Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High for a largely fine, cold but breezy day Saturday and for an easterly or southeasterly airstream becoming established across the United Kingdom, but lower for cloud amounts and rainfall details from Sunday.
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
Dry with, especially in northwest, sunny spells. Strengthening southeasterly winds
| 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% | 10% |
Wind direction and speed (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
S
40
|
SE
46
|
SE
39
|
SE
38
|
SE
43
|
SE
42
|
| 600m |
S
28
|
S
32
|
SE
29
|
SE
28
|
SE
29
|
SE
29
|
| 300m |
S
17
|
SE
22
|
SE
20
|
SE
20
|
SE
20
|
SE
22
|
| Valley |
S
17
|
SE
23
|
SE
21
|
SE
20
|
SE
21
|
SE
23
|
Wind gust (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 46 | 54 | 48 | 48 | 53 | 53 |
| 600m | 34 | 40 | 38 | 37 | 40 | 39 |
| 300m | 30 | 37 | 34 | 34 | 37 | 38 |
| Valley | 30 | 37 | 34 | 34 | 37 | 39 |
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
2°
|
1°
|
1°
|
1°
|
0°
|
0°
|
| 600m |
4°
|
4°
|
4°
|
4°
|
3°
|
3°
|
| 300m |
6°
|
6°
|
6°
|
6°
|
5°
|
5°
|
| Valley |
7°
|
7°
|
8°
|
8°
|
6°
|
7°
|
| Freezing Level |
1,100m
|
1,100m
|
1,000m
|
900m
|
800m
|
1,100m
|
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-7°
|
-8°
|
-7°
|
-7°
|
-9°
|
-8°
|
| 600m |
-2°
|
-3°
|
-3°
|
-3°
|
-4°
|
-4°
|
| 300m |
2°
|
1°
|
2°
|
2°
|
0°
|
0°
|
| Valley |
3°
|
2°
|
4°
|
3°
|
2°
|
2°
|
Additional weather information
Meteorologist's view
Feeling cold in the strong southeasterly winds, gusts around 60mph over ridges and summits.
Weather
Early low cloud and mist slowly lifting to leave a largely dry and bright day, with sunny spells. Cloud increases from the west through the evening, with a band of rain, locally heavy, arriving towards midnight.
Chance of cloud-free hill tops
Around 90% in northwest but nearer 60% in south and east. Chances fall through the evening.
Low cloud and visibility
Occasional or periods of cloud above about 600-750m across southern and eastern hills, with little cloud below the summits for northwestern hills, cloud becoming more extensive, especially across the south and east through the evening. Away from cloud visibility very good or excellent with good panoramic views of surrounding mountains, perhaps falling to several kilometres in evening rain and drizzle.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Mostly cloudy overnight with outbreaks of mainly light rain. The rain clears eastwards soon after dawn but eastern hills continue cloudy with outbreaks of mainly light rain through the day, while western hills look dry with some sunny spells. Risk of more persistent rain in evening
Chance of cloud-free hill tops
Around 60% in the west but nearer 25% in the east.
Maximum wind speed expected
Southeasterly 25-30mph, gusts around 50mph over ridges and summits, gradually backing easterly 20mph.
Temperature
- At 800m Around plus 2 Celsius at first rising to plus 5 Celsius
- Valley Around plus 4 or 5 Celsius at dawn rising to plus 8 or 9 Celsius by day
- Freezing level Above the summits
Low cloud and visibility
Periods or persistent cloud above about 450-600m in the east, but more occasional at times above 600-750m in the west. Away from cloud visibility very good falling to several kilometres in rain.
Mountain weather information
Mon 22 Dec
Sunrise:
Sunset:
A cloudy day with outbreaks of rain, best of any brighter spells in the west. Occasionally strong easterly winds. Freezing level above summits
Tue 23 Dec
Sunrise:
Sunset:
Mostly cloudy, some brighter spells in west, with patchy rain, drizzle and summit snow. Occasionally strong easterly winds. Freezing level falling to 900m.
Wed 24 Dec
Sunrise:
Sunset:
Cloudy morning with patchy rain, drizzle and summit snow, but drier and, especially in west, brighter in afternoon. Occasionally strong easterly winds. Freezing level around 900m.
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.