Mountain weather

Eryri / Snowdonia

Eryri / Snowdonia Mountain weather forecast table

Confidence

Generally high but moderate for the risk of showers on Thursday and Friday and low for the coming weekend in terms of details of rain and strength of winds.

Sunrise:
Sunset:

This evening forecast

Largely cloudy and dry with occasional bursts of sunshine in places this evening.

Sunrise:
Sunset:
Mountain hazards

Mountain weather hazards

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

hazard 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.
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.

Mountain weather forecast

Generally cloudy, sunny intervals developing. Low risk of a light shower.

Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
Weather
(at 800m)
Cloudy Light shower (night) Cloudy Cloudy Cloudy Sunny intervals Sunny intervals Partly cloudy (night)
Chance of precipitation
(at 800m)
30% 60% 30% 30% 20% 20% 20% 20%

Wind direction and speed (mph)
Altitude above mean sea level
Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
900m E
16
E
14
E
12
E
11
SE
9
S
5
SW
7
S
10
600m E
10
E
11
E
10
E
9
SE
6
W
4
SW
6
S
8
300m E
8
E
9
E
8
E
8
NE
5
W
4
SW
4
S
3
Valley E
8
E
8
E
8
E
8
NE
5
N
4
NW
4
S
3
Wind gust (mph)
Altitude above mean sea level
Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
900m 20 20 16 15 12 7 10 12
600m 17 19 15 13 9 7 8 10
300m 15 17 15 13 8 6 6 7
Valley 15 17 15 12 8 6 6 7

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

Altitude above mean sea level
Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
900m
-3°
-4°
-4°
-3°
600m
300m
Valley
10°
10°
10°

Additional weather information

Meteorologist's view

Feeling cold for early May with brisk winds on the summits through the morning giving a significant wind chill. Extra layers of clothing are advised. UV levels will be moderate to high through the midday hours, despite the cloud cover, so skin protection is advised.

Weather

Showers are possible through the early hours but these fading after dawn to leave a mainly dry day. Large amounts of cloud throughout much of Wednesday with occasional brighter periods and fleeting sunny intervals. A small chance of localised shower, these generally fairly light.

Chance of cloud-free hill tops

40% becoming 70%.

Low cloud and visibility

Periods of cloud above 700-800m, gradually lifting and clearing the summits. Poor or very poor visibility in any cloud/hill fog but otherwise generally very good visibility with far reaching views of surrounding peaks.

Ground conditions

Please see - https://yrwyddfa.live/

Sunrise:
Sunset:

Mountain weather information

Weather

Perhaps some early morning sunshine, but tending to quickly cloud over and thereafter remaining rather cloudy for the rest of the day. A greater risk of showers breaking out, especially late afternoon and into the evening, these becoming prolonged and heavy in places. There is considerable uncertainty regarding their location and some parts of the National Park will likely remain dry.

Chance of cloud-free hill tops

70%

Maximum wind speed expected

Southerly 20-25 mph.

Temperature

  • At 800m Plus 2 Celsius rising to plus 8 Celsius.
  • Valley Plus 4 Celsius rising to plus 16 Celsius.
  • Freezing level Above the summits.

Low cloud and visibility

Periods of cloud above 700-800m may form in association with afternoon and evening showers, but peaks will probably remain cloud free for large parts of the day.

Mountain weather information

Fri 8 May

Sunrise:
Sunset:

A similar day to Thursday with a mixture of sunny spells showers but a greater chance of heavy and thundery downpours developing. Feeling a little warmer with light to moderate southeasterly winds.

Sat 9 May

Sunrise:
Sunset:

Breezier with moderate to fresh easterly winds and a risk of showers. Uncertainty in the details but a possibility of a longer spell of heavy rain for a time.

Sun 10 May

Sunrise:
Sunset:

Probably unsettled with showers or more general rain, perhaps turning thundery. Moderate to fresh easterly winds.

Updated at:

Summit specific forecast

Mountain summit forecast map

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