Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High for general themes. Medium for cloud detail.
This evening forecast
Cloudy with patchy light rain and drizzle, snow flurries over the summits. Chilly easterly winds, strong at times.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
Gales
Gale force winds (gusts over 50mph) make walking difficult and strenuous with a potential to be blown over by gusts. There is often a marked increase in winds through cols or on exposed ridges and summits. Distances can take longer to cover and compass bearings become harder to follow accurately.
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.
Storm Force Winds
Storm force winds (gusts over 70mph) make walking very strenuous with any mobility virtually impossible over exposed ground. Where these conditions occur there is a high risk of being blown over and even standing may be impossible at times with a risk of being blown off one’s feet. Basic tasks such as using a map, eating, putting on extra clothing or communication become extremely difficult away from any shelter.
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
Dry. Severe wind chill. Sunny or clear spells possible.
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
|
|
Chance of precipitation (at 800m) |
40% | 40% | 30% | 20% | 10% | <05% | <05% | 10% |
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
30
|
E
34
|
E
37
|
E
44
|
E
41
|
E
38
|
E
37
|
E
33
|
| 600m |
E
22
|
E
22
|
E
24
|
E
30
|
E
31
|
E
24
|
E
23
|
E
23
|
| 300m |
E
13
|
E
12
|
E
11
|
E
17
|
E
22
|
E
13
|
E
13
|
E
16
|
| Valley |
E
13
|
E
12
|
E
10
|
E
17
|
E
21
|
E
13
|
E
13
|
E
16
|
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 | 39 | 43 | 45 | 53 | 49 | 47 | 48 | 43 |
| 600m | 33 | 33 | 36 | 42 | 44 | 35 | 36 | 34 |
| 300m | 24 | 22 | 23 | 32 | 38 | 24 | 25 | 31 |
| Valley | 24 | 22 | 22 | 31 | 37 | 23 | 24 | 29 |
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
0°
|
-1°
|
-2°
|
-2°
|
-3°
|
-2°
|
-2°
|
-2°
|
| 600m |
1°
|
1°
|
1°
|
0°
|
1°
|
0°
|
0°
|
0°
|
| 300m |
3°
|
3°
|
2°
|
2°
|
2°
|
2°
|
2°
|
2°
|
| Valley |
4°
|
4°
|
3°
|
3°
|
4°
|
3°
|
3°
|
3°
|
| Freezing Level |
900m
|
600m
|
400m
|
300m
|
300m
|
400m
|
400m
|
400m
|
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
-9°
|
-10°
|
-11°
|
-12°
|
-13°
|
-12°
|
-12°
|
-11°
|
| 600m |
-5°
|
-6°
|
-6°
|
-7°
|
-7°
|
-7°
|
-7°
|
-7°
|
| 300m |
-1°
|
-2°
|
-2°
|
-4°
|
-4°
|
-2°
|
-3°
|
-4°
|
| Valley |
0°
|
0°
|
-1°
|
-2°
|
-2°
|
-1°
|
-1°
|
-2°
|
Additional weather information
Meteorologist's view
Nothing further to add.
Weather
Mainly dry, although the low cloud could be thick enough at times overnight and early morning to give patchy light rain or drizzle with or snow flurries across the summits. The low cloud lifting and breaking during the morning with some sunny or clear spells possible during the afternoon and evening. Gales and a severe wind chill at height.
Chance of cloud-free hill tops
20% becoming 80% by afternoon.
Low cloud and visibility
Occasional or extensive cloud overnight and early morning, base 300 to 600m, this lifting and breaking near or above the summit in the afternoon. Visibility moderate to very poor early, otherwise good or very good.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Early low cloud possible, but dry and mainly bright with some sunny or clear spells. Very windy with a severe chill, gale or storm force winds over the summits with significant buffeting.
Chance of cloud-free hill tops
40% becoming 80%
Maximum wind speed expected
East or Northeast 40mph gusting 60 to 70mph. Severe wind chill and buffeting
Temperature
- At 800m Zero to Minus 3 Celsius.
- Valley Zero to Plus 6 Celsius.
- Freezing level Rising 600m by day, but most levels at night.
Low cloud and visibility
Occasional or extensive cloud possible early and later, base 600m, but often well broken or clear with any cloud above the summits. Visibility moderate to very poor in any cloud, otherwise good or very good.
Mountain weather information
Fri 26 Dec
Sunrise:
Sunset:
Dry and often clear or sunny. Widespread frost at night, but freezing level rising to around the summits by day. Severe wind chill. Strong to gale force easterly winds at height.
Sat 27 Dec
Sunrise:
Sunset:
Mainly dry. Variable cloud. Lowering temperature inversion could see the summits become clear even if the cloud is rather extensive. Wind chill. Fresh to strong east or northeast winds at height. Freezing level mainly near the summits, but a frost possible at all levels early and late.
Sun 28 Dec
Sunrise:
Sunset:
Mainly dry. Variable cloud. Lowering temperature inversion could see the summits become clear even if the cloud is rather extensive. Moderate east or northeast winds at height. Freezing level mainly near the summits, but a frost possible at all levels early and late.
Updated at:
Summit specific forecast
Mountain summit forecast map
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Key
Mountain summits
Other points of interest
Cluster of multiple stations
The Eryri (Snowdonia) mountains are made up of 90 mountain peaks including the tallest mountain in Wales, Yr Wyddfa (Snowdon), standing at 1,085 metres.