific forecast