Mountain weather

Eryri / Snowdonia

Eryri / Snowdonia Mountain weather forecast table

Confidence

High for changeable weather to continue for the rest of the week

Sunrise:
Sunset:

This evening forecast

Mainly dry and cloudy with patchy rain across developing across the west towards midnight. Areas of cloud down to 700 metres developing later. Strong to gale southwesterly summit winds.

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 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 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 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

Windy with rain spreading south in the afternoon. Colder with wintry showers by evening

Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
Weather
(at 800m)
Cloudy Cloudy Cloudy Light rain Heavy rain Heavy rain Sleet Sleet
Chance of precipitation
(at 800m)
20% 20% 20% 30% >95% >95% 60% 60%

Wind direction and speed (mph)
Altitude above mean sea level
Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
900m SW
37
SW
37
SW
37
SW
41
SW
41
SW
38
SW
33
W
34
600m SW
24
SW
24
SW
24
SW
26
SW
27
SW
27
SW
24
W
24
300m SW
16
SW
17
SW
16
SW
18
SW
19
SW
19
SW
16
W
18
Valley SW
17
SW
17
SW
16
SW
17
SW
20
SW
18
SW
16
W
18
Wind gust (mph)
Altitude above mean sea level
Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
900m 46 47 47 52 54 50 46 46
600m 33 33 33 37 39 39 36 36
300m 29 31 31 33 36 35 31 33
Valley 30 31 30 32 36 34 30 33

Altitude above mean sea level
Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
900m
600m
300m
Valley
10°
10°
10°
Freezing Level
2,300m
2,200m
2,300m
2,300m
2,200m
1,700m
1,200m
800m

Altitude above mean sea level
Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
900m
-3°
-2°
-2°
-3°
-3°
-2°
-4°
-9°
600m
-5°
300m
-1°
Valley

Additional weather information

Meteorologist's view

Strong to gale summit winds will make for slow progress and a risk of being blown over. Combined with heavy rain in the afternoon be prepared for drenching and chilling conditions.

Weather

Cloudy in the morning with some patchy light rain, this mainly across the west of the area. Widespread heavy rain will spread southeast through the afternoon. Drier weather with showers following on during the evening, with showers turning to sleet and snow.

Chance of cloud-free hill tops

40%, best chance in the east in the morning

Low cloud and visibility

Poor in areas of cloud down to 500 to 800 metres, cloud lowest and most extensive across the west of the Park. Cloud somewhat higher and more broken across the east, more especially in the morning.

Ground conditions

Please see - https://yrwyddfa.live/

Sunrise:
Sunset:

Mountain weather information

Weather

Mostly cloudy with snow and hail showers. Showers easing through the evening. Strong to gale bitterly cold summit northwesterly winds.

Chance of cloud-free hill tops

70%

Maximum wind speed expected

Northwesterly average speeds 35 mph with gusts to 50 mph on the summits

Temperature

  • At 800m Minus 2 Celsius
  • Valley 0 rising to 7 Celsius
  • Freezing level 400 to 600 metres

Low cloud and visibility

Poor in snow showers and areas of cloud down to 850 metres as showers pass by. Good visibility outside of cloud and snow with small amounts of summit cloud.

Mountain weather information

Thu 26 Mar

Sunrise:
Sunset:

Mostly cloudy with a few sleet or snow showers. Rain and higher summit snow extending from the west towards midnight. Cold with strong northwesterly winds.

Fri 27 Mar

Sunrise:
Sunset:

Rain for a time in the early hours otherwise mainly dry and cloudy. Light winds.

Sat 28 Mar

Sunrise:
Sunset:

Cold and cloudy with a few light showers, wintry on the higher tops.

Updated at:

Summit specific forecast

Mountain summit forecast map

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