Mountain weather

Mountain weather

Eryri / Snowdonia

Confidence

High for an increasingly settled and rather warm weekend. Moderate regarding how long the mostly fine weather will last next week.

Mountain hazards

Mountain weather hazards

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

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.
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.

Mountain weather forecast

A damp and murky start, brightening up with some afternoon sunny spells. Windy.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Light rain Fog Cloudy Sunny intervals Sunny intervals Cloudy
Chance of
precipitation
(at 800m)
Chance of precipitation
≥95%
70%
40%
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 W 33mph knots
W
33mph
W 38mph knots
W
38mph
W 35mph knots
W
35mph
W 36mph knots
W
36mph
W 31mph knots
W
31mph
W 34mph knots
W
34mph
600m
600m SW 23mph knots
SW
23mph
W 27mph knots
W
27mph
W 27mph knots
W
27mph
W 27mph knots
W
27mph
W 21mph knots
W
21mph
W 20mph knots
W
20mph
300m
300m SW 14mph knots
SW
14mph
W 18mph knots
W
18mph
W 19mph knots
W
19mph
W 20mph knots
W
20mph
W 14mph knots
W
14mph
W 13mph knots
W
13mph
Valley
Valley SW 14mph knots
SW
14mph
W 18mph knots
W
18mph
W 19mph knots
W
19mph
W 20mph knots
W
20mph
W 14mph knots
W
14mph
W 13mph knots
W
13mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 38mph 46mph 44mph 46mph 39mph 42mph
600m
600m 28mph 34mph 36mph 36mph 29mph 28mph
300m
300m 24mph 29mph 32mph 33mph 24mph 26mph
Valley
Valley 24mph 28mph 32mph 33mph 24mph 26mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 5 degrees Celsius 5 degrees Celsius 5 degrees Celsius 5 degrees Celsius 4 degrees Celsius 1 degrees Celsius
600m
600m 8 degrees Celsius 8 degrees Celsius 8 degrees Celsius 8 degrees Celsius 8 degrees Celsius 6 degrees Celsius
300m
300m 10 degrees Celsius 10 degrees Celsius 12 degrees Celsius 12 degrees Celsius 12 degrees Celsius 9 degrees Celsius
Valley
Valley 12 degrees Celsius 12 degrees Celsius 13 degrees Celsius 13 degrees Celsius 13 degrees Celsius 11 degrees Celsius
Freezing Level Freezing Level
3000m
2300m
1900m
1800m
1800m
1800m

Additional weather information

Meteorologist's view

Fog and very poor visibility will make for significant navigational challenges on higher routes through the morning, though this will improve into the afternoon. High or very high UV levels developing once the sun comes out, so take precautions by using sunscreen. Strong buffeting by winds on ridges and summits will make for arduous walking conditions at height today.

Weather

A cloudy start with widespread mist and fog on higher ground. Occasional rain and drizzle during the morning, this most persistent in western areas, before turning mostly dry through the afternoon. Cloud breaking up later in the day with sunny spells becoming more extensive from the north during the afternoon. Windy throughout, with gale-force gusts likely at higher elevations.

Chance of cloud-free hill tops

10%, increasing to 80% in north by mid-afternoon and 60% in south by late-afternoon.

Low cloud and visibility

Widespread cloud above 150-300m at first, lifting to 400-600m by late morning and then rising to patches above 700-800m through the afternoon. Slowest to lift and break in the south. Very poor visibility in cloud but good or very good visibility at lower levels outside of any rain or drizzle. Becoming widely very good visibility later in the day.

Ground conditions

Please see - https://yrwyddfa.live/

Summit specific forecast