Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High for snow showers easing through the day and for a change to slightly milder conditions through the middle of the week, but low from later Thursday due to uncertainties over the track of a potentially deep area of low pressure, currently expected to move east across the southern United Kingdom.
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.
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
Sunny spells and snow showers. Bitterly cold, but winds easing
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
40% | 30% | 30% | 20% | 20% | 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 |
NW
26
|
N
29
|
N
26
|
N
22
|
N
23
|
N
16
|
| 600m |
NW
18
|
N
12
|
N
16
|
N
14
|
N
11
|
NE
8
|
| 300m |
NW
11
|
NW
6
|
N
10
|
N
8
|
N
6
|
SW
3
|
| Valley |
NW
11
|
NW
6
|
N
10
|
N
8
|
N
7
|
SW
4
|
Wind gust (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 31 | 34 | 32 | 28 | 28 | 20 |
| 600m | 22 | 17 | 22 | 19 | 17 | 11 |
| 300m | 19 | 16 | 19 | 17 | 16 | 8 |
| Valley | 19 | 16 | 19 | 16 | 16 | 8 |
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-5°
|
-5°
|
-5°
|
-4°
|
-5°
|
-5°
|
| 600m |
-3°
|
-3°
|
-2°
|
-2°
|
-3°
|
-3°
|
| 300m |
-1°
|
-1°
|
1°
|
0°
|
-1°
|
-2°
|
| Valley |
0°
|
1°
|
2°
|
2°
|
1°
|
0°
|
| Freezing Level |
0m
|
0m
|
100m
|
100m
|
100m
|
0m
|
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-14°
|
-14°
|
-13°
|
-13°
|
-14°
|
-12°
|
| 600m |
-10°
|
-8°
|
-8°
|
-8°
|
-8°
|
-8°
|
| 300m |
-6°
|
-4°
|
-4°
|
-4°
|
-4°
|
-4°
|
| Valley |
-5°
|
-3°
|
-2°
|
-2°
|
-2°
|
-2°
|
Additional weather information
Meteorologist's view
Bitterly cold at despite some sunny spells and easing winds with warm, waterproof clothing essential. Surfaces frozen at most levels.
Weather
Snow showers through the morning with some sunny spells, the showers becoming more isolated through the afternoon and then die out through the evening, It will remain very cold with frozen surfaces at all levels.
Chance of cloud-free hill tops
Around 60%, improving through the afternoon
Low cloud and visibility
Occasional, especially through the morning, periods of cloud above 600m expected below the summits. Away from any cloud visibility excellent with good panoramic views of surrounding mountains, but around a kilometre in any snow showers.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Cloud increases overnight with outbreaks of snow spreading east, the snow gradually turning to sleet or rain below about 600m through the morning before becoming patchier through the middle of the day. More persistent rain, sleet and snow (above 750m) will spread east through the late afternoon and early evening.
Chance of cloud-free hill tops
Around 40% improving to 75% for a time in afternoon then falling close to zero from late afternoon.
Maximum wind speed expected
Westerly 15mph increasing 25-30mph, with gusts around 50mph over higher ridges and summits, by early afternoon
Temperature
- At 800m Around minus 5 Celsius rising to Zero by early afternoon
- Valley Around minus 2 Celsius through the early hours rising to plus 4 Celsius by day
- Freezing level Less than 300m, rising to around 900m in the afternoon.
Low cloud and visibility
Occasional or periods of cloud developing above 450-600m by dawn, becoming more occasional above 600-750m for a time through the middle of the day, then becoming more persistent above 450-600m from late afternoon. Away from cloud visibility good falling to several kilometres in rain and sleet and around a kilometre in snow.
Mountain weather information
Wed 7 Jan
Sunrise:
Sunset:
Dry with long clear or sunny spells but outbreaks of rain, sleet and snow spreading east from late afternoon. Fresh northwesterly winds becoming more westerly. Freezing level rising to 750m.
Thu 8 Jan
Sunrise:
Sunset:
Overnight rain, sleet and snow clearing to leave sunny spells but cloud and outbreaks of rain, sleet and snow edging north later. Westerly winds easing, turning easterly later. Freezing level round 600m.
Fri 9 Jan
Sunrise:
Sunset:
Low confidence, sunny spells and occasional wintry showers expected with winds turning more northwesterly. However small risk of very windy conditions with heavy rain, sleet and summit snow.
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.