Mountain weather

Eryri / Snowdonia

Yellow warning

Yellow weather warning in force for Eryri / Snowdonia

Eryri / Snowdonia Mountain weather forecast table

Confidence

Generally high throughout the forecast period with the main uncertainties around cloud amounts and height of the cloud inversion.

Sunrise:
Sunset:
Mountain hazards

Mountain weather hazards

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

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 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.
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.

Mountain weather forecast

Dry and becoming widely sunny, but severe wind chill with summit gales.

Time 06:00 09:00 12:00 15:00 18:00 21:00
Weather
(at 800m)
Cloudy Sunny day Sunny day Clear night Clear night Clear night
Chance of precipitation
(at 800m)
<05% 00% 00% 00% 00% 00%

Wind direction and speed (mph)
Altitude above mean sea level
Time 06:00 09:00 12:00 15:00 18:00 21:00
900m E
36
E
38
NE
35
E
44
E
47
E
48
600m E
27
E
24
E
26
E
29
E
34
E
36
300m E
18
NE
13
NE
16
NE
17
E
22
E
24
Valley E
18
NE
13
NE
16
E
16
E
22
E
24
Wind gust (mph)
Altitude above mean sea level
Time 06:00 09:00 12:00 15:00 18:00 21:00
900m 43 45 42 52 57 58
600m 33 29 33 37 44 46
300m 29 24 26 30 40 42
Valley 29 24 26 30 39 41

Altitude above mean sea level
Time 06:00 09:00 12:00 15:00 18:00 21:00
900m
-4°
-4°
-4°
-3°
-3°
-4°
600m
-1°
-1°
-1°
-1°
-1°
300m
Valley
Freezing Level
300m
300m
400m
400m
400m
300m

Altitude above mean sea level
Time 06:00 09:00 12:00 15:00 18:00 21:00
900m
-14°
-14°
-13°
-14°
-14°
-14°
600m
-10°
-9°
-9°
-8°
-9°
-10°
300m
-4°
-4°
-3°
-3°
-5°
-6°
Valley
-3°
-2°
-2°
-1°
-3°
-4°

Additional weather information

Meteorologist's view

Gusts are likely to reach 55-60 mph over the higher summits, occasionally 70-75 mph in the evening with a high risk of being blown over. Severe wind chill expected today.

Weather

Patchy cloud in the morning, mainly across the north and east of the Park, otherwise a dry and largely sunny Christmas day, but bitterly cold on the tops in gale force summit winds. Clear skies in the evening, but winds strengthening further.

Chance of cloud-free hill tops

60% in north and east in the morning. Otherwise 90% or more.

Low cloud and visibility

Occasional cloud above 600m, mainly north and east in the morning, but dispersing soon after dawn to give excellent visibility with no cloud on the hills.

Ground conditions

Please see - https://yrwyddfa.live/

Sunrise:
Sunset:

Mountain weather information

Weather

Dry with clear or sunny skies throughout, but bitterly cold in strong winds with summit gales again.

Chance of cloud-free hill tops

90% or more.

Maximum wind speed expected

East 50 gusting 60-70 mph.

Temperature

  • At 800m Plus 1 or 2 Celsius.
  • Valley Minus 2 Celsius rising to plus 3 Celsius.
  • Freezing level 300m rising to 600m, but the summits above freezing.

Low cloud and visibility

Excellent visibility with no cloud expected on the hills.

Mountain weather information

Sat 27 Dec

Sunrise:
Sunset:

Mostly dry and sunny, but cloud spreads west later in the day, although summits likely to remain clear. Cold with easterly gales. Freezing level around 500m rising to 900m.

Sun 28 Dec

Sunrise:
Sunset:

A dull day with hill fog and a little patchy light drizzle at times, although the highest summits likely to be above the cloud. Moderate to fresh easterly winds. Freezing level 700m.

Mon 29 Dec

Sunrise:
Sunset:

Brighter than Sunday, but still rather cloudy with hill fog on the tops. Best of any sunshine in the west. Moderate easterly winds. Freezing level 500m.

Updated at:

Summit specific forecast

Mountain summit forecast map

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