Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High for a mostly fine and dry day on Wednesday. Also high for winds strengthening Thursday, but moderate for the strength of the strongest gusts, and the timing for the heaviest rain. Confidence then high for colder conditions to follow, however the extent of any snowfall, and also the snow-level on the hills is only moderate confidence. This confidence becoming low for any details by the weekend.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
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.
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
Largely dry with sunny spells and just the odd shower. Brisk winds
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
20% | 20% | 20% | 20% | 20% | 20% |
Wind direction and speed (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
W
38
|
W
34
|
W
31
|
W
31
|
SW
36
|
SW
39
|
| 600m |
W
25
|
W
25
|
W
24
|
SW
24
|
SW
22
|
SW
25
|
| 300m |
W
15
|
W
17
|
W
18
|
SW
17
|
SW
14
|
SW
16
|
| Valley |
W
15
|
W
17
|
W
18
|
SW
17
|
SW
13
|
SW
15
|
Wind gust (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 45 | 42 | 40 | 39 | 44 | 48 |
| 600m | 31 | 32 | 32 | 32 | 30 | 35 |
| 300m | 28 | 29 | 29 | 29 | 27 | 32 |
| Valley | 28 | 29 | 29 | 29 | 27 | 30 |
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
0°
|
0°
|
0°
|
1°
|
1°
|
1°
|
| 600m |
2°
|
2°
|
3°
|
4°
|
4°
|
4°
|
| 300m |
5°
|
5°
|
6°
|
7°
|
6°
|
6°
|
| Valley |
6°
|
7°
|
8°
|
9°
|
8°
|
8°
|
| Freezing Level |
800m
|
800m
|
800m
|
900m
|
900m
|
1,000m
|
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-9°
|
-8°
|
-8°
|
-6°
|
-7°
|
-7°
|
| 600m |
-4°
|
-4°
|
-3°
|
-2°
|
-2°
|
-3°
|
| 300m |
0°
|
0°
|
2°
|
3°
|
2°
|
2°
|
| Valley |
2°
|
2°
|
4°
|
5°
|
4°
|
4°
|
Additional weather information
Meteorologist's view
Cold across the tops, especially with the strong winds, with strong gusts impeding progress at times. Warm, windproof layers essential.
Weather
A fine but windy day with cloud around or just above summits and some sunny spells likely. The odd shower cannot be ruled out and these could include the odd spell of sleet or brief snow above 800m. Feeling rather cold in the brisk breeze, especially on the summits. Winds strengthening after dark.
Chance of cloud-free hill tops
80% in the east, 60% in the west through the morning.
Low cloud and visibility
Occasional cloud obscuring summits above 600m during the morning, mainly in the west, with cloud lifting a little through the day to around 900m by the afternoon with breaks likely to give some clear summits. However, any showers could lead to this briefly dropping back to 600m at times. Outside of cloud, visibility will be good to very good, falling to moderate in any showers.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Winds strengthening early hours and through the morning, with outbreaks of rain and drizzle, more persistent on western slopes. Storm-force gusts are likely to develop, before a band of rain moves south though the afternoon. This heavy and very gusty for a time, and the odd rumble of thunder cannot be ruled out as the heaviest bursts move through. Some clearer, but also colder conditions following after dark, although winds easing.
Chance of cloud-free hill tops
Falling to 20% by dawn. Rising after dark to 60% by midnight.
Maximum wind speed expected
Southwesterly 50-60mph with gusts 70-80 mph, isolated 80-90mph possible.
Temperature
- At 800m Plus 4 Celsius, falling to Zero Celsius after dark
- Valley Plus 5 Celsius rising to Plus 12 Celsius
- Freezing level Mainly above the summits, falling after dark to 800m by midnight
Low cloud and visibility
Cloud thickening to obscure hills above 800m during the early hours, before lowering to 500m through the morning, most widely in the west. Cloud clearing through the evening, however some patches persisting at 600m. Moderate to Good visibility at first, but poor in rain, and briefly poor to very poor as any heavy rain moves through.
Mountain weather information
Fri 13 Mar
Sunrise:
Sunset:
Bright spells and a few showers, falling as snow above 400m. Winds easing compared to Thursday, but still rather breezy, with a notable wind chill. Freezing level 600m, perhaps briefly 300m.
Sat 14 Mar
Sunrise:
Sunset:
Any showers easing early Saturday, with freezing levels rising to around 800m by midday. Further showers, snow above 800m, spreading east later, with freezing level rising to just above summits.
Sun 15 Mar
Sunrise:
Sunset:
Winds strengthening, with occasional rain early on Sunday. Occasional showers follow, turning to snow above 600m during the late afternoon and evening as freezing levels fall to 700m
Updated at:
Summit specific forecast
Mountain summit forecast map
Loading map…
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.