Eryri / Snowdonia Mountain weather forecast table
Confidence
Medium
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
Blizzards
Heavy Persistent Snow
Gales
Severe Chill Effect
Poor Visibility
Heavy Persistent Rain
Storm Force Winds
Mountain weather forecast
Mainly dry start. Heavy snow with blizzards possible later.
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
10% | 30% | 50% | 70% | 90% | 90% |
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
NW
14
|
SW
7
|
SE
4
|
E
19
|
NE
36
|
NE
39
|
| 600m |
W
7
|
SW
6
|
SE
4
|
E
13
|
NE
23
|
NE
26
|
| 300m |
W
3
|
S
3
|
SE
3
|
E
9
|
NE
14
|
NE
17
|
| Valley |
W
3
|
S
3
|
SE
3
|
E
9
|
NE
14
|
NE
17
|
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 16 | 10 | 6 | 24 | 44 | 47 |
| 600m | 9 | 7 | 5 | 20 | 30 | 34 |
| 300m | 7 | 7 | 5 | 17 | 26 | 30 |
| Valley | 8 | 7 | 5 | 17 | 25 | 29 |
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
0°
|
0°
|
-1°
|
-1°
|
-2°
|
-3°
|
| 600m |
2°
|
2°
|
1°
|
1°
|
0°
|
-2°
|
| 300m |
4°
|
3°
|
4°
|
3°
|
1°
|
0°
|
| Valley |
4°
|
4°
|
5°
|
4°
|
2°
|
1°
|
| Freezing Level |
900m
|
800m
|
700m
|
700m
|
500m
|
300m
|
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-5°
|
-4°
|
-3°
|
-8°
|
-12°
|
-14°
|
| 600m |
-1°
|
-1°
|
-1°
|
-4°
|
-8°
|
-10°
|
| 300m |
2°
|
2°
|
2°
|
-1°
|
-4°
|
-6°
|
| Valley |
3°
|
3°
|
4°
|
1°
|
-2°
|
-5°
|
Additional weather information
Meteorologist's view
Note marked deterioration in conditions in the afternoon.
Weather
Overcast and misty with patchy light rain and snow early morning. Dry for a time with some morning brighter spells possible. Rain and snow arriving mid-afternoon, quickly becoming heavy and persistent with blizzard conditions at height along with a severe wind chill, white out conditions likely at times.
Chance of cloud-free hill tops
40%, for a time in the afternoon, otherwise 10% or less.
Low cloud and visibility
Overcast base 300 to 600m, possibly lifting and breaking near or above the summits in the afternoon. Visibility moderate to very poor in cloud and snow, perhaps becoming good for a time during the afternoon.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Outbreaks of heavy snow overnight with blizzard conditions possible. The snow becoming more showery by the morning and expected to be mainly rain and sleet at lower levels. Snow and rain showers continuing during the afternoon and evening.
Chance of cloud-free hill tops
10% or less at first becoming 60% by afternoon.
Maximum wind speed expected
North or Northwest 45mph gusting 50-55mph at first with a severe wind chill and possible blizzard conditions across summits.
Temperature
- At 800m Minus 4 Celsius
- Valley Zero to Plus 3 Celsius
- Freezing level Typically 300 to 500m, but could be lower early and late in the period.
Low cloud and visibility
Occasional or extensive cloud, base 300 to 600m lifting and breaking towards in summits, except in showers. Visibility often moderate to very poor at first in cloud and snow, becoming good at times later.
Mountain weather information
Sat 10 Jan
Often dry, clear and cold with a widespread frost and freezing at most levels. Snow showers with rain or sleet low down. Moderate or fresh northwesterly winds.
Sun 11 Jan
Starting dry with bright or clear spells. Cold. Rain and snow later with blizzard conditions developing at height along with severe gale southerly winds.
Mon 12 Jan
Milder with rain or showers. Strong to gale force southwest winds.
Summit specific forecast
Mountain summit forecast map
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.