Mountain weather

Mountain weather

Eryri / Snowdonia

Confidence

High confidence in the overall weather but precise shower detail and timing remains lower confidence.

Mountain hazards

Mountain weather hazards

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

Severe Chill Effect
Wind significantly lowers the ‘feels-like’ temperature relative to the actual temperature, with even moderate winds significantly adding to the chilling effect. Strong winds can result in a severe and debilitating wind chill many degrees below the actual temperature. This effect will be enhanced in rain or wet snow. Without protection, prolonged exposure could result in frost nip or frostbite on exposed parts of the body and/or hypothermia.
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.

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.
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

Another day of blustery heavy 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 Heavy rain showers Light rain showers (night)
Chance of
precipitation
(at 800m)
Chance of precipitation
70%
70%
70%
70%
60%
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 NW 27mph knots
NW
27mph
N 26mph knots
N
26mph
NW 26mph knots
NW
26mph
N 26mph knots
N
26mph
N 28mph knots
N
28mph
N 25mph knots
N
25mph
600m
600m NW 19mph knots
NW
19mph
N 19mph knots
N
19mph
N 18mph knots
N
18mph
N 20mph knots
N
20mph
N 19mph knots
N
19mph
N 16mph knots
N
16mph
300m
300m NW 13mph knots
NW
13mph
N 13mph knots
N
13mph
N 13mph knots
N
13mph
N 15mph knots
N
15mph
N 14mph knots
N
14mph
N 10mph knots
N
10mph
Valley
Valley NW 13mph knots
NW
13mph
N 13mph knots
N
13mph
N 13mph knots
N
13mph
N 15mph knots
N
15mph
N 14mph knots
N
14mph
N 10mph knots
N
10mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 31mph 31mph 32mph 34mph 35mph 31mph
600m
600m 23mph 24mph 25mph 27mph 25mph 22mph
300m
300m 21mph 22mph 22mph 25mph 24mph 20mph
Valley
Valley 21mph 22mph 22mph 25mph 24mph 19mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m -6 degrees Celsius -6 degrees Celsius -6 degrees Celsius -4 degrees Celsius -5 degrees Celsius -5 degrees Celsius
600m
600m -2 degrees Celsius -2 degrees Celsius -2 degrees Celsius 0 degrees Celsius 0 degrees Celsius 0 degrees Celsius
300m
300m 1 degrees Celsius 3 degrees Celsius 2 degrees Celsius 4 degrees Celsius 4 degrees Celsius 4 degrees Celsius
Valley
Valley 3 degrees Celsius 5 degrees Celsius 4 degrees Celsius 6 degrees Celsius 6 degrees Celsius 6 degrees Celsius
Freezing Level Freezing Level
1000m
1000m
1000m
1100m
1100m
1100m

Additional weather information

Meteorologist's view

Frequent and locally heavy showers will bring a very changeable day. Care needed if heading into the hills with temperatures feeling cold at height, some gusty winds and a risk of thunder. UV levels also remaining high in any brighter spells.

Weather

Scattered showers continuing on Thursday with heavy downpours at times, and perhaps hail. A small chance of thunderstorms during the afternoon and a few brighter spells. Showers easing into the night. Feeling cold with brisk winds continuing.

Chance of cloud-free hill tops

70% dropping in heavy downpours.

Low cloud and visibility

Cloud down to 600-800 m at times, lowering in any intense or persistent showers. Visibility will generally be very good, although falling rapidly within any heavy showers to become moderate to poor.

Ground conditions

Please see - https://yrwyddfa.live/

Summit specific forecast