Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
Confidence is high for the ongoing unsettled weather through the next five days, with most summits seeing freezing levels above summits. However, cloud detail remains only Moderate confidence even as early as Sunday, and falling to Low, along with the details of rain from Monday onward.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
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.
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.
Mountain weather forecast
Outbreaks of rain, perhaps summit snow. Extensive low cloud, and feeling cold.
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
<05% | 20% | 60% | 60% | 60% | 40% |
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
18
|
SE
17
|
SE
13
|
S
12
|
S
12
|
SE
12
|
| 600m |
SE
13
|
SE
11
|
SE
10
|
S
11
|
S
10
|
S
10
|
| 300m |
SE
9
|
SE
7
|
SE
6
|
S
5
|
SE
4
|
SE
5
|
| Valley |
SE
9
|
SE
8
|
SE
6
|
S
5
|
SE
4
|
SE
6
|
Wind gust (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 20 | 20 | 16 | 15 | 14 | 14 |
| 600m | 16 | 15 | 13 | 14 | 14 | 13 |
| 300m | 14 | 13 | 10 | 10 | 9 | 9 |
| Valley | 15 | 14 | 10 | 9 | 9 | 9 |
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
1°
|
1°
|
2°
|
2°
|
1°
|
1°
|
| 600m |
4°
|
3°
|
3°
|
4°
|
3°
|
3°
|
| 300m |
5°
|
5°
|
6°
|
6°
|
5°
|
4°
|
| Valley |
6°
|
6°
|
7°
|
7°
|
5°
|
5°
|
| Freezing Level |
1,000m
|
1,200m
|
1,200m
|
1,100m
|
1,000m
|
1,000m
|
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-4°
|
-4°
|
-3°
|
-3°
|
-4°
|
-4°
|
| 600m |
0°
|
0°
|
0°
|
0°
|
-1°
|
-1°
|
| 300m |
2°
|
3°
|
3°
|
4°
|
3°
|
2°
|
| Valley |
3°
|
4°
|
5°
|
5°
|
4°
|
3°
|
Additional weather information
Meteorologist's view
A cold day on the tops with a significant wind chill, especially in rain and sleet. Difficult navigation conditions with extensive low cloud.
Weather
A mostly dry start with some low cloud, and the best of any brightness in the northeast. Outbreaks of rain will soon spread northwards, most likely across eastern hills, where they could become persistent and heavy at times, and perhaps some sleet or snow above 800m. Western hills have a reasonable start of seeing drier conditions persisting, but some outbreaks of rain cannot be ruled out here.
Chance of cloud-free hill tops
10% but 20% in the northeast.
Low cloud and visibility
Extensive cloud will obscure summits above 500m, and occasionally down to 300m, especially on southern facing slopes or during rain. Cloud perhaps clearing from summits below 700m at times in the northwest. Away from low cloud, visibility will be rather hazy and often dropping to a few kilometres in rain or sleet.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Some clearer intervals possible overnight, but also valley mist and fog. After a bright start, especially across western hills, there is a chance of thicker cloud moving in from the east at times. This bringing further outbreaks of rain. Western hills likely drier, and there is some chance that drier and brighter or sunnier conditions persist for many parts.
Chance of cloud-free hill tops
60% in the west, 30% in the east.
Maximum wind speed expected
Southeast 20mph gusts 30mph.
Temperature
- At 800m Plus 2 Celsius.
- Valley Plus 4 rising to Plus 8 Celsius.
- Freezing level Above summits.
Low cloud and visibility
Low confidence in detail, but early mist and fog through valleys will clear through the morning to leave some clearer periods, but areas of cloud perhaps obscuring hills above 600m at times. Some eastern hills likely also seeing periods of cloud obscuring summits above 500m, and perhaps 300m at times, especially during any rain. Outside of cloud, some good views of distant hills are possible, but visibility could fall to a few kilometres in any rain.
Mountain weather information
Tue 20 Jan
Sunrise:
Sunset:
Low cloud with outbreaks of rain, but some drier and brighter spells. Further rain and summit snow through the evening. Strong southerly winds with a significant wind chill. Freezing level above summits.
Wed 21 Jan
Sunrise:
Sunset:
Outbreaks of rain, heavy at times with sleet or snow on highest tops. Gale force southerly winds with a severe wind chill. Freezing level above summits, but perhaps lowering to 900m with rain.
Thu 22 Jan
Sunrise:
Sunset:
It is expected to remain unsettled and very windy with further periods of rain. Severe gale force southerly winds. 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.