Mountain weather

Eryri / Snowdonia

Eryri / Snowdonia Mountain weather forecast table

Confidence

Usual uncertainties in distribution and organisation of shower bands.

Sunrise:
Sunset:
Mountain hazards

Mountain weather hazards

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

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 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 Strong Sunlight
Harmful UV levels from sunlight increase with altitude giving a greater risk of sunburn and eye damage, even on some overcast days. On breezy days, the cooling effect of wind on exposed skin may disguise any feeling of sunburn until it is too late. If there is snow cover, glare increases the effect of UV rays especially on the eyes. It is advisable to wear sun block, protective clothing such as a long-sleeved top and hat and have good quality eye protection.

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

Winds gradually easing. Sunny spells and some scattered showers in the afternoon.

Time 06:00 09:00 12:00 15:00 18:00 21:00
Weather
(at 800m)
Fog Sunny intervals Sunny intervals Light shower (day) Light shower (day) Partly cloudy (night)
Chance of precipitation
(at 800m)
20% <5% <5% 40% 40% 30%

Wind direction and speed (mph)
Altitude above mean sea level
Time 06:00 09:00 12:00 15:00 18:00 21:00
900m SW
40
SW
32
SW
28
SW
26
SW
20
SW
14
600m SW
24
SW
25
SW
22
SW
20
SW
15
S
10
300m SW
14
SW
17
SW
16
SW
14
SW
10
S
6
Valley SW
15
SW
17
SW
15
SW
14
SW
10
S
6
Wind gust (mph)
Altitude above mean sea level
Time 06:00 09:00 12:00 15:00 18:00 21:00
900m 47 40 35 34 25 18
600m 32 33 29 27 19 13
300m 29 29 26 24 17 11
Valley 29 29 25 23 17 11

Altitude above mean sea level
Time 06:00 09:00 12:00 15:00 18:00 21:00
900m
600m
300m
Valley
Freezing Level
1,000m
1,000m
900m
1,000m
900m
800m

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

Additional weather information

Meteorologist's view

A chilly and blustery day ahead so layers and waterproofs advised.

Weather

Patchy low cloud soon lifting to give a largely dry and bright start, with some sunny spells. Windy on the summit, with gales. There is likely to be some scattered blustery showers during the afternoon, although these will be less frequent than on Saturday. Winds gradually easing.

Chance of cloud-free hill tops

60% early on, otherwise 80%.

Low cloud and visibility

Patchy low cloud early on down to 500-700 m, otherwise cloud above summits. Very poor initially then rising to good or very good outside showers.

Ground conditions

Please see - https://yrwyddfa.live/

Sunrise:
Sunset:

Mountain weather information

Weather

A chilly start. Winds much lighter than recent days though the risk of showers continues. These will tend to be scattered across the park at times during the day, and may turn heavy. Plenty of sunny spells in between any showers. Temperatures similar to Sunday but feeling more pleasant in lighter winds.

Chance of cloud-free hill tops

60% early on, otherwise 80%.

Maximum wind speed expected

10-15 mph.

Temperature

  • At 800m Plus 4 Celsius rising to 10 Celsius.
  • Valley Minus 2 Celsius rising to plus 10 Celsius.
  • Freezing level Just above summits.

Low cloud and visibility

Patchy low cloud early on down to 600-700 m, otherwise cloud above summits. Cloud bases may drop briefly in any heavier downpours. Poor visibility to start but then becoming good or very good visibility outside of showers.

Mountain weather information

Tue 14 Apr

Sunrise:
Sunset:

Fine and dry during the early hours but cloud bases lowering as patchy outbreaks of rain and drizzle move in from the west through the day. Freezing level above summits. Light winds.

Wed 15 Apr

Sunrise:
Sunset:

Wet and windy with heavy outbreaks of rain creating very poor visibility across the park at times alongside low cloud bases. Moderate to strong southerly winds.

Thu 16 Apr

Sunrise:
Sunset:

Returning to sunshine and showers. Lighter winds.

Updated at:

Summit specific forecast

Mountain summit forecast map

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