Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High for the generally settled and dry conditions over the next few days, but lower for any cloud detail.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
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.
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.
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
Most dry with occasional brighter spells.
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
<05% | <05% | <05% | <05% | <05% | <05% |
Wind direction and speed (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
E
29
|
E
26
|
E
19
|
E
17
|
E
20
|
E
19
|
| 600m |
E
17
|
E
17
|
E
15
|
E
14
|
E
13
|
E
14
|
| 300m |
SE
14
|
E
13
|
E
11
|
SE
10
|
E
9
|
E
9
|
| Valley |
SE
14
|
E
13
|
E
11
|
SE
10
|
E
8
|
E
9
|
Wind gust (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 37 | 34 | 25 | 22 | 26 | 25 |
| 600m | 28 | 27 | 21 | 19 | 21 | 20 |
| 300m | 26 | 25 | 20 | 18 | 18 | 18 |
| Valley | 26 | 25 | 19 | 18 | 18 | 18 |
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-1°
|
-2°
|
-2°
|
-1°
|
-2°
|
-1°
|
| 600m |
2°
|
2°
|
2°
|
2°
|
1°
|
1°
|
| 300m |
3°
|
3°
|
4°
|
4°
|
2°
|
2°
|
| Valley |
4°
|
3°
|
5°
|
5°
|
3°
|
3°
|
| Freezing Level |
700m
|
600m
|
600m
|
700m
|
600m
|
500m
|
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-10°
|
-10°
|
-9°
|
-7°
|
-9°
|
-8°
|
| 600m |
-4°
|
-4°
|
-3°
|
-3°
|
-4°
|
-5°
|
| 300m |
-2°
|
-2°
|
0°
|
0°
|
-1°
|
-1°
|
| Valley |
-1°
|
-1°
|
1°
|
1°
|
0°
|
0°
|
Additional weather information
Meteorologist's view
Freezing level figures above will be over simplistic at times as the inversion oscillates between 500m and 1000m resulting in a sub-zero layer.
Weather
Most staying dry by day, with plenty of cloud around but also brighter spells developing, most readily in the west. Generally light winds, though it may be gusty over the peaks in the morning.
Chance of cloud-free hill tops
80% in west 60% in east
Low cloud and visibility
Good or very good visibility, becoming poor within cloud which will be occasional between 500 and 900m, most frequently so in the east.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Generally dry by day with occasional brighter spells. Cloud thickening for the evening but staying dry. Fresh to strong summit winds developing by the evening.
Chance of cloud-free hill tops
80%.
Maximum wind speed expected
East or northeast mean 15-20mph with gusts reaching 40mph across most exposed ridges and summits in the afternoon or evening.
Temperature
- At 800m Minus 3 Celsius
- Valley Plus 2 Celsius increasing 6 Celsius for the afternoon
- Freezing level 500-600m
Low cloud and visibility
Good or very good visibility, becoming poor within cloud which will be occasional between 500m and 900m by day.
Mountain weather information
Tue 30 Dec
Sunrise:
Sunset:
Dry with brighter spells. Light summit winds. Freezing level 500-600m.
Wed 31 Dec
Sunrise:
Sunset:
Bright, dry start. Turning rather cloudy later with some chance of showers. Light summit winds. Freezing level 500-600m.
Thu 1 Jan
Sunrise:
Sunset:
Cloudy with some patchy light rain, wintry across higher peaks. Fresh to strong summit winds. Freezing level 400-600m, lifting to 800-1000m later in the day.
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.