Mountain weather

Mountain weather

Eryri / Snowdonia

Confidence

High overall but lower for extent of heavy showers on Saturday.

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.
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.
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.

Mountain weather forecast

A dry and bright start but showers by the afternoon.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Fog Sunny intervals Light rain showers Heavy rain showers Heavy Rain Light rain
Chance of
precipitation
(at 800m)
Chance of precipitation
20%
20%
50%
60%
50%
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 NE 7mph knots
NE
7mph
N 11mph knots
N
11mph
N 12mph knots
N
12mph
N 16mph knots
N
16mph
NE 22mph knots
NE
22mph
NE 25mph knots
NE
25mph
600m
600m N 4mph knots
N
4mph
N 8mph knots
N
8mph
N 11mph knots
N
11mph
N 14mph knots
N
14mph
NE 14mph knots
NE
14mph
E 12mph knots
E
12mph
300m
300m NW 3mph knots
NW
3mph
N 9mph knots
N
9mph
N 10mph knots
N
10mph
N 12mph knots
N
12mph
NE 12mph knots
NE
12mph
E 9mph knots
E
9mph
Valley
Valley NW 3mph knots
NW
3mph
N 8mph knots
N
8mph
N 10mph knots
N
10mph
N 12mph knots
N
12mph
NE 12mph knots
NE
12mph
E 9mph knots
E
9mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 10mph 15mph 16mph 21mph 28mph 34mph
600m
600m 5mph 12mph 15mph 19mph 21mph 22mph
300m
300m 4mph 14mph 16mph 19mph 22mph 21mph
Valley
Valley 4mph 13mph 16mph 19mph 21mph 20mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 3 degrees Celsius 3 degrees Celsius 3 degrees Celsius 2 degrees Celsius 0 degrees Celsius -3 degrees Celsius
600m
600m 7 degrees Celsius 6 degrees Celsius 7 degrees Celsius 5 degrees Celsius 4 degrees Celsius 2 degrees Celsius
300m
300m 8 degrees Celsius 8 degrees Celsius 10 degrees Celsius 8 degrees Celsius 8 degrees Celsius 6 degrees Celsius
Valley
Valley 9 degrees Celsius 10 degrees Celsius 11 degrees Celsius 10 degrees Celsius 9 degrees Celsius 8 degrees Celsius
Freezing Level Freezing Level
1700m
1700m
1700m
1700m
1700m
1600m

Additional weather information

Meteorologist's view

UV levels remain moderate to high, so sun protection is recommended.

Weather

Low cloud and hill fog lifting to leave a dry and bright start. Turning increasingly cloudy from midday with widespread showers across the park. These may turn heavy at times, before becoming more persistent spells of rain by the evening.

Chance of cloud-free hill tops

60%

Low cloud and visibility

Low cloud and hill fog down to 400-600m, only slowly lifting to mostly above summits by midday. Low cloud more extensive by the end of the day down to 700m. Good visibility but dropping to poor in low cloud and heavy showers.

Ground conditions

Please see - https://yrwyddfa.live/

Summit specific forecast