Mountain weather

Eryri / Snowdonia

Eryri / Snowdonia Mountain weather forecast table

Confidence

High for an unsettled couple of days. Moderate for a transition to more settled conditions over the weekend.

Sunrise:
Sunset:

This evening forecast

Largely cloudy this evening, especially in the east of the park. Any early showers clearing, becoming dry.

Sunrise:
Sunset:
Mountain hazards

Mountain weather hazards

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

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

Cloudy with outbreaks of heavy showery rain.

00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
Weather
(at 800m)
Clear night Clear night Sunny day Sunny intervals Heavy shower (day) Light rain Heavy rain Light rain
Chance of precipitation
(at 800m)
<05% <05% <05% 20% 40% 60% 60% 40%

Wind direction and speed (mph)
Altitude above mean sea level
00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
900m E
12
E
10
E
8
NE
6
N
8
N
11
NW
8
NW
9
600m SE
9
SE
8
E
6
N
7
N
8
N
10
NW
7
NW
5
300m SE
7
SE
5
E
4
N
5
N
7
N
8
NW
4
NW
3
Valley SE
7
SE
6
SE
4
N
5
N
8
N
7
NW
4
W
4
Wind gust (mph)
Altitude above mean sea level
00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
900m 14 12 11 9 12 16 11 13
600m 12 10 8 10 13 14 10 8
300m 11 9 6 9 11 13 8 7
Valley 11 10 7 9 13 12 7 6

Altitude above mean sea level
00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
900m
10°
11°
11°
600m
11°
10°
11°
12°
13°
13°
11°
10°
300m
12°
12°
13°
15°
15°
15°
13°
12°
Valley
13°
13°
14°
16°
16°
16°
14°
13°
Freezing Level
2,000m
1,900m
1,900m
2,000m
2,100m
2,200m
2,300m
2,400m

Altitude above mean sea level
00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
900m
10°
600m
10°
11°
12°
11°
10°
300m
11°
11°
12°
14°
14°
14°
13°
12°
Valley
12°
12°
13°
15°
15°
15°
14°
12°

Additional weather information

Meteorologist's view

A good start to the day, sun protection advised. Waterproofs recommended in the afternoon.

Weather

A dry and clear early morning period. Sunny through the morning, gradually becoming cloudier. A chance of showers early afternoon, these perhaps heavy with a small risk of thunder. Becoming increasingly cloudy from the east later in the afternoon and evening with rain, which may turn heavy for a time. Cloud lowering again into the evening.

Chance of cloud-free hill tops

80% through the morning and afternoon, 40% later.

Low cloud and visibility

Some low cloud to the west of the park initially but soon clearing. Bases generally above summits by day, lowering from late afternoon associated with rainfall to 600-700m. Good visibility with clear views of distant hills, moderate in rain or showers, poor in cloud at elevation later.

Ground conditions

Please see - https://yrwyddfa.live/

Sunrise:
Sunset:

Mountain weather information

Weather

A cloudy and murky start on Friday with low cloud covering hill tops and outbreaks of rain. Cloud lifting and breaking through the day, some brief brighter spells in the afternoon and the risk of an isolated heavy perhaps thundery shower.

Chance of cloud-free hill tops

20% initially, becoming 80% by mid-morning.

Maximum wind speed expected

Northerly 17 mph.

Temperature

  • At 800m Plus 10 Celsius.
  • Valley Plus 12 Celsius becoming 18 Celsius.
  • Freezing level Above summits.

Low cloud and visibility

Extensive cloud down to 300-400m initially, lifting and breaking through the morning, rising above summits. Visibility poor in cloud initially, becoming generally good at all elevations later with clear views of distant hills. Perhaps briefly moderate in isolated showers.

Mountain weather information

Sat 18 May

Sunrise:
Sunset:

A brighter day but once again with a chance of heavy thundery showers. Freezing level above summits.

Sun 19 May

Sunrise:
Sunset:

Partly cloudy, with sunny intervals, mostly dry. Freezing level above summits.

Mon 20 May

Sunrise:
Sunset:

Bright initially, a chance of heavy thundery showers. Freezing level above summits.

Updated at:

Summit specific forecast

Mountain summit forecast map

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