Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
Confidence high for a fine day Tuesday and much milder towards the end of the week but lower for timing of any more persistent rain, and very low on Saturday due to uncertainties over the development of a low close to the SW United Kingdom.
This evening forecast
Occasional sleet or snow showers, falling increasingly as rain below about 600m, through the evening with clear spells developing more widely. Strong northerly winds easing, but still a significant chill effect.
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
Dry with long sunny spells. Northerly winds easing but still cold
| 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) |
30% | 10% | <05% | <05% | <05% | <05% | <05% | <05% |
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 |
N
27
|
N
24
|
N
24
|
N
22
|
N
20
|
N
17
|
N
15
|
NE
8
|
| 600m |
N
18
|
N
12
|
N
12
|
N
12
|
N
14
|
N
10
|
NE
6
|
E
4
|
| 300m |
N
11
|
NW
6
|
N
7
|
N
7
|
N
10
|
N
6
|
N
3
|
SE
2
|
| Valley |
N
11
|
NW
7
|
N
7
|
N
7
|
N
10
|
N
6
|
N
3
|
S
3
|
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 | 34 | 29 | 29 | 27 | 26 | 21 | 17 | 10 |
| 600m | 24 | 17 | 17 | 16 | 19 | 14 | 9 | 5 |
| 300m | 22 | 15 | 16 | 15 | 17 | 12 | 7 | 3 |
| Valley | 23 | 16 | 17 | 16 | 17 | 13 | 7 | 4 |
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
0°
|
0°
|
-1°
|
0°
|
0°
|
0°
|
-1°
|
-1°
|
| 600m |
2°
|
2°
|
2°
|
2°
|
3°
|
2°
|
1°
|
1°
|
| 300m |
4°
|
4°
|
4°
|
4°
|
6°
|
5°
|
3°
|
2°
|
| Valley |
6°
|
5°
|
5°
|
6°
|
7°
|
6°
|
5°
|
4°
|
| Freezing Level |
800m
|
800m
|
700m
|
700m
|
900m
|
800m
|
800m
|
700m
|
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
-8°
|
-8°
|
-8°
|
-7°
|
-6°
|
-6°
|
-7°
|
-5°
|
| 600m |
-3°
|
-3°
|
-3°
|
-3°
|
-2°
|
-2°
|
-2°
|
-1°
|
| 300m |
1°
|
1°
|
1°
|
1°
|
2°
|
3°
|
2°
|
1°
|
| Valley |
2°
|
3°
|
2°
|
3°
|
4°
|
4°
|
4°
|
3°
|
Additional weather information
Meteorologist's view
Temperatures in valleys around zero Celsius at dawn and again towards midnight. Feeling bitterly cold at height despite the sunshine and easing winds.
Weather
Remaining rain, sleet and snow showers soon dying out then a dry night with long clear spells. Then a chilly start to a dry and largely sunny day. Remaining dry through the evening with long clear spells and a widespread frost developing.
Chance of cloud-free hill tops
Around 75% at first, but rising close to 100% by late morning.
Low cloud and visibility
Occasional cloud above 450-600m through the early hours and first half of the morning otherwise little or no cloud expected below the summits. Away from cloud visibility excellent with good panoramic views of surrounding hills and mountains, but just a few kilometres in early sleet or snow showers.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Largely clear with a widespread frost and a few mist and fog patches, but cloud above the summits tending to increase towards the end of the night. Some early bright spells in the north but generally a cloudy morning with outbreaks of rain, preceded briefly by sleet or wet snow, spreading east towards midday. The rain becoming more persistent and occasionally heavy for a time in the afternoon before turning lighter and patchier again for the evening.
Chance of cloud-free hill tops
Close to 100% at first falling close to zero, but nearer 25% in north, by early afternoon.
Maximum wind speed expected
Southerly 10mph increasing 15-20mph through the morning, gusts around 40mph over ridges and summits, veering southwesterly 15-20mph in the evening.
Temperature
- At 800m Around minus 1 or 2 Celsius rising steadily to plus 6 or 7 Celsius by evening
- Valley Around minus 3 or 4 Celsius at dawn rising to plus 7 or 8 Celsius through the day
- Freezing level Initially falling to 300m or less by dawn then rising above the summits by midday.
Low cloud and visibility
Occasional cloud above about 600m in the south, otherwise little or no cloud below the summits at first becoming periods or persistent above 450-600m, but more occasional above 750m at times in north, by early afternoon, with patches below 300m later, especially in west. Away from cloud visibility excellent falling to several kilometres in rain and sleet, and perhaps briefly a kilometre in summit snow and less in low level mist or fog patches.
Mountain weather information
Thu 27 Nov
Sunrise:
Sunset:
Mild, cloudy day with outbreaks of rain, occasionally heavy for a time later before clearing east and cloud breaking in evening. Strong southwesterly winds. Freezing level well above summits, but falling later.
Fri 28 Nov
Sunrise:
Sunset:
Clear or sunny spells and showers, turning increasingly wintry on higher summits. Occasionally strong westerly or southwesterly winds. Freezing level falling close to highest summits.
Sat 29 Nov
Sunrise:
Sunset:
Rather cloudy with showers or longer spells of occasionally heavy rain, some snow on higher summits. Fresh southerly or southwesterly winds. Freezing level close to highest 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.