Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High for generally east to southeast flow persisting also for relatively unsettled weather, but lowering confidence for timing detail of worst of conditions.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
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.
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.
Blizzards
Blizzards and whiteouts present challenging and serious conditions due to a combination of falling or blowing snow, strong winds and cold temperatures. They can be highly disorientating, often resulting in near-zero visibility with limited or no visual references and no distinction between ground and sky. Cliff edges and cornices may not be apparent, even close up. These conditions require very good navigational skills.
Storm Force Winds
Storm force winds (gusts over 70mph) make walking very strenuous with any mobility virtually impossible over exposed ground. Where these conditions occur there is a high risk of being blown over and even standing may be impossible at times with a risk of being blown off one’s feet. Basic tasks such as using a map, eating, putting on extra clothing or communication become extremely difficult away from any shelter.
Mountain weather forecast
Occasional snow and rain, most likely this afternoon and evening. Gale to severe gale summit winds.
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
30% | 30% | 30% | 40% | 60% | 70% |
Wind direction and speed (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
SE
45
|
SE
45
|
SE
45
|
SE
46
|
SE
46
|
SE
43
|
| 600m |
SE
31
|
SE
31
|
SE
32
|
SE
34
|
SE
33
|
SE
32
|
| 300m |
SE
22
|
SE
22
|
SE
23
|
SE
25
|
SE
24
|
SE
24
|
| Valley |
SE
22
|
SE
22
|
SE
23
|
SE
25
|
SE
24
|
SE
24
|
Wind gust (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 54 | 55 | 56 | 57 | 57 | 54 |
| 600m | 39 | 41 | 41 | 45 | 44 | 43 |
| 300m | 38 | 38 | 39 | 42 | 42 | 40 |
| Valley | 37 | 38 | 38 | 41 | 41 | 41 |
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
0°
|
0°
|
0°
|
0°
|
0°
|
0°
|
| 600m |
2°
|
2°
|
3°
|
3°
|
2°
|
3°
|
| 300m |
5°
|
5°
|
6°
|
6°
|
5°
|
5°
|
| Valley |
6°
|
6°
|
7°
|
7°
|
6°
|
7°
|
| Freezing Level |
900m
|
900m
|
900m
|
1,000m
|
900m
|
1,000m
|
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-9°
|
-10°
|
-9°
|
-9°
|
-10°
|
-9°
|
| 600m |
-5°
|
-5°
|
-4°
|
-4°
|
-5°
|
-5°
|
| 300m |
0°
|
0°
|
0°
|
0°
|
-1°
|
0°
|
| Valley |
2°
|
2°
|
2°
|
3°
|
2°
|
2°
|
Additional weather information
Meteorologist's view
Conditions becoming potentially hazardous this afternoon as hill fog, summit snow and the chance of storm force winds increase. Severe wind chill effect extending down to mid-levels. Wind speeds above should be 10-15mph higher than the figures stated for the highest summits.
Weather
Cloudy to overcast with hill fog becoming widespread. Outbreaks of rain, falling as snow above approximately 700m until late evening then rising to around 900m, light until this evening then turning heavier and more persistent. The rain or snow is most likely across southern areas.
Chance of cloud-free hill tops
40% becoming 20% later.
Low cloud and visibility
Good or very good with distant hills visible, becoming moderate or poor in rain, very poor in snow and within cloud with bases becoming quite extensive from 600m rom mid-afternoon.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Cloudy with occasional rain, snow above 900m. Outbreaks generally light, but possibly heavy at first. Fresh to strong summit winds.
Chance of cloud-free hill tops
20%
Maximum wind speed expected
Southeast mean 30-35mph with gusts reaching 45-55mph across exposed ridges and summits.
Temperature
- At 800m Plus 1-2 Celsius
- Valley Plus 5 Celsius increasing 8 Celsius during the afternoon
- Freezing level 900m
Low cloud and visibility
Good or very good, becoming moderate or poor in rain, very poor in snow and within cloud with bases quite extensive from 500m.
Mountain weather information
Mon 26 Jan
Sunrise:
Sunset:
Rather cloudy with some early patchy rain and summit snow for the morning, then probably drier for a time before rain and summit snow arrives later. Snow level around 700m. Southeast summit winds increasing strong later in the day.
Tue 27 Jan
Sunrise:
Sunset:
Overcast with periods of snow and rain, that turns heavier at times. Snow level lowering to around 500-600m. Summit wind increasing gale to severe gale east to southeast with a risk of storm force winds.
Wed 28 Jan
Sunrise:
Sunset:
Unsettled with showers or longer periods of rain and snow, turning heavy at times. Southeast summit winds easing.
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.