Mountain weather

Eryri / Snowdonia

Eryri / Snowdonia Mountain weather forecast table

Confidence

High for showery conditions on Friday then confidence in the details decreasing through the weekend so please keep up to date with the forecast.

Sunrise:
Sunset:
Mountain hazards

Mountain weather hazards

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

hazard 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.

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.

Mountain weather forecast

Showers, some heavy, wintry on the tops. Cold and windy at height.

06:00 09:00 12:00 15:00 18:00 21:00
Weather
(at 800m)
Fog Fog Sleet shower (day) Sleet shower (day) Sleet shower (day) Cloudy
Chance of precipitation
(at 800m)
20% 30% 50% 50% 50% 30%

Wind direction and speed (mph)
Altitude above mean sea level
06:00 09:00 12:00 15:00 18:00 21:00
900m S
28
S
27
S
32
SW
34
SW
37
S
35
600m S
19
S
20
S
25
SW
26
SW
25
S
24
300m S
13
S
14
S
17
SW
18
S
17
S
16
Valley S
13
S
14
S
16
SW
17
S
16
S
16
Wind gust (mph)
Altitude above mean sea level
06:00 09:00 12:00 15:00 18:00 21:00
900m 33 35 42 45 47 45
600m 24 28 35 37 35 34
300m 23 24 31 32 31 30
Valley 24 24 28 30 29 29

Altitude above mean sea level
06:00 09:00 12:00 15:00 18:00 21:00
900m
600m
300m
Valley
Freezing Level
1,000m
1,000m
1,000m
1,100m
1,000m
1,000m

Altitude above mean sea level
06:00 09:00 12:00 15:00 18:00 21:00
900m
-7°
-6°
-4°
-5°
-6°
-7°
600m
-3°
-2°
-1°
-1°
-2°
-3°
300m
Valley

Additional weather information

Meteorologist's view

Strong winds on the tops with gusts of 40 to 50mph on exposed ridges and summits. Feeling cold as you gain height with a significant wind chill.

Weather

A mixture of bright intervals and showers, falling as sleet or snow above 700m. Some showers could be heavy with hail and a chance of lightning. A few showers will continue into the evening with lengthening clear spells.

Chance of cloud-free hill tops

20% becoming 40%. Cloud will come and go from the summits at times.

Low cloud and visibility

Patchy cloud and fog mainly above 700m but locally down to 400m in showers. Outside of low cloud, visibility mainly good, reducing to a few km or less in showers.

Ground conditions

Please see - https://yrwyddfa.live/

Sunrise:
Sunset:

Mountain weather information

Weather

Clear spells and patchy mist overnight. This will clear during then morning then a few isolated showers developing, wintry above 800m. Becoming dry with lengthening spells of sunshine in the afternoon then a dry, clear evening.

Chance of cloud-free hill tops

30% at first then becoming 80%.

Maximum wind speed expected

Southerly 20mph gusts 30mph.

Temperature

  • At 800m Plus 2C rising to 4C.
  • Valley Plus 5C rising to 11C.
  • Freezing level 900m, rising above summits in afternoon.

Low cloud and visibility

Areas of low cloud and fog above 500m at first, gradually lifting. Otherwise mostly good visibility with patchy summit fog in showers.

Mountain weather information

Sun 31 Mar

Sunrise:
Sunset:

Dry with bright spells but still feeling rather chilly on the tops. Light south-easterly winds. Freezing level above summits.

Mon 1 Apr

Sunrise:
Sunset:

Mainly dry but a few isolated showers developing, wintry above 600m. Light southerly winds. Feeling cold on the tops with freezing level 800 or 900m.

Tue 2 Apr

Sunrise:
Sunset:

Mainly dry but showers may develop through the afternoon. Freezing level 800m, rising above summits. Light southerly winds.

Updated at:

Summit specific forecast

Mountain summit forecast map

Loading map…