Mountain weather

Mountain weather

Eryri / Snowdonia

Confidence

Moderate for the overall story. Low confidence on any light showers passing through on Friday and the timing of any rain on Monday.

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.
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.

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

A cloudy day with potential for showers. Brightening up later.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Drizzle Cloudy Light rain showers Light rain showers Cloudy Partly cloudy (night)
Chance of
precipitation
(at 800m)
Chance of precipitation
40%
20%
40%
40%
10%
10%

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 12mph knots
W
12mph
W 10mph knots
W
10mph
W 12mph knots
W
12mph
N 13mph knots
N
13mph
N 17mph knots
N
17mph
N 19mph knots
N
19mph
600m
600m SW 8mph knots
SW
8mph
W 8mph knots
W
8mph
NW 9mph knots
NW
9mph
N 11mph knots
N
11mph
N 11mph knots
N
11mph
N 7mph knots
N
7mph
300m
300m SW 4mph knots
SW
4mph
W 5mph knots
W
5mph
NW 6mph knots
NW
6mph
N 8mph knots
N
8mph
N 8mph knots
N
8mph
NW 4mph knots
NW
4mph
Valley
Valley SW 4mph knots
SW
4mph
W 5mph knots
W
5mph
NW 7mph knots
NW
7mph
N 8mph knots
N
8mph
N 8mph knots
N
8mph
NW 4mph knots
NW
4mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 14mph 13mph 15mph 16mph 22mph 24mph
600m
600m 10mph 10mph 11mph 15mph 15mph 11mph
300m
300m 6mph 7mph 9mph 12mph 13mph 10mph
Valley
Valley 6mph 7mph 9mph 12mph 13mph 10mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 13 degrees Celsius 14 degrees Celsius 13 degrees Celsius 9 degrees Celsius 8 degrees Celsius 7 degrees Celsius
600m
600m 16 degrees Celsius 16 degrees Celsius 16 degrees Celsius 12 degrees Celsius 12 degrees Celsius 12 degrees Celsius
300m
300m 19 degrees Celsius 20 degrees Celsius 18 degrees Celsius 15 degrees Celsius 15 degrees Celsius 15 degrees Celsius
Valley
Valley 20 degrees Celsius 21 degrees Celsius 19 degrees Celsius 17 degrees Celsius 17 degrees Celsius 16 degrees Celsius
Freezing Level Freezing Level
3600m
3500m
3300m
3000m
2700m
2500m

Additional weather information

Meteorologist's view

A rather mixed day in the national park with a potential for some poor visibility making navigation challenging initially. The cloudy and showery conditions make taking waterproofs advisable for showers. Although it will be cloudy UV levels will still be reasonable high so sun protection should be considered.

Weather

Patchy low cloud and drizzle initially, mainly to the west of the park which may shroud highest routes at times, although brighter conditions expected further east. Turning gradually cloudier through the morning with limited brightness, and the showers possible, these may be locally heavy with the odd rumble of thunder. Shower risk dying out later with skies turning brighter once more. Clouding over after dusk.

Chance of cloud-free hill tops

30% at first, becoming more widely 90% late in the afternoon.

Low cloud and visibility

Broken low cloud at first with bases 300-400m likely, lifting above most summits by the late afternoon. Visibility will be moderate to poor in any low cloud first thing and in showers, increasing to very good late in the afternoon.

Ground conditions

Please see - https://yrwyddfa.live/

Summit specific forecast