Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High confidence for unsettled start, lowering for the timing and extent of precipitation from Wednesday.
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.
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.
Mountain weather forecast
Showers. Rather cloudy. Strong summit winds.
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
40% | 80% | 40% | 40% | 20% | 20% |
Wind direction and speed (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
W
34
|
W
35
|
W
32
|
W
33
|
NW
31
|
NW
33
|
| 600m |
W
22
|
W
23
|
W
22
|
W
23
|
NW
20
|
NW
20
|
| 300m |
W
14
|
W
15
|
W
16
|
NW
16
|
NW
13
|
NW
13
|
| Valley |
W
14
|
W
14
|
W
16
|
W
16
|
NW
13
|
NW
13
|
Wind gust (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 40 | 41 | 39 | 41 | 38 | 41 |
| 600m | 27 | 29 | 29 | 31 | 26 | 28 |
| 300m | 24 | 26 | 27 | 28 | 24 | 25 |
| Valley | 24 | 26 | 27 | 28 | 24 | 25 |
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-1°
|
-1°
|
-1°
|
0°
|
-1°
|
-2°
|
| 600m |
1°
|
1°
|
2°
|
2°
|
2°
|
0°
|
| 300m |
4°
|
4°
|
4°
|
5°
|
4°
|
2°
|
| Valley |
5°
|
5°
|
6°
|
7°
|
6°
|
4°
|
| Freezing Level |
700m
|
800m
|
800m
|
900m
|
700m
|
400m
|
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-10°
|
-10°
|
-9°
|
-8°
|
-10°
|
-12°
|
| 600m |
-6°
|
-5°
|
-5°
|
-4°
|
-5°
|
-6°
|
| 300m |
-1°
|
-1°
|
-1°
|
0°
|
0°
|
-2°
|
| Valley |
1°
|
1°
|
1°
|
2°
|
2°
|
0°
|
Additional weather information
Meteorologist's view
Winds 10-15mph stronger than the speeds above across most exposed ridges and summits. Very difficult conditions during the morning at height in quite extensive cloud shrouding summits, driving snow and a severe wind chill.
Weather
A rather cloudy day with showers with a snow level around 600-700m. Showers frequent and occasionally heavy for the morning, before easing through the afternoon as a few brighter spells develop.
Chance of cloud-free hill tops
30% becoming 60% late afternoon
Low cloud and visibility
Visibility becoming poor in rain showers, very poor in snow showers and within cloud with bases quite extensive from 500m at first, before lifting and breaking later in the day.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Dry with sunshine for the morning, waning to brighter spells for the afternoon as higher cloud spreads in. Fresh summit winds easing for the afternoon.
Chance of cloud-free hill tops
90% plus
Maximum wind speed expected
North or northwest beginning 20-25mph with gusts reaching 35mph across more exposed ridges and summits, gradually easing from late morning.
Temperature
- At 800m Minus 3 Celsius
- Valley Plus 1 Celsius increasing 7 Celsius during the afternoon
- Freezing level 300-500m
Low cloud and visibility
Visibility very good or excellent.
Mountain weather information
Wed 18 Feb
Sunrise:
Sunset:
Dry start then increasing chance of snow and low level rain reaching from the south into the afternoon and evening. Freezing level 400 m falling to low levels. East to southeast summit gales developing.
Thu 19 Feb
Sunrise:
Sunset:
Some chance of early patchy snow and rain, but otherwise dry with bright and sunny spells increasing for the afternoon. Freezing level lifting to around 600m. Strong summit winds.
Fri 20 Feb
Sunrise:
Sunset:
Showers or longer periods of rain and initially summit snow. Freezing level rising above summits. Gale, perhaps storm, force summit winds.
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.