Mountain weather

Mountain weather

Eryri / Snowdonia

Confidence

High for overall unsettled theme, but lower for details of any precipitation.

Sunrise: Sunset:
Sunrise: Sunset:
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.

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.
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

A wet and windy start, then fresher with sunny spells.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Heavy rain showers (night) Cloudy Sunny intervals Sunny intervals Heavy rain showers Partly cloudy (night)
Chance of
precipitation
(at 800m)
Chance of precipitation
60%
30%
30%
40%
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 33mph knots
W
33mph
W 35mph knots
W
35mph
W 34mph knots
W
34mph
W 32mph knots
W
32mph
W 31mph knots
W
31mph
W 31mph knots
W
31mph
600m
600m W 22mph knots
W
22mph
W 26mph knots
W
26mph
W 26mph knots
W
26mph
W 25mph knots
W
25mph
W 20mph knots
W
20mph
W 20mph knots
W
20mph
300m
300m W 12mph knots
W
12mph
W 17mph knots
W
17mph
W 19mph knots
W
19mph
W 18mph knots
W
18mph
W 14mph knots
W
14mph
W 14mph knots
W
14mph
Valley
Valley W 12mph knots
W
12mph
W 17mph knots
W
17mph
W 19mph knots
W
19mph
W 18mph knots
W
18mph
W 14mph knots
W
14mph
W 14mph knots
W
14mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 39mph 43mph 42mph 41mph 39mph 39mph
600m
600m 27mph 32mph 34mph 33mph 27mph 27mph
300m
300m 23mph 29mph 31mph 30mph 25mph 25mph
Valley
Valley 22mph 29mph 31mph 30mph 24mph 26mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 4 degrees Celsius 2 degrees Celsius 3 degrees Celsius 4 degrees Celsius 4 degrees Celsius 3 degrees Celsius
600m
600m 8 degrees Celsius 6 degrees Celsius 7 degrees Celsius 8 degrees Celsius 8 degrees Celsius 7 degrees Celsius
300m
300m 11 degrees Celsius 10 degrees Celsius 11 degrees Celsius 12 degrees Celsius 12 degrees Celsius 11 degrees Celsius
Valley
Valley 13 degrees Celsius 12 degrees Celsius 12 degrees Celsius 13 degrees Celsius 13 degrees Celsius 12 degrees Celsius
Freezing Level Freezing Level
1800m
2000m
2000m
2000m
2100m
2100m

Additional weather information

Meteorologist's view

An improving picture through the morning with moderate UV levels in the afternoon sunshine, so sun protection may be needed. Blustery winds are expected, so that may make walking tricky at times on the summits.

Weather

A wet start with heavy rain possible at first in the morning. This should quickly clear south, with skies brightening up by mid-morning with sunny spells during the afternoon. The odd shower possible, particularly later in the afternoon. Brisk winds and feeling fresher.

Chance of cloud-free hill tops

20% rising to 80%.

Low cloud and visibility

Some low cloud likely with bases above 500-600m, with patchy areas above 300m initially. This is expected to lift above summits by late morning. Generally very good visibility, but poor in any rain or low cloud.

Ground conditions

Please see - https://yrwyddfa.live/

Summit specific forecast