Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High for the mobile nature of the westerly weather patterns, but lowering for the transitional timing detail.
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
Snow and rain, generally patchy and light. Summit winds strong at first.
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
90% | 60% | 20% | 20% | 10% | 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 |
N
27
|
N
20
|
N
13
|
N
12
|
N
8
|
NE
4
|
| 600m |
N
14
|
N
12
|
N
10
|
N
9
|
N
5
|
N
2
|
| 300m |
N
9
|
N
10
|
N
9
|
N
8
|
N
4
|
S
2
|
| Valley |
N
9
|
N
10
|
N
9
|
N
8
|
N
4
|
SW
1
|
Wind gust (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 35 | 28 | 19 | 17 | 13 | 5 |
| 600m | 19 | 18 | 15 | 13 | 9 | 4 |
| 300m | 18 | 18 | 15 | 13 | 8 | 3 |
| Valley | 18 | 18 | 15 | 13 | 8 | 3 |
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-1°
|
-1°
|
0°
|
0°
|
-1°
|
0°
|
| 600m |
1°
|
1°
|
2°
|
2°
|
1°
|
1°
|
| 300m |
3°
|
3°
|
4°
|
5°
|
4°
|
3°
|
| Valley |
5°
|
5°
|
5°
|
6°
|
5°
|
4°
|
| Freezing Level |
700m
|
700m
|
800m
|
800m
|
700m
|
900m
|
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-10°
|
-8°
|
-6°
|
-6°
|
-5°
|
-2°
|
| 600m |
-5°
|
-4°
|
-3°
|
-2°
|
-1°
|
0°
|
| 300m |
0°
|
-1°
|
0°
|
2°
|
2°
|
1°
|
| Valley |
2°
|
1°
|
2°
|
3°
|
4°
|
3°
|
Additional weather information
Meteorologist's view
Severe wind chill effect extended down to mid-levels during the morning.
Weather
Overcast with periods of rain, falling as sleet or snow initially above around 500 metres. rain then patchy through the morning and becoming mostly dry through the afternoon and evening.
Chance of cloud-free hill tops
10% becoming 40% from late morning then 60% through the afternoon
Low cloud and visibility
Good or very good becoming moderate or poor in rain, very poor in sleet or snow and within cloud, which will be extensive from 500m early morning, occasionally so thereafter.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
A rather cloudy day. Largely dry for the morning, then patchy rain increasingly reaching from the south through the afternoon and evening. Moderate winds.
Chance of cloud-free hill tops
50% by day
Maximum wind speed expected
South or southeast 15-20mph
Temperature
- At 800m Zero Celsius increasing 4 Celsius for the afternoon
- Valley Plus 1 Celsius increasing 12 Celsius for the afternoon
- Freezing level 800m at dawn, soon lifting above summits during the morning
Low cloud and visibility
Good or very good becoming moderate or poor in rain, very poor within cloud, which occasionally lowers 600m by day.
Mountain weather information
Sun 8 Mar
Sunrise:
Sunset:
Rather cloudy with some patchy light rain. Fresh winds. Freezing level above summits.
Mon 9 Mar
Sunrise:
Sunset:
Cloudy with occasional rain, though most of this should be light and a chance of some brighter spells later in the day. Light winds. Freezing level above summits.
Tue 10 Mar
Sunrise:
Sunset:
Cloudy with occasional rain, turning heavier later in the day. Summit gales. Freezing level above summits.
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.