Mountain weather

Mountain weather

Eryri / Snowdonia

Confidence

High for unsettled wet conditions today. Moderate for extent of heavier outbreaks of rain during the day and colder air overnight, allowing for patchy precipitation to turn to snow at height. Low for timing and phase of precipitation Monday night which may produce blizzard conditions and accumulating snow at height.

Sunrise: Sunset:
Sunrise: Sunset:
Mountain hazards

Mountain weather hazards

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

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.

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.
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.

Mountain weather forecast

An unsettled day with heavy rain.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Light rain Heavy Rain Heavy Rain Heavy Rain Light rain showers (night) Sleet showers (night)
Chance of
precipitation
(at 800m)
Chance of precipitation
40%
70%
70%
70%
30%
30%

Wind direction and speed

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m S 22mph knots
S
22mph
SE 18mph knots
SE
18mph
S 13mph knots
S
13mph
NW 19mph knots
NW
19mph
NW 33mph knots
NW
33mph
NW 33mph knots
NW
33mph
600m
600m S 18mph knots
S
18mph
S 14mph knots
S
14mph
S 10mph knots
S
10mph
NW 10mph knots
NW
10mph
NW 20mph knots
NW
20mph
NW 21mph knots
NW
21mph
300m
300m S 12mph knots
S
12mph
SE 9mph knots
SE
9mph
S 7mph knots
S
7mph
NW 6mph knots
NW
6mph
NW 13mph knots
NW
13mph
NW 14mph knots
NW
14mph
Valley
Valley S 12mph knots
S
12mph
SE 9mph knots
SE
9mph
S 7mph knots
S
7mph
NW 5mph knots
NW
5mph
NW 13mph knots
NW
13mph
NW 14mph knots
NW
14mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 28mph 25mph 18mph 22mph 39mph 40mph
600m
600m 26mph 22mph 15mph 13mph 26mph 28mph
300m
300m 25mph 19mph 14mph 9mph 23mph 26mph
Valley
Valley 25mph 19mph 14mph 9mph 23mph 26mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m -3 degrees Celsius -1 degrees Celsius 0 degrees Celsius -1 degrees Celsius -6 degrees Celsius -8 degrees Celsius
600m
600m 0 degrees Celsius 2 degrees Celsius 3 degrees Celsius 2 degrees Celsius -2 degrees Celsius -4 degrees Celsius
300m
300m 3 degrees Celsius 5 degrees Celsius 6 degrees Celsius 6 degrees Celsius 3 degrees Celsius 1 degrees Celsius
Valley
Valley 4 degrees Celsius 6 degrees Celsius 7 degrees Celsius 7 degrees Celsius 4 degrees Celsius 3 degrees Celsius
Freezing Level Freezing Level
1700m
1700m
1700m
1500m
1000m
800m

Additional weather information

Meteorologist's view

Poor walking conditions with widespread rain (locally heavy), along with low cloud and hill fog making visibility difficult during the afternoon. Waterproofs may become drenched with the risk of a few watercourses becoming swollen during the evening. Towards midnight the freezing level falling with any patches of precipitation turning wintry at height. NW'ly winds strengthening during the evening adding to the severe wind chill as the summits fall below freezing.

Weather

Rain gradually spreading from the SW and locally turning heavy from late morning with low cloud becoming extensive generating widespread hill fog. Wet conditions with poor visibility lasting much of the day with only a few breaks at times. During the evening rain turning more showery, with colder air from the NW producing snow showers over 800 M. Clear spells emerging. SE'ly winds veering and strengthening to NW'ly gusting 30 mph at height.

Chance of cloud-free hill tops

Initially 50% decreasing to 10% under extensive cloud and rain. 50% later towards midnight.

Low cloud and visibility

Patchy summit cloud initially before low cloud and hill fog becomes more extensive above 400 M during the afternoon. Visibility turning poor to very poor under heavy rain and low cloud. Clearer spells towards midnight.

Ground conditions

No recent ground conditions report available.

Summit specific forecast