Mountain weather

Eryri / Snowdonia

Amber warning

Amber weather warnings in force for Eryri / Snowdonia

Eryri / Snowdonia Mountain weather forecast table

Confidence

Medium

Sunrise:
Sunset:
Mountain hazards

Mountain weather hazards

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

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 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.
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 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 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.

hazard Storm Force Winds
Storm force winds (gusts over 70mph) make walking very strenuous with any mobility virtually impossible over exposed ground. Where these conditions occur there is a high risk of being blown over and even standing may be impossible at times with a risk of being blown off one’s feet. Basic tasks such as using a map, eating, putting on extra clothing or communication become extremely difficult away from any shelter.

Mountain weather forecast

Mainly dry start. Heavy snow with blizzards possible later.

Time 06:00 09:00 12:00 15:00 18:00 21:00
Weather
(at 800m)
Fog Cloudy Light snow Heavy snow Heavy snow Heavy snow
Chance of precipitation
(at 800m)
10% 30% 50% 70% 90% 90%

Wind direction and speed (mph)
Altitude above mean sea level
Time 06:00 09:00 12:00 15:00 18:00 21:00
900m NW
14
SW
7
SE
4
E
19
NE
36
NE
39
600m W
7
SW
6
SE
4
E
13
NE
23
NE
26
300m W
3
S
3
SE
3
E
9
NE
14
NE
17
Valley W
3
S
3
SE
3
E
9
NE
14
NE
17
Wind gust (mph)
Altitude above mean sea level
Time 06:00 09:00 12:00 15:00 18:00 21:00
900m 16 10 6 24 44 47
600m 9 7 5 20 30 34
300m 7 7 5 17 26 30
Valley 8 7 5 17 25 29

Altitude above mean sea level
Time 06:00 09:00 12:00 15:00 18:00 21:00
900m
-1°
-1°
-2°
-3°
600m
-2°
300m
Valley
Freezing Level
900m
800m
700m
700m
500m
300m

Altitude above mean sea level
Time 06:00 09:00 12:00 15:00 18:00 21:00
900m
-5°
-4°
-3°
-8°
-12°
-14°
600m
-1°
-1°
-1°
-4°
-8°
-10°
300m
-1°
-4°
-6°
Valley
-2°
-5°

Additional weather information

Meteorologist's view

Note marked deterioration in conditions in the afternoon.

Weather

Overcast and misty with patchy light rain and snow early morning. Dry for a time with some morning brighter spells possible. Rain and snow arriving mid-afternoon, quickly becoming heavy and persistent with blizzard conditions at height along with a severe wind chill, white out conditions likely at times.

Chance of cloud-free hill tops

40%, for a time in the afternoon, otherwise 10% or less.

Low cloud and visibility

Overcast base 300 to 600m, possibly lifting and breaking near or above the summits in the afternoon. Visibility moderate to very poor in cloud and snow, perhaps becoming good for a time during the afternoon.

Ground conditions

Please see - https://yrwyddfa.live/

Sunrise:
Sunset:

Mountain weather information

Weather

Outbreaks of heavy snow overnight with blizzard conditions possible. The snow becoming more showery by the morning and expected to be mainly rain and sleet at lower levels. Snow and rain showers continuing during the afternoon and evening.

Chance of cloud-free hill tops

10% or less at first becoming 60% by afternoon.

Maximum wind speed expected

North or Northwest 45mph gusting 50-55mph at first with a severe wind chill and possible blizzard conditions across summits.

Temperature

  • At 800m Minus 4 Celsius
  • Valley Zero to Plus 3 Celsius
  • Freezing level Typically 300 to 500m, but could be lower early and late in the period.

Low cloud and visibility

Occasional or extensive cloud, base 300 to 600m lifting and breaking towards in summits, except in showers. Visibility often moderate to very poor at first in cloud and snow, becoming good at times later.

Mountain weather information

Sat 10 Jan

Sunrise:
Sunset:

Often dry, clear and cold with a widespread frost and freezing at most levels. Snow showers with rain or sleet low down. Moderate or fresh northwesterly winds.

Sun 11 Jan

Sunrise:
Sunset:

Starting dry with bright or clear spells. Cold. Rain and snow later with blizzard conditions developing at height along with severe gale southerly winds.

Mon 12 Jan

Sunrise:
Sunset:

Milder with rain or showers. Strong to gale force southwest winds.

Updated at:

Summit specific forecast

Mountain summit forecast map

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