Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
Generally high confidence for Wednesday and the start of Thursday. Confidence lowers on Thursday afternoon regarding the extent of snowfall due to uncertainties on the track of Storm Goretti.
This evening forecast
Cloud and rain, snow above 800m clearing this evening to leave clear spells and wintry showers. Strong winds with gales on summits and a bitter wind chill.
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
A cold day with mainly light snow showers. Summit gales and a bitter wind chill.
| 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) |
30% | 30% | 40% | 40% | 30% | 20% | 20% | 60% |
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 |
NW
38
|
NW
43
|
NW
44
|
NW
39
|
NW
36
|
NW
31
|
W
21
|
SW
12
|
| 600m |
NW
22
|
NW
28
|
NW
27
|
NW
25
|
NW
24
|
NW
20
|
W
13
|
SW
8
|
| 300m |
NW
13
|
NW
18
|
NW
17
|
NW
15
|
NW
16
|
NW
13
|
W
6
|
S
3
|
| Valley |
NW
13
|
NW
19
|
NW
18
|
NW
16
|
NW
17
|
NW
13
|
W
6
|
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 | 45 | 51 | 52 | 48 | 44 | 38 | 26 | 14 |
| 600m | 28 | 36 | 35 | 33 | 32 | 26 | 17 | 11 |
| 300m | 24 | 32 | 31 | 29 | 28 | 23 | 14 | 6 |
| Valley | 25 | 32 | 31 | 29 | 28 | 23 | 14 | 6 |
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
-2°
|
-3°
|
-3°
|
-4°
|
-3°
|
-3°
|
-2°
|
-2°
|
| 600m |
0°
|
-1°
|
-1°
|
-1°
|
0°
|
0°
|
0°
|
0°
|
| 300m |
2°
|
2°
|
2°
|
1°
|
2°
|
3°
|
2°
|
2°
|
| Valley |
4°
|
3°
|
3°
|
3°
|
4°
|
4°
|
3°
|
3°
|
| Freezing Level |
500m
|
400m
|
400m
|
300m
|
400m
|
400m
|
400m
|
500m
|
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
-12°
|
-13°
|
-14°
|
-14°
|
-13°
|
-12°
|
-10°
|
-8°
|
| 600m |
-7°
|
-8°
|
-9°
|
-8°
|
-8°
|
-6°
|
-5°
|
-4°
|
| 300m |
-3°
|
-4°
|
-4°
|
-4°
|
-3°
|
-2°
|
-1°
|
1°
|
| Valley |
-1°
|
-2°
|
-2°
|
-2°
|
-1°
|
0°
|
1°
|
2°
|
Additional weather information
Meteorologist's view
Another very cold day with an extreme wind chill on the upper mountain. Gusts to around 50mph around summit level in the morning will give challenging walking conditions with a significant risk of being blown over.
Weather
A bright day with sunny spells a few light snow showers in the morning, falling as rain below 300m. Generally drier in the afternoon but turning overcast in the evening with light rain. Strong northwesterly winds with gales on summits and a severe wind chill.
Chance of cloud-free hill tops
40% increasing to 60% in the afternoon. Decreasing to 20% in the evening.
Low cloud and visibility
Areas of cloud above 700m. Good visibility below cloud bases but poor in snow showers alongside some temporary lower bases. Low cloud becoming extensive in the evening.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
A mainly cloudy day with a few spots of light rain or hill snow above 600m, turning more persistent in the evening and falling as snow down to lower levels, this heavy for a time and with some drifting accumulations.
Chance of cloud-free hill tops
40% decreasing to 10%.
Maximum wind speed expected
Increasing to gusting 30-40mph on summits in the evening
Temperature
- At 800m Zero Celsius decreasing minus 2 Celsius.
- Valley Plus 3 Celsius decreasing 1 Celsius.
- Freezing level 700m decreasing to 300m later.
Low cloud and visibility
Patchy low cloud bases around 500-600m will become extensive and lower down to 300-400m during the afternoon. Visibility becoming a few kilometres below cloud bases but very poor in snow later.
Mountain weather information
Fri 9 Jan
Sunrise:
Sunset:
A cold day with a few showers to start but turning drier and brighter. Fresh to strong summit winds.
Sat 10 Jan
Sunrise:
Sunset:
A settled day with some sunny spells. Light to moderate winds.
Sun 11 Jan
Sunrise:
Sunset:
Turning unsettled and very windy with rain spreading in from the west.
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.