Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High for cold northwesterly flow being replaced by a mild and wet westerly from Saturday, but lowering for the detail of transition also for the further change to showers then gradually colder conditions through the week to come.
This evening forecast
Rather cloudy with frequent wintry showers. Northwest summit gales and sub-zero temperatures bringing a very severe wind chill.
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.
Mountain weather forecast
Cold. Mainly cloudy with occasional wintry outbreaks. Severe wind chill despite the strong summit winds slowly easing.
| 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
|
|
Chance of precipitation (at 800m) |
70% | 80% | 70% | 60% | 60% | 30% | 20% | 10% |
Wind direction and speed (mph)
Altitude above mean sea level
| 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|---|---|
| 900m |
NW
35
|
W
38
|
W
32
|
W
25
|
NW
23
|
W
20
|
W
15
|
S
11
|
| 600m |
NW
25
|
NW
26
|
NW
22
|
W
16
|
NW
16
|
W
12
|
W
7
|
S
9
|
| 300m |
NW
16
|
W
19
|
W
15
|
W
10
|
NW
11
|
W
7
|
SW
3
|
S
5
|
| Valley |
NW
17
|
W
20
|
W
16
|
W
11
|
NW
12
|
W
7
|
S
4
|
S
7
|
Wind gust (mph)
Altitude above mean sea level
| 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|---|---|
| 900m | 44 | 48 | 40 | 31 | 30 | 25 | 18 | 14 |
| 600m | 34 | 36 | 30 | 23 | 22 | 17 | 11 | 12 |
| 300m | 29 | 33 | 26 | 20 | 20 | 13 | 6 | 9 |
| Valley | 30 | 34 | 28 | 21 | 20 | 14 | 7 | 11 |
Altitude above mean sea level
| 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|---|---|
| 900m |
-3°
|
-3°
|
-3°
|
-3°
|
-2°
|
-2°
|
-2°
|
-2°
|
| 600m |
-1°
|
-1°
|
0°
|
0°
|
0°
|
0°
|
0°
|
0°
|
| 300m |
1°
|
2°
|
2°
|
2°
|
3°
|
2°
|
2°
|
1°
|
| Valley |
3°
|
3°
|
3°
|
3°
|
4°
|
4°
|
3°
|
3°
|
| Freezing Level |
400m
|
400m
|
400m
|
500m
|
600m
|
600m
|
500m
|
600m
|
Altitude above mean sea level
| 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|---|---|
| 900m |
-13°
|
-13°
|
-12°
|
-10°
|
-9°
|
-9°
|
-8°
|
-8°
|
| 600m |
-8°
|
-9°
|
-7°
|
-6°
|
-5°
|
-4°
|
-4°
|
-4°
|
| 300m |
-4°
|
-4°
|
-4°
|
-3°
|
-1°
|
0°
|
0°
|
-1°
|
| Valley |
-2°
|
-2°
|
-2°
|
-1°
|
0°
|
1°
|
1°
|
0°
|
Additional weather information
Meteorologist's view
Cold with temperatures minus 2C at first around the foothills and a significant wind chill throughout.
Weather
Rather cloudy throughout with occasional outbreaks of snow and sleet, perhaps rain at lowest levels. Best chance of catchy the limited weak sunshine will be during the morning.
Chance of cloud-free hill tops
30%
Low cloud and visibility
Very good visibility becoming poor in snow, very poor within cloud with bases quite frequently lowering 600m.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
An overcast start to the day with periods of occasionally heavy snow that turns to rain before mid-morning. Rain becoming patchy for the afternoon. Conditions hazardous at first in snow, hill fog and severe summit gales.
Chance of cloud-free hill tops
10%
Maximum wind speed expected
South to southeast veering southwest later in day, mean 40-50mph with gusts reaching 60-70mph across more exposed ridges and summits, before easing gradually from early afternoon
Temperature
- At 800m Minus 1 Celsius increasing plus 8 Celsius by early evening
- Valley Minus 3 Celsius increasing 11 Celsius by afternoon
- Freezing level 500m increasing above all summits from mid-day
Low cloud and visibility
Good visibility becoming moderate in rain, poor in snow, very poor within cloud with bases extensive from 500m with patches lower down for southern and western aspects
Mountain weather information
Sun 24 Nov
Sunrise:
Sunset:
Cloudy with periods of rain early in the day, clearing to leave brighter spells and only a few isolated light showers for the afternoon. Freezing level above all peaks. Strong to gale summit winds.
Mon 25 Nov
Sunrise:
Sunset:
Showers brought on fresh to strong west to southwest winds. Freezing level remaining above all peaks.
Tue 26 Nov
Sunrise:
Sunset:
Moderate westerly summit winds bringing scattered showers that turn wintry across higher peaks.
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.