Mountain weather

Eryri / Snowdonia

Eryri / Snowdonia Mountain weather forecast table

Confidence

High becoming Medium from Sunday.

Sunrise:
Sunset:
Mountain hazards

Mountain weather hazards

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

hazard 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.

hazard 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.

hazard Blizzards
Blizzards and whiteouts present challenging and serious conditions due to a combination of falling or blowing snow, strong winds and cold temperatures. They can be highly disorientating, often resulting in near-zero visibility with limited or no visual references and no distinction between ground and sky. Cliff edges and cornices may not be apparent, even close up. These conditions require very good navigational skills.
hazard Heavy Persistent Snow
Heavy snow can lead to rapid changes in underfoot conditions and paths may become treacherous or hidden. It also brings very poor visibility and often makes navigation much more challenging. When deep snow accumulates progress is often time consuming and strenuous, significantly affecting the distance one can travel on foot. Deep drifts can develop if snow is combined with strong winds. A heightened avalanche risk is possible and avalanche reports should be consulted where available.
hazard 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

Cloudy with outbreaks of rain. Summit snow later. Poor visibility.

Time 06:00 09:00 12:00 15:00 18:00 21:00
Weather
(at 800m)
Fog Heavy rain Heavy rain Sleet Sleet Heavy snow
Chance of precipitation
(at 800m)
50% 60% 80% 70% 50% 60%

Wind direction and speed (mph)
Altitude above mean sea level
Time 06:00 09:00 12:00 15:00 18:00 21:00
900m N
7
N
7
E
10
S
13
SE
12
E
16
600m NW
4
NE
6
S
8
S
9
SE
9
SE
13
300m W
3
NW
3
SW
6
S
6
SE
6
E
10
Valley NW
3
NW
3
SW
6
S
7
SE
6
E
10
Wind gust (mph)
Altitude above mean sea level
Time 06:00 09:00 12:00 15:00 18:00 21:00
900m 8 9 13 17 15 22
600m 5 7 11 13 13 19
300m 4 5 9 10 11 17
Valley 4 5 10 10 11 17

Altitude above mean sea level
Time 06:00 09:00 12:00 15:00 18:00 21:00
900m
-1°
600m
300m
Valley
Freezing Level
1,300m
1,300m
1,200m
1,000m
1,000m
900m

Altitude above mean sea level
Time 06:00 09:00 12:00 15:00 18:00 21:00
900m
-2°
-4°
-4°
-7°
600m
-1°
-1°
-3°
300m
Valley

Additional weather information

Meteorologist's view

Some variation in Freezing Levels to be expected, those shown representative of the north of the park. Freezing Levels could be higher in the south in the evening, reducing the snow likelihood.

Weather

Mostly cloudy with outbreaks of rain, heavy at times. Turning to snow over the summits in the evening, giving temporary blizzard conditions.

Chance of cloud-free hill tops

30%

Low cloud and visibility

Occasional or extensive cloud, base 300 to 600m, perhaps occasionally lifting 600 to 900m. Visibility moderate to very poor in cloud, rain and snow, otherwise good.

Ground conditions

Please see - https://yrwyddfa.live/

Sunrise:
Sunset:

Mountain weather information

Weather

Outbreaks of snow and low level rain overnight turning to snow at most levels during the morning, heavy and persistent at times with blizzard conditions developing at height. The snow and any low level rain turning light and patchy during the afternoon, with clearing skies and a frost and ice developing in the evening. Strong to gale force northeast winds with a severe wind chill.

Chance of cloud-free hill tops

20% rising to 50% late afternoon and 90% in the evening.

Maximum wind speed expected

Northeast 25 to 35mph gusting 50mph.

Temperature

  • At 800m Minus 2 to Minus 5 Celsius
  • Valley Plus 1 to 3 Celsius, later Minus 2 Celsius
  • Freezing level 200 to 400m, later all levels.

Low cloud and visibility

Extensive low cloud, base 300 to 600m gradually lifting through the afternoon, before clearing during the evening. Visibility mostly moderate or very poor, but becoming very good or excellent later.

Mountain weather information

Sat 14 Feb

Sunrise:
Sunset:

Dry and bright with sunny or clear spells, a hard frost at first. Mostly light winds, but strengthening from the south in the evening, patchy snow by midnight. Freezing all levels at first, rising to around 300m

Sun 15 Feb

Sunrise:
Sunset:

Rain and snow with blizzard conditions for a time at height. Severe gale or storm force southerly winds, becoming strong to gale force from the west or southwest during daylight hours, the freezing level rising near or above the summits. Turning more showery.

Mon 16 Feb

Sunrise:
Sunset:

Showers or longer outbreaks of rain and snow as the freezing level lowers to around 600m. Gale to storm force northwest winds for a time. Severe wind chill.

Updated at:

Summit specific forecast

Mountain summit forecast map

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