Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High
This evening forecast
Patchy cloud and scattered or isolated showers.
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.
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 and bright start. Summit gales and rain later.
| 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) |
<05% | <05% | <05% | <05% | <05% | 10% | 30% | 50% |
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 |
SW
26
|
SW
27
|
SW
28
|
SW
34
|
SW
43
|
SW
47
|
SW
48
|
SW
52
|
| 600m |
SW
16
|
SW
16
|
S
17
|
S
23
|
SW
29
|
SW
31
|
S
33
|
SW
35
|
| 300m |
SW
9
|
SW
9
|
S
9
|
S
13
|
S
18
|
SW
20
|
S
21
|
S
22
|
| Valley |
SW
9
|
SW
9
|
S
9
|
S
13
|
S
18
|
SW
20
|
S
21
|
S
23
|
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 | 31 | 33 | 33 | 41 | 53 | 58 | 59 | 65 |
| 600m | 21 | 22 | 22 | 29 | 38 | 42 | 43 | 46 |
| 300m | 19 | 20 | 19 | 25 | 32 | 36 | 38 | 40 |
| Valley | 19 | 20 | 19 | 25 | 31 | 36 | 38 | 41 |
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
2°
|
2°
|
2°
|
3°
|
3°
|
3°
|
3°
|
3°
|
| 600m |
5°
|
5°
|
5°
|
5°
|
5°
|
5°
|
5°
|
5°
|
| 300m |
6°
|
6°
|
6°
|
7°
|
7°
|
8°
|
8°
|
8°
|
| Valley |
7°
|
7°
|
7°
|
8°
|
9°
|
9°
|
9°
|
9°
|
| Freezing Level |
1,100m
|
1,000m
|
1,100m
|
1,100m
|
1,200m
|
1,200m
|
1,700m
|
2,300m
|
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
-4°
|
-4°
|
-4°
|
-5°
|
-5°
|
-6°
|
-5°
|
-5°
|
| 600m |
0°
|
0°
|
0°
|
-1°
|
-1°
|
-1°
|
-1°
|
-1°
|
| 300m |
4°
|
3°
|
3°
|
3°
|
3°
|
4°
|
3°
|
3°
|
| Valley |
5°
|
4°
|
4°
|
4°
|
5°
|
6°
|
5°
|
5°
|
Additional weather information
Meteorologist's view
Nothing further to add.
Weather
Occasional or patchy summit cloud overnight and early morning, then dry and bright during daylight hours with some sunny spells. Isolated light showers, then patchy rain in the evening. Strengthening southwest winds, summit gales developing.
Chance of cloud-free hill tops
40% overnight, then 60% daylight hours, falling 30% in the evening.
Low cloud and visibility
Occasional or patchy low cloud around the summits overnight and early morning, then mainly nil significant daylight hours, becoming extensive and lowering 600m or less in the evening. Visibility mostly good or very good during daylight hours, but poor or very poor in summit cloud and more generally in the evening in rain and lowering cloud.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
A poor day expected with outbreaks of rain and drizzle, heavy and persistent at times. Gale force summit winds and navigational difficulties.
Chance of cloud-free hill tops
30%
Maximum wind speed expected
Southwest 35 to 45mph gusting 60 to 70mph.
Temperature
- At 800m Plus 4 to 6 Celsius.
- Valley Plus 8 to 11 Celsius.
- Freezing level Above the summits.
Low cloud and visibility
Extensive low cloud, base 400 to 700m. Visibility moderate to very poor.
Mountain weather information
Mon 15 Dec
Sunrise:
Sunset:
Another wet day with a risk of flooding along with navigational difficulties. Winds from the south or southwest and strong to gale force over the summits. Extensive low cloud and poor or very poor visibility at times. Turning drier with easing winds and lifting cloud later in the day.
Tue 16 Dec
Sunrise:
Sunset:
Mainly dry with bright or clear spells. Light or moderate west or northwest winds at height. Freezing level near or above the summits.
Wed 17 Dec
Sunrise:
Sunset:
Dry overnight. Otherwise cloudy with outbreaks of rain, heavy and persistent at times. South or southwest winds strong to gale force at height.
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.