Mountain weather

Mountain weather

Eryri / Snowdonia

Confidence

High for overall set up with mostly fine weather in coming days. Lower for cloud amounts and rainfall amounts Wednesday night into Thursday.

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.
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.
Heavy Persistent Rain
Heavy and persistent rain can lead to drenched clothing and footwear with waterproofs often becoming soaked through, especially if accompanied by strong winds. This can lead to significant loss of body heat and an increased likelihood of hypothermia. Terrain may turn increasingly boggy underfoot while streams can flood and become impassable. There may also be a risk of flooding in valleys or glens. If there is snow cover, a heightened avalanche hazard is possible and avalanche reports should be consulted where available.

Mountain weather forecast

Low cloud with summit fog lifting in morning. Evening rain.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Light rain Fog Fog Mist Cloudy Heavy Rain
Chance of
precipitation
(at 800m)
Chance of precipitation
60%
30%
10%
10%
40%
≥95%

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 NW 15mph knots
NW
15mph
W 13mph knots
W
13mph
W 14mph knots
W
14mph
SW 22mph knots
SW
22mph
SW 36mph knots
SW
36mph
SW 40mph knots
SW
40mph
600m
600m NW 11mph knots
NW
11mph
W 10mph knots
W
10mph
W 12mph knots
W
12mph
SW 20mph knots
SW
20mph
S 27mph knots
S
27mph
SW 28mph knots
SW
28mph
300m
300m NW 8mph knots
NW
8mph
W 7mph knots
W
7mph
W 9mph knots
W
9mph
SW 14mph knots
SW
14mph
S 19mph knots
S
19mph
SW 19mph knots
SW
19mph
Valley
Valley NW 8mph knots
NW
8mph
W 7mph knots
W
7mph
W 9mph knots
W
9mph
SW 13mph knots
SW
13mph
S 19mph knots
S
19mph
SW 19mph knots
SW
19mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 17mph 17mph 19mph 29mph 44mph 50mph
600m
600m 13mph 12mph 16mph 26mph 35mph 37mph
300m
300m 11mph 10mph 13mph 22mph 32mph 33mph
Valley
Valley 11mph 10mph 13mph 22mph 31mph 33mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 7 degrees Celsius 6 degrees Celsius 7 degrees Celsius 6 degrees Celsius 3 degrees Celsius 5 degrees Celsius
600m
600m 10 degrees Celsius 10 degrees Celsius 9 degrees Celsius 9 degrees Celsius 6 degrees Celsius 8 degrees Celsius
300m
300m 12 degrees Celsius 13 degrees Celsius 12 degrees Celsius 13 degrees Celsius 10 degrees Celsius 10 degrees Celsius
Valley
Valley 13 degrees Celsius 14 degrees Celsius 14 degrees Celsius 14 degrees Celsius 12 degrees Celsius 12 degrees Celsius
Freezing Level Freezing Level
2500m
2400m
2000m
3500m
3500m
3700m

Additional weather information

Meteorologist's view

Poor visibility initially and by the end of the day. Otherwise, high UV levels with sunscreen advised.

Weather

A misty start with cloud covering summits and the odd shower. Cloud breaking and lifting, with some sunnier spells through the afternoon across eastern areas of the Park. Becoming cloudier into the evening with rain arriving by late evening. Winds increasing quickly as rain arrives.

Chance of cloud-free hill tops

30% increasing 80% into the afternoon, especially in eastern parts. Dropping back to 40% by evening.

Low cloud and visibility

Areas broken to overcast cloud around 400 m. This breaking and lifting to mostly above summits by the afternoon. Visibility poor or very poor in summit cloud otherwise good or very good. Falling moderate to poor in heavy rain later.

Ground conditions

Please see - https://yrwyddfa.live/

Summit specific forecast