Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High for relatively settled for Saturday, then very wet and windy for Sunday, but lowering for the detail of the worst conditions arriving later.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
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.
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
Largely dry with some brighter spells. Fresh to strong southwest summit winds.
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
20% | 10% | 10% | 10% | <05% | <05% |
Wind direction and speed (mph)
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
SW
31
|
SW
27
|
W
23
|
SW
21
|
SW
20
|
SW
23
|
| 600m |
SW
21
|
SW
18
|
SW
18
|
SW
17
|
SW
14
|
S
17
|
| 300m |
SW
13
|
SW
12
|
SW
13
|
SW
12
|
S
9
|
S
11
|
| Valley |
SW
13
|
SW
12
|
SW
13
|
W
12
|
S
9
|
S
12
|
Wind gust (mph)
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m | 38 | 34 | 30 | 29 | 26 | 29 |
| 600m | 26 | 25 | 25 | 24 | 19 | 23 |
| 300m | 22 | 22 | 23 | 22 | 18 | 21 |
| Valley | 22 | 21 | 22 | 21 | 18 | 22 |
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
3°
|
3°
|
3°
|
3°
|
3°
|
2°
|
| 600m |
5°
|
5°
|
6°
|
6°
|
5°
|
4°
|
| 300m |
7°
|
7°
|
8°
|
8°
|
7°
|
6°
|
| Valley |
8°
|
8°
|
10°
|
10°
|
8°
|
8°
|
| Freezing Level |
1,200m
|
1,200m
|
1,100m
|
1,200m
|
1,200m
|
1,200m
|
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
-4°
|
-4°
|
-3°
|
-3°
|
-3°
|
-4°
|
| 600m |
0°
|
0°
|
1°
|
1°
|
1°
|
0°
|
| 300m |
4°
|
4°
|
5°
|
5°
|
4°
|
3°
|
| Valley |
5°
|
6°
|
7°
|
7°
|
6°
|
4°
|
Additional weather information
Meteorologist's view
Severe wind chill effect confined to higher tops.
Weather
Widespread low cloud at first, leading to hill fog, this lifting and breaking to allow sunny spells to develop, along with perhaps a few afternoon showers. This evening areas of low cloud are likely to develop.
Chance of cloud-free hill tops
30% becoming 90% this afternoon, then 60% this evening.
Low cloud and visibility
Cloud bases generally around 800-900m this morning, but occasionally lowering 400-600m. This afternoon broken cloud lifts clear of most summits, only to return to 800-900m this evening. Very poor visibility within cloud, generally rather hazy below the cloud, temporarily decreasing to only near-by hills visible if any showers arrive.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
A dull day with periods of occasionally heavy rain arriving by mid-morning. The heavy rain becomes persistent through the afternoon and early evening. Rain clears to scattered showers late evening. Conditions hazardous by day with the combination of storm force winds, slippery ground due to the heavy rain and extensive hill fog.
Chance of cloud-free hill tops
Decreasing less than 10%.
Maximum wind speed expected
South increasing to mean 60-70mph from late morning, with gusts reaching 90-95mph across the most exposed ridges and summits.
Temperature
- At 800m Plus 3 increasing plus 6 Celsius
- Valley Plus 4 Celsius increasing 11 Celsius for the afternoon
- Freezing level Initially 1100m then increasing to above the summits
Low cloud and visibility
Moderate or poor in rain, very poor within cloud with bases extensive from 500m by day.
Mountain weather information
Mon 24 Feb
Sunrise:
Sunset:
Sunshine and scattered heavy showers, with a chance of hail and thunder. Strong southwest summit winds. Freezing level above all peaks.
Tue 25 Feb
Sunrise:
Sunset:
Brighter spells and showers, some turning heavy and across highest peaks wintry. Fresh or strong southwest summit winds. Freezing level around 1000m.
Wed 26 Feb
Sunrise:
Sunset:
Dry, sunny spells before becoming cloudy. Southwesterly summit winds increasing strong for the afternoon. Freezing level 800-1000m.
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.