Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High for the general weather story with cold conditions giving way to very unsettled and milder weather through the weekend. Lower for the details of the change on Saturday.
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.
Thunderstorms
Lightning is a significant mountain hazard which can result in serious injury or death. Mountain terrain often leaves one highly exposed to lightning strikes. Hail may give unpleasant conditions with torrential rain and localised flash flooding also possible, mainly in Summer months.
Mountain weather forecast
Mainly cloudy with scattered snow showers. Very cold. Windy later.
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
20% | 20% | 20% | 30% | 40% | 60% |
Wind direction and speed (mph)
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
E
12
|
E
13
|
N
13
|
NW
17
|
NW
27
|
NW
36
|
| 600m |
E
11
|
E
8
|
N
8
|
NW
11
|
W
16
|
NW
24
|
| 300m |
E
7
|
E
3
|
N
5
|
NW
7
|
W
8
|
NW
15
|
| Valley |
SE
7
|
E
3
|
N
5
|
NW
7
|
W
9
|
NW
16
|
Wind gust (mph)
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m | 15 | 16 | 16 | 21 | 33 | 45 |
| 600m | 14 | 12 | 11 | 15 | 22 | 34 |
| 300m | 13 | 9 | 9 | 12 | 17 | 29 |
| Valley | 13 | 9 | 9 | 13 | 18 | 30 |
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
-3°
|
-3°
|
-4°
|
-4°
|
-4°
|
-3°
|
| 600m |
-1°
|
-1°
|
-1°
|
-2°
|
-2°
|
-1°
|
| 300m |
1°
|
1°
|
1°
|
1°
|
0°
|
1°
|
| Valley |
2°
|
2°
|
2°
|
2°
|
2°
|
3°
|
| Freezing Level |
100m
|
100m
|
300m
|
300m
|
200m
|
300m
|
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
-9°
|
-9°
|
-10°
|
-11°
|
-13°
|
-13°
|
| 600m |
-6°
|
-5°
|
-6°
|
-7°
|
-8°
|
-8°
|
| 300m |
-3°
|
-1°
|
-1°
|
-3°
|
-4°
|
-4°
|
| Valley |
-2°
|
0°
|
0°
|
-1°
|
-2°
|
-2°
|
Additional weather information
Meteorologist's view
Bitterly cold. Note the more widespread snow showers and stronger winds developing later in the day, especially evening.
Weather
Some sunny spells at first, becoming cloudy during the day with some light snow showers, mainly in the north, becoming more widespread late afternoon. During the evening the snow showers will become heavier and more widespread and accompanied by strong northwesterly winds, perhaps touching gale force on the higher summits. The odd thundery shower is possible from late afternoon.
Chance of cloud-free hill tops
80%, becoming 60% in the afternoon and 30% in the evening.
Low cloud and visibility
Generally excellent visibility away from showers with clear views of distant hills. Locally poor or very poor in snow showers with occasional cloud above 500-600m. Becoming very poor for longer periods in the evening with cloud base reducing to 400m.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
A mixture of clear or bright spells and occasional snow showers, these turning more to a rain/sleet mix later, below 600m. The showers will ease during the afternoon and evening. Still feeling very cold with a severe wind chill on the tops.
Chance of cloud-free hill tops
60%.
Maximum wind speed expected
West or northwest 25-35 mph gusting 40-50 mph, decreasing 10-15mph.
Temperature
- At 800m Minus 2C rising to ZeroC.
- Valley Minus 2C rising to Plus 3C.
- Freezing level 200-300m rising to 600-700m.
Low cloud and visibility
Mainly excellent visibility between showers. Occasionally poor or very poor in sleet or snow showers with areas of cloud above 500-600m.
Mountain weather information
Sat 23 Nov
Sunrise:
Sunset:
Heavy rain will arrive by morning, with a brief period of snow above 600m. Rain will persist for most of the day with flooding possible. Severe gale or storm force southerly winds. Freezing level 600m rising above summits in the morning.
Sun 24 Nov
Sunrise:
Sunset:
Heavy rain clearing by morning then bright spells and occasional rain showers. Very windy with southerly gales or perhaps storm force winds. Freezing level above summits.
Mon 25 Nov
Sunrise:
Sunset:
Very unsettled with showers or longer spells of rain moving in from the west. Strong to gale force westerly winds. Freezing level lowering to 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.