Mountain weather

Mountain weather

Eryri / Snowdonia

Confidence

High for overall change to more unsettled conditions. Low with respect to detail of showers.

Mountain hazards

Mountain weather hazards

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

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.
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.

Mountain weather forecast

A band of rain and showers pushes north, followed by brighter skies and a continued risk of showers.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Heavy rain showers Heavy rain showers Heavy rain showers Heavy rain showers Cloudy Cloudy
Chance of
precipitation
(at 800m)
Chance of precipitation
60%
60%
40%
40%
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 SE 18mph knots
SE
18mph
SE 23mph knots
SE
23mph
SE 16mph knots
SE
16mph
SE 13mph knots
SE
13mph
E 12mph knots
E
12mph
E 16mph knots
E
16mph
600m
600m SE 14mph knots
SE
14mph
SE 14mph knots
SE
14mph
SE 11mph knots
SE
11mph
S 8mph knots
S
8mph
NE 5mph knots
NE
5mph
E 10mph knots
E
10mph
300m
300m SE 7mph knots
SE
7mph
SE 7mph knots
SE
7mph
SE 6mph knots
SE
6mph
S 6mph knots
S
6mph
SE 3mph knots
SE
3mph
E 7mph knots
E
7mph
Valley
Valley SE 7mph knots
SE
7mph
SE 7mph knots
SE
7mph
SE 6mph knots
SE
6mph
S 6mph knots
S
6mph
S 4mph knots
S
4mph
SE 6mph knots
SE
6mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 22mph 27mph 20mph 17mph 15mph 21mph
600m
600m 22mph 19mph 15mph 11mph 9mph 16mph
300m
300m 15mph 14mph 13mph 10mph 7mph 15mph
Valley
Valley 15mph 14mph 13mph 9mph 8mph 13mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 8 degrees Celsius 8 degrees Celsius 11 degrees Celsius 13 degrees Celsius 13 degrees Celsius 10 degrees Celsius
600m
600m 11 degrees Celsius 12 degrees Celsius 14 degrees Celsius 16 degrees Celsius 16 degrees Celsius 14 degrees Celsius
300m
300m 14 degrees Celsius 15 degrees Celsius 18 degrees Celsius 19 degrees Celsius 19 degrees Celsius 16 degrees Celsius
Valley
Valley 15 degrees Celsius 17 degrees Celsius 19 degrees Celsius 21 degrees Celsius 20 degrees Celsius 18 degrees Celsius
Freezing Level Freezing Level
3200m
3100m
3100m
3100m
2900m
2900m

Additional weather information

Meteorologist's view

A showery day across the park with the risk some heavier bursts means that adequate waterproofs are necessary. UV levels remaining high in sunny spells between showers so sun protection advisable.

Weather

A cloudier start to the day with showers, potentially heavy and thundery at times spreading in from the south through the morning. Likely turning drier and brighter through the afternoon as the cloud. A low risk of the odd isolated shower remains, these again have the potential to be heavy and thundery at times.

Chance of cloud-free hill tops

20% gradually rising to 90% through the morning.

Low cloud and visibility

Cloud bases initially above summits but widespread lower cloud is then expected to spread in from the southwest around dawn, with bases above 400-500m. Through the afternoon low cloud is expected to clear leaving all bases above summits. Very good views are expected but visibilities may become poor or very poor in patchy low cloud through the morning. Visibilities may also drop to moderate or potentially poor in passing showers.

Ground conditions

Please see - https://yrwyddfa.live/

Summit specific forecast