Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High confidence for a severely cold spell for Eryri for the first days of 2026, full winter conditions can be expected in the mountains. Uncertainties in amount of wintry showers and strength of wind details for each day.
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.
Mountain weather forecast
A very cold but dry day out on the mountains, with some bright or sunny 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
28
|
E
25
|
E
17
|
NE
17
|
NE
17
|
NE
15
|
| 600m |
E
14
|
E
11
|
NE
10
|
NE
9
|
NE
10
|
E
8
|
| 300m |
E
6
|
E
4
|
NE
4
|
NE
5
|
NE
7
|
E
5
|
| Valley |
E
6
|
E
4
|
NE
4
|
NE
5
|
NE
7
|
E
5
|
Wind gust (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 34 | 30 | 20 | 20 | 21 | 19 |
| 600m | 21 | 17 | 13 | 12 | 14 | 12 |
| 300m | 15 | 13 | 8 | 11 | 13 | 11 |
| Valley | 15 | 13 | 8 | 10 | 13 | 10 |
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-2°
|
-1°
|
-2°
|
-2°
|
-2°
|
-2°
|
| 600m |
1°
|
1°
|
1°
|
1°
|
0°
|
0°
|
| 300m |
3°
|
3°
|
4°
|
3°
|
2°
|
2°
|
| Valley |
4°
|
4°
|
5°
|
5°
|
4°
|
3°
|
| Freezing Level |
600m
|
500m
|
500m
|
500m
|
400m
|
400m
|
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-10°
|
-9°
|
-8°
|
-8°
|
-9°
|
-9°
|
| 600m |
-4°
|
-4°
|
-4°
|
-3°
|
-4°
|
-4°
|
| 300m |
0°
|
1°
|
2°
|
1°
|
0°
|
0°
|
| Valley |
2°
|
2°
|
3°
|
3°
|
1°
|
1°
|
Additional weather information
Meteorologist's view
The main hazard on the mountains will be the effects of the cold at height, resulting in wind-chill. Prepare for very cold conditions.
Weather
A sharp frost at first, but then a dry and bright day with sunny spells. Feeling very cold with the sunshine adding very little warmth, a severe wind-chill is expected. Very cold overnight with widespread frost.
Chance of cloud-free hill tops
95%, a few early morning patches of cloud.
Low cloud and visibility
Any cloud will be well above summits leaving a clear day with far reaching views from the hills, visibility will be good to very good.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Another cold and dry day with severe wind-chill and a good deal of sunshine. Cloud building in the afternoon and evening with snow possible overnight.
Chance of cloud-free hill tops
80% some cloud forming around the tops in the afternoon.
Maximum wind speed expected
Westerly to northwesterly 15-20mph with gusts 30-35mph.
Temperature
- At 800m Minus 4 rising to Minus 2 Celsius.
- Valley Plus 1 rising to Plus 3 Celsius.
- Freezing level 100-200m rising to 500m.
Low cloud and visibility
Cloud mostly above the summits in the morning but patchy or scattered low cloud will form in the afternoon near mountain tops, reducing visibility for a time.
Mountain weather information
Thu 1 Jan
Sunrise:
Sunset:
A bitterly cold day with strong northwesterly winds, some wintry showers are possible but also some brighter spells. Snow accumulations are likely at higher levels. Freezing level 500m
Fri 2 Jan
Sunrise:
Sunset:
Remaining very cold with some wintry showers and sunny spells. A severe wind-chill is expected in strong northwesterly winds. Freezing level 200-300m.
Sat 3 Jan
Sunrise:
Sunset:
Freezing conditions continue with severe wind-chill in the fresh northerly winds, and a continued risk of wintry showers. Ground is expected to be frozen at all elevations.
Updated at:
Summit specific forecast
Mountain summit forecast map
Loading map…
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.