Mountain weather

Mountain weather

Eryri / Snowdonia

Confidence

High for over unsettled nature of the weather, but lower for rate and intensity of showers.

Mountain hazards

Mountain weather hazards

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

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.
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

Sunny spells with showers by the afternoon.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Partly cloudy (night) Light rain showers Light rain showers Thundery showers Heavy rain showers Heavy rain showers
Chance of
precipitation
(at 800m)
Chance of precipitation
10%
40%
40%
50%
60%
60%

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 20mph knots
W
20mph
SW 23mph knots
SW
23mph
SW 29mph knots
SW
29mph
SW 23mph knots
SW
23mph
SW 22mph knots
SW
22mph
600m
600m W 13mph knots
W
13mph
W 16mph knots
W
16mph
SW 18mph knots
SW
18mph
SW 22mph knots
SW
22mph
SW 18mph knots
SW
18mph
SW 15mph knots
SW
15mph
300m
300m W 8mph knots
W
8mph
W 11mph knots
W
11mph
SW 13mph knots
SW
13mph
SW 14mph knots
SW
14mph
SW 13mph knots
SW
13mph
SW 10mph knots
SW
10mph
Valley
Valley W 8mph knots
W
8mph
W 11mph knots
W
11mph
SW 13mph knots
SW
13mph
SW 14mph knots
SW
14mph
SW 12mph knots
SW
12mph
SW 9mph knots
SW
9mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 25mph 25mph 30mph 37mph 30mph 28mph
600m
600m 16mph 21mph 24mph 29mph 24mph 20mph
300m
300m 15mph 18mph 22mph 25mph 21mph 18mph
Valley
Valley 15mph 18mph 21mph 24mph 20mph 18mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m -5 degrees Celsius -4 degrees Celsius -3 degrees Celsius -4 degrees Celsius -4 degrees Celsius -4 degrees Celsius
600m
600m -1 degrees Celsius -1 degrees Celsius 1 degrees Celsius 0 degrees Celsius 0 degrees Celsius 0 degrees Celsius
300m
300m 3 degrees Celsius 4 degrees Celsius 6 degrees Celsius 4 degrees Celsius 4 degrees Celsius 4 degrees Celsius
Valley
Valley 5 degrees Celsius 6 degrees Celsius 8 degrees Celsius 6 degrees Celsius 7 degrees Celsius 6 degrees Celsius
Freezing Level Freezing Level
1100m
1000m
1100m
1300m
1200m
1200m

Additional weather information

Meteorologist's view

Damp underfoot given recent rainfall, with rain jackets advised due to the risk of heavy showers. UV levels moderate with sun protection needed.

Weather

Generally cloudy especially in the south and west with only limited cloud breaks, and isolated showers until mid-afternoon. Then showers become more widespread and sometimes heavy, with a small chance of thunder. Showers becoming more organised from late evening and into the night with heavy downpours.

Chance of cloud-free hill tops

50% rising to 70%.

Low cloud and visibility

Patchy low cloud covering summits with heavy showers, bases around 500-700m and to start the morning. Visibility generally very good with distance hills visible, but dropping to poor in low cloud and showers.

Ground conditions

Please see - https://yrwyddfa.live/

Summit specific forecast