Mountain weather

Mountain weather

Eryri / Snowdonia

Confidence

High for a change to cooler and fresher conditions over the weekend. Lower confidence for rain and shower detail.

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.

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.
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

Early thundery showers soon clearing to leave a dry day, with some bright or sunny spells.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Sunny Sunny intervals Fog Fog Cloudy Cloudy
Chance of
precipitation
(at 800m)
Chance of precipitation
20%
10%
10%
10%
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 S 20mph knots
S
20mph
S 18mph knots
S
18mph
S 26mph knots
S
26mph
SW 34mph knots
SW
34mph
SW 34mph knots
SW
34mph
SW 32mph knots
SW
32mph
600m
600m S 10mph knots
S
10mph
S 17mph knots
S
17mph
S 26mph knots
S
26mph
SW 27mph knots
SW
27mph
SW 25mph knots
SW
25mph
S 22mph knots
S
22mph
300m
300m S 4mph knots
S
4mph
S 13mph knots
S
13mph
S 20mph knots
S
20mph
SW 21mph knots
SW
21mph
SW 19mph knots
SW
19mph
S 16mph knots
S
16mph
Valley
Valley S 4mph knots
S
4mph
S 13mph knots
S
13mph
S 20mph knots
S
20mph
S 22mph knots
S
22mph
S 18mph knots
S
18mph
S 15mph knots
S
15mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 24mph 23mph 33mph 43mph 43mph 40mph
600m
600m 14mph 23mph 34mph 36mph 34mph 29mph
300m
300m 8mph 20mph 32mph 34mph 30mph 29mph
Valley
Valley 8mph 20mph 31mph 33mph 29mph 27mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 18 degrees Celsius 15 degrees Celsius 12 degrees Celsius 8 degrees Celsius 7 degrees Celsius 7 degrees Celsius
600m
600m 23 degrees Celsius 18 degrees Celsius 13 degrees Celsius 10 degrees Celsius 10 degrees Celsius 10 degrees Celsius
300m
300m 27 degrees Celsius 22 degrees Celsius 16 degrees Celsius 14 degrees Celsius 14 degrees Celsius 13 degrees Celsius
Valley
Valley 27 degrees Celsius 24 degrees Celsius 18 degrees Celsius 16 degrees Celsius 16 degrees Celsius 15 degrees Celsius
Freezing Level Freezing Level
3700m
3700m
3200m
3200m
3100m
2900m

Additional weather information

Meteorologist's view

Very hot and humid conditions are expected so carry plenty of water and use adequate sun protection. Stay up to date with Met Office warnings for extreme heat. The risk of thunderstorms bringing frequent lightning and strong, gusty winds, could create potentially dangerous conditions on exposed terrain.

Weather

Early thundery showers soon clearing to leave a dry and bright morning, with sunny spells. However, turning increasing cloudy into the afternoon, with low cloud shrouding the summits, especially on the western side of the Park, with sunnier skies to the north and east.

Chance of cloud-free hill tops

80%

Low cloud and visibility

A chance of cloud bases dropping to around 400-500m in western areas of the park during the afternoon. Good visibility overall, but dropping later in low cloud.

Ground conditions

Please see - https://yrwyddfa.live/

Summit specific forecast