Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High confidence for an unsettled, windy and rather cold spell with weather fronts moving in from the Atlantic, but some uncertainty in the timings. Saturday looks the most promising day for drier and brighter weather.
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.
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.
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.
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
Sunny spells and wintry showers. Strong winds slowly easing. Cold.
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
30% | 30% | 30% | 50% | 70% | 30% |
Wind direction and speed (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
SW
47
|
SW
40
|
SW
38
|
SW
33
|
W
22
|
NW
24
|
| 600m |
SW
33
|
SW
29
|
SW
27
|
SW
24
|
W
14
|
W
12
|
| 300m |
SW
19
|
SW
19
|
SW
18
|
SW
16
|
W
9
|
NW
6
|
| Valley |
SW
19
|
SW
18
|
SW
18
|
SW
16
|
W
9
|
NW
6
|
Wind gust (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 55 | 48 | 46 | 40 | 27 | 28 |
| 600m | 40 | 36 | 34 | 30 | 18 | 17 |
| 300m | 33 | 31 | 30 | 27 | 17 | 13 |
| Valley | 32 | 31 | 31 | 27 | 17 | 13 |
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-4°
|
-3°
|
-2°
|
-2°
|
-2°
|
-2°
|
| 600m |
-1°
|
0°
|
1°
|
1°
|
0°
|
1°
|
| 300m |
2°
|
3°
|
4°
|
3°
|
3°
|
3°
|
| Valley |
4°
|
4°
|
5°
|
5°
|
4°
|
4°
|
| Freezing Level |
400m
|
500m
|
500m
|
600m
|
600m
|
600m
|
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-15°
|
-13°
|
-12°
|
-11°
|
-9°
|
-9°
|
| 600m |
-9°
|
-8°
|
-6°
|
-6°
|
-5°
|
-4°
|
| 300m |
-4°
|
-2°
|
-1°
|
-2°
|
-1°
|
0°
|
| Valley |
-2°
|
0°
|
1°
|
0°
|
1°
|
2°
|
Additional weather information
Meteorologist's view
A very cold day with a severe wind chill and slippery conditions at height.
Weather
A mixture of sunny spells and a few sleet or snow showers during the morning. Showers becoming frequent and heavier in the afternoon and evening, merging into longer spells of rain and snow, with a small chance of lightning.
Chance of cloud-free hill tops
60% becoming 40%
Low cloud and visibility
Patchy cloud above 700m, falling lower at times in showers, then cloud becoming more extensive above 500m in the afternoon. Away from low cloud, visibility good but occasionally a few km or less in rain or snow.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Mostly dry with bright or clear spells and just the odd isolated shower possible, wintry above 400m. Turning cloudy in the evening with outbreaks of rain and summit snow by midnight.
Chance of cloud-free hill tops
80%, becoming 30% in evening.
Maximum wind speed expected
West or SW 20mph gusts 30mph, increasing south 30mph gusts 40mph late evening.
Temperature
- At 800m Minus 1C.
- Valley Plus 2C rising to 7C.
- Freezing level 600m.
Low cloud and visibility
Mainly good visibility. Some brief reductions in any showers. Cloud becoming extensive above 800m in the evening.
Mountain weather information
Sun 15 Mar
Sunrise:
Sunset:
Outbreaks of rain overnight and to start the morning. Bright spells and blustery showers following, wintry above 600m. Strong to gale force southwest winds. Freezing level above summits, falling to 900m in afternoon.
Mon 16 Mar
Sunrise:
Sunset:
Mainly dry with wintry showers dying out, then outbreaks of rain and summit snow arriving later. Remaining cold and windy with southwesterly gales on the tops. Freezing level 400m rising to 700m.
Tue 17 Mar
Sunrise:
Sunset:
Cloudy, perhaps with outbreaks of rain, strong winds likely. Milder with 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.