Mountain weather

Mountain weather

Eryri / Snowdonia

Confidence

Generally high confidence.

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.
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.

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

Morning showers, followed by a drier afternoon, before rain returns.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Heavy rain showers Light rain showers Light rain showers Cloudy Light rain Heavy Rain
Chance of
precipitation
(at 800m)
Chance of precipitation
60%
40%
30%
20%
40%
80%

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 SW 13mph knots
SW
13mph
SW 11mph knots
SW
11mph
SW 12mph knots
SW
12mph
SW 14mph knots
SW
14mph
S 17mph knots
S
17mph
S 22mph knots
S
22mph
600m
600m SW 8mph knots
SW
8mph
SW 10mph knots
SW
10mph
SW 12mph knots
SW
12mph
SW 13mph knots
SW
13mph
S 14mph knots
S
14mph
S 17mph knots
S
17mph
300m
300m W 5mph knots
W
5mph
W 7mph knots
W
7mph
SW 9mph knots
SW
9mph
SW 10mph knots
SW
10mph
S 11mph knots
S
11mph
S 11mph knots
S
11mph
Valley
Valley W 5mph knots
W
5mph
W 7mph knots
W
7mph
SW 7mph knots
SW
7mph
SW 7mph knots
SW
7mph
S 10mph knots
S
10mph
S 11mph knots
S
11mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 16mph 17mph 20mph 21mph 24mph 30mph
600m
600m 11mph 15mph 19mph 20mph 21mph 25mph
300m
300m 9mph 14mph 17mph 18mph 19mph 22mph
Valley
Valley 9mph 12mph 13mph 13mph 17mph 21mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m -2 degrees Celsius -2 degrees Celsius 0 degrees Celsius 1 degrees Celsius -1 degrees Celsius -1 degrees Celsius
600m
600m 1 degrees Celsius 2 degrees Celsius 3 degrees Celsius 4 degrees Celsius 2 degrees Celsius 2 degrees Celsius
300m
300m 5 degrees Celsius 6 degrees Celsius 7 degrees Celsius 8 degrees Celsius 6 degrees Celsius 6 degrees Celsius
Valley
Valley 6 degrees Celsius 8 degrees Celsius 9 degrees Celsius 10 degrees Celsius 9 degrees Celsius 8 degrees Celsius
Freezing Level Freezing Level
1100m
1100m
1200m
1200m
1600m
1700m

Additional weather information

Meteorologist's view

Appropriate footwear for damp ground necessary due to recent rain. UV levels moderate during the day with sun protection advised.

Weather

A band of heavy, organised showers clearing eastwards during the early morning. Mostly dry thereafter with a low risk of a few showers into the afternoon. More persistent rain edging in by the evening and moving across the park into the night, heavy in the west. Winds increasing.

Chance of cloud-free hill tops

60% dropping to 40% by end of day.

Low cloud and visibility

Broken cloud around 400-500 m at first, lifting mostly above summits, then lowering further by the evening down to 400m and becoming more widespread across the park. Good visibility outside showers, dropping to very poor by the evening in more persistent rain.

Ground conditions

Please see - https://yrwyddfa.live/

Summit specific forecast