Mountain weather

Mountain weather

Eryri / Snowdonia

Confidence

High for continued changeable conditions. Low with respect to heaviest showers.

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.

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.

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.
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.

Mountain weather forecast

Cloud and rain clearing to drier and brighter weather.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Light rain showers (night) Light rain showers Sunny intervals Light rain showers Light rain showers Partly cloudy (night)
Chance of
precipitation
(at 800m)
Chance of precipitation
50%
40%
30%
50%
40%
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 W 23mph knots
W
23mph
W 23mph knots
W
23mph
W 23mph knots
W
23mph
W 22mph knots
W
22mph
W 22mph knots
W
22mph
NW 24mph knots
NW
24mph
600m
600m W 14mph knots
W
14mph
W 16mph knots
W
16mph
W 17mph knots
W
17mph
W 16mph knots
W
16mph
W 14mph knots
W
14mph
W 14mph knots
W
14mph
300m
300m W 8mph knots
W
8mph
W 12mph knots
W
12mph
W 13mph knots
W
13mph
W 13mph knots
W
13mph
W 9mph knots
W
9mph
W 9mph knots
W
9mph
Valley
Valley W 8mph knots
W
8mph
W 12mph knots
W
12mph
W 13mph knots
W
13mph
W 13mph knots
W
13mph
W 10mph knots
W
10mph
W 9mph knots
W
9mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 28mph 29mph 30mph 29mph 28mph 30mph
600m
600m 19mph 23mph 24mph 23mph 19mph 21mph
300m
300m 17mph 21mph 22mph 22mph 17mph 18mph
Valley
Valley 17mph 20mph 22mph 22mph 17mph 19mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 5 degrees Celsius 4 degrees Celsius 3 degrees Celsius 4 degrees Celsius 3 degrees Celsius 3 degrees Celsius
600m
600m 8 degrees Celsius 8 degrees Celsius 8 degrees Celsius 8 degrees Celsius 7 degrees Celsius 7 degrees Celsius
300m
300m 11 degrees Celsius 11 degrees Celsius 11 degrees Celsius 11 degrees Celsius 11 degrees Celsius 10 degrees Celsius
Valley
Valley 13 degrees Celsius 12 degrees Celsius 12 degrees Celsius 13 degrees Celsius 12 degrees Celsius 12 degrees Celsius
Freezing Level Freezing Level
2200m
2200m
1800m
2100m
2000m
2000m

Additional weather information

Meteorologist's view

Once earlier morning cloud and rain clear south it will be a pleasant day for outdoor activities in the national park. Ground may initially be wet underfoot though the morning. Through the afternoon visibilities may drop briefly in showers and waterproofs are recommended. UV levels are expected to be moderate or high, so sun protection is advised.

Weather

Cloudy at first with scattered showers some of which may be heavy. Beyond this a drier and brighter day with the potential for some scattered showers through the afternoon and just a small chance of a thunderstorm.

Chance of cloud-free hill tops

20% initially gradually rising to >95% through the morning.

Low cloud and visibility

Cloud bases initially between 500-600m, but by mid-morning all cloud bases are expected to lift above summits. Good visibilities initially but poor or very poor in low cloud and hill fog. Visibilities becoming very good or excellent through the morning with views of distant peaks possible, potentially dropping to moderate in any passing showers.

Ground conditions

No recent ground conditions report available.

Summit specific forecast