Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High for a largely fine but cold day Saturday but lower for timings for the arrival of evening snow, clearance on Sunday and change to northerly winds Monday, but reasonably high for a drier conditions towards midweek.
This evening forecast
Cloud and outbreaks of mainly light snow soon clearing south this evening with clear spells and the odd snow shower following. Feeling bitterly cold despite the strong northeasterly winds easing.
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.
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.
Heavy Persistent Snow
Heavy snow can lead to rapid changes in underfoot conditions and paths may become treacherous or hidden. It also brings very poor visibility and often makes navigation much more challenging. When deep snow accumulates progress is often time consuming and strenuous, significantly affecting the distance one can travel on foot. Deep drifts can develop if snow is combined with strong winds. A heightened avalanche risk is possible and avalanche reports should be consulted where available.
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.
Mountain weather forecast
Mainly dry with sunny spells but cloud increasing, evening snow. Windy in evening
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
|
|
Chance of precipitation (at 800m) |
10% | 10% | 10% | 10% | <05% | <05% | 20% | 80% |
Wind direction and speed (mph)
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
NE
21
|
N
17
|
NW
14
|
NW
11
|
SW
7
|
S
13
|
S
26
|
S
35
|
| 600m |
N
10
|
N
8
|
W
6
|
SW
5
|
SW
6
|
S
11
|
S
17
|
S
24
|
| 300m |
N
5
|
N
3
|
SW
3
|
SW
3
|
SW
5
|
S
9
|
S
12
|
S
17
|
| Valley |
N
5
|
N
3
|
SW
3
|
S
4
|
SW
5
|
S
8
|
S
12
|
S
17
|
Wind gust (mph)
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m | 27 | 21 | 17 | 14 | 11 | 18 | 33 | 46 |
| 600m | 14 | 12 | 8 | 8 | 10 | 17 | 25 | 35 |
| 300m | 12 | 11 | 6 | 6 | 8 | 15 | 23 | 33 |
| Valley | 12 | 10 | 6 | 6 | 7 | 14 | 22 | 32 |
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
-4°
|
-5°
|
-5°
|
-4°
|
-2°
|
-2°
|
-3°
|
-4°
|
| 600m |
-2°
|
-3°
|
-3°
|
-1°
|
0°
|
0°
|
0°
|
-2°
|
| 300m |
0°
|
0°
|
-1°
|
0°
|
3°
|
3°
|
2°
|
0°
|
| Valley |
2°
|
1°
|
1°
|
2°
|
4°
|
4°
|
4°
|
2°
|
| Freezing Level |
200m
|
100m
|
100m
|
300m
|
600m
|
600m
|
400m
|
300m
|
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
-12°
|
-12°
|
-11°
|
-9°
|
-7°
|
-8°
|
-11°
|
-14°
|
| 600m |
-7°
|
-7°
|
-6°
|
-4°
|
-3°
|
-5°
|
-6°
|
-10°
|
| 300m |
-2°
|
-2°
|
-3°
|
-2°
|
1°
|
-1°
|
-3°
|
-6°
|
| Valley |
0°
|
0°
|
-1°
|
0°
|
2°
|
1°
|
0°
|
-4°
|
Additional weather information
Meteorologist's view
Valley temperatures around minus 1 or 2 Celsius at dawn. Very cold at height despite the sunshine. Gusts close to 65mph over higher ridges and summits in late evening.
Weather
The odd snow shower through the early hours but most places dry with long clear spells. Any remaining snow showers soon dying out with sunny spells through the morning, the sunshine though becoming increasingly hazy as cloud above the summits increases for the afternoon. Outbreaks of snow, becoming occasionally heavy, will spread east through the evening, with the possibility, especially on higher mountains, of blizzard conditions.
Chance of cloud-free hill tops
Around 90%, but chances fall towards zero through the evening.
Low cloud and visibility
Only small amounts of cloud expected below summit level through daylight hours but becoming periods or persistent cloud above 450-600m, with patches below, from the west through the evening. Away from cloud, visibility generally excellent with good panoramic views of surrounding hills, but just a few kilometres in early snow showers and snow later, and near zero in heavier snow and blizzards.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Cloud and occasionally heavy snow, falling increasingly as rain below about 900m, with blizzard conditions and drifting snow possible, especially over the higher mountains. The rain and summit snow clear east during the late morning with heavy showers following for the afternoon and evening, these increasingly wintry above about 600m.
Chance of cloud-free hill tops
Little chance through much of the morning improving to 60% for the afternoon.
Maximum wind speed expected
Southerly 35 to 45mph, gusts around 70mph over ridges and summits, becoming westerly 20-25mph, gusts around 40mph over ridges and summits, by late morning.
Temperature
- At 800m Around minus 3 Celsius rising to around plus 3 Celsius, falling back to zero in afternoon
- Valley Around plus 2 Celsius rising to plus 6 or 7 Celsius by day
- Freezing level 300m or less rising above the summits around or soon after dawn, falling back to 750m in afternoon
Low cloud and visibility
Periods or persistent cloud above 450-600m, with patches below, through much of the morning becoming more occasional above 600-750m for the afternoon. Away from cloud, visibility just a few kilometres in rain and snow, but less than a kilometre in heavier snow and near zero in blizzards and drifting snow, becoming very good or excellent for the afternoon with temporary reductions in showers.
Mountain weather information
Mon 16 Feb
Sunrise:
Sunset:
Sunny spells and wintry showers, these turning to snow at lower levels as the occasionally strong westerly wind turns more northerly. Freezing level around 750m falling to 600m.
Tue 17 Feb
Sunrise:
Sunset:
A few showers at first, otherwise mainly dry with sunny spells. Occasionally strong northerly winds easing and backing more easterly. Freezing level 300m, rising to around 600m for a time.
Wed 18 Feb
Sunrise:
Sunset:
A dry day with sunny spells, risk of evening rain and snow. Strengthening easterly or southeasterly breeze. Freezing level 300m or less, rising later
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.