Mountain weather

Mountain weather

Eryri / Snowdonia

Confidence

High overall, lower for details later in the week.

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

Mostly dry, partly cloudy with sunny intervals.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Sunny intervals Cloudy Cloudy Sunny intervals Cloudy Light rain
Chance of
precipitation
(at 800m)
Chance of precipitation
10%
10%
10%
10%
20%
30%

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 21mph knots
W
21mph
W 19mph knots
W
19mph
SW 17mph knots
SW
17mph
SW 20mph knots
SW
20mph
SW 19mph knots
SW
19mph
SW 21mph knots
SW
21mph
600m
600m SW 16mph knots
SW
16mph
W 14mph knots
W
14mph
SW 14mph knots
SW
14mph
SW 18mph knots
SW
18mph
SW 18mph knots
SW
18mph
S 16mph knots
S
16mph
300m
300m W 9mph knots
W
9mph
W 10mph knots
W
10mph
SW 9mph knots
SW
9mph
SW 12mph knots
SW
12mph
SW 12mph knots
SW
12mph
S 9mph knots
S
9mph
Valley
Valley W 9mph knots
W
9mph
W 10mph knots
W
10mph
SW 9mph knots
SW
9mph
SW 12mph knots
SW
12mph
SW 12mph knots
SW
12mph
S 9mph knots
S
9mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 26mph 22mph 21mph 24mph 23mph 24mph
600m
600m 19mph 17mph 17mph 22mph 23mph 20mph
300m
300m 16mph 15mph 15mph 19mph 19mph 17mph
Valley
Valley 15mph 15mph 14mph 19mph 19mph 17mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 2 degrees Celsius 3 degrees Celsius 5 degrees Celsius 6 degrees Celsius 5 degrees Celsius 4 degrees Celsius
600m
600m 6 degrees Celsius 7 degrees Celsius 8 degrees Celsius 9 degrees Celsius 8 degrees Celsius 8 degrees Celsius
300m
300m 10 degrees Celsius 11 degrees Celsius 12 degrees Celsius 13 degrees Celsius 12 degrees Celsius 12 degrees Celsius
Valley
Valley 12 degrees Celsius 13 degrees Celsius 14 degrees Celsius 14 degrees Celsius 14 degrees Celsius 13 degrees Celsius
Freezing Level Freezing Level
2200m
2300m
2300m
2300m
2300m
2300m

Additional weather information

Meteorologist's view

Despite the mostly cloudy conditions, strong sunshine in any clear spells through the afternoon, sun protection advised. Cloud covering peaks at times leading to low visibility.

Weather

Variable amounts of cloud across the park, with clear or sunny intervals early and then through the early afternoon. High cloud building through the afternoon with overcast skies developing during the evening. An increasing chance of light rain into the evening and overnight.

Chance of cloud-free hill tops

70%

Low cloud and visibility

Cloud may cover the highest summits early and late, with bases around 900m, otherwise above summits. Visibility generally good to very good, but deteriorating to moderate in any rain later.

Ground conditions

Please see - https://yrwyddfa.live/

Summit specific forecast