Eryri / Snowdonia Mountain weather forecast table
Confidence
High for east to southeast flow persisting also for relatively unsettled, but lowering for timing detail of worst of conditions.
This evening forecast
Rain at first, above 800m snow, clearing towards midnight. Severe wind chill at height in strong southeast summit winds. Freezing level around 900m.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
Gales
Severe Chill Effect
Poor Visibility
Storm Force Winds
Mountain weather forecast
Fair start, then periods of rain from late morning. Gale to storm force southeast summit winds.
| 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% | <05% | 20% | 80% | 80% | 90% | 80% |
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
S
31
|
S
28
|
SE
29
|
SE
42
|
E
47
|
SE
40
|
SE
40
|
SE
38
|
| 600m |
S
23
|
S
19
|
SE
21
|
SE
29
|
E
33
|
SE
29
|
SE
29
|
SE
27
|
| 300m |
S
15
|
S
12
|
SE
13
|
SE
21
|
SE
24
|
SE
20
|
SE
20
|
SE
19
|
| Valley |
S
15
|
S
12
|
SE
14
|
SE
21
|
SE
24
|
SE
20
|
SE
21
|
SE
20
|
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m | 38 | 33 | 35 | 52 | 60 | 52 | 52 | 50 |
| 600m | 29 | 26 | 29 | 40 | 45 | 41 | 40 | 39 |
| 300m | 27 | 22 | 25 | 37 | 42 | 36 | 36 | 35 |
| Valley | 28 | 23 | 26 | 37 | 41 | 36 | 36 | 35 |
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
0°
|
0°
|
-1°
|
-1°
|
0°
|
4°
|
4°
|
3°
|
| 600m |
2°
|
2°
|
2°
|
1°
|
2°
|
6°
|
6°
|
5°
|
| 300m |
4°
|
4°
|
3°
|
3°
|
5°
|
8°
|
8°
|
8°
|
| Valley |
5°
|
5°
|
4°
|
4°
|
6°
|
9°
|
9°
|
9°
|
| Freezing Level |
800m
|
900m
|
700m
|
700m
|
1,600m
|
1,600m
|
1,600m
|
1,600m
|
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
-8°
|
-8°
|
-9°
|
-11°
|
-9°
|
-4°
|
-4°
|
-4°
|
| 600m |
-5°
|
-4°
|
-5°
|
-7°
|
-5°
|
0°
|
0°
|
0°
|
| 300m |
0°
|
0°
|
-2°
|
-2°
|
-1°
|
4°
|
4°
|
4°
|
| Valley |
1°
|
1°
|
0°
|
-1°
|
1°
|
5°
|
5°
|
5°
|
Additional weather information
Meteorologist's view
Severe wind chill effect receding as the freezing level lifts later in the day. Some risk of gusts reaching storm force (70mph) for a time early afternoon across highest and most exposed ridges and summits.
Weather
Patchy rain and above 700-800m snow, at first overnight, clearing before dawn as the cloud becomes more broken. Cloud soon thickening from the south, bringing patchy rain by late morning, occasionally wintry across highest peaks at first. Outbreaks turning more persistent and heavy for the afternoon, before weakening mid to late evening.
Chance of cloud-free hill tops
40% becoming 10-20% from late morning
Low cloud and visibility
Good or very good, becoming moderate or poor in rain, very poor in snow and within cloud with bases becoming quite extensive from 600m from late morning with patches lower down for the afternoon.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Cloudy with occasional rain, which turns heavier at times for the afternoon and evening, also turning to snow above 800m from late afternoon. Strong southeast summit winds bringing a severe wind chill to higher peaks.
Chance of cloud-free hill tops
20%
Maximum wind speed expected
Southeast mean 30-35mph with gusts reaching 45mph across exposed ridges and summits.
Temperature
- At 800m Plus 4 Celsius decreasing plus 2 Celsius by early evening
- Valley Plus 7 Celsius increasing 10 Celsius for the afternoon
- Freezing level Above summits lowering 900-1000m for the evening
Low cloud and visibility
Good or very good, becoming moderate or poor in rain, very poor in snow and within cloud with bases quite extensive from 600m with patches lower down.
Mountain weather information
Fri 23 Jan
Mainly cloudy with occasional rain, with snow above 800m. Strong to gale southeast summit winds bringing a severe wind chill at height. Freezing level around 900m.
Sat 24 Jan
Mainly cloudy with some patchy light rain and summit snow. Strong easterly winds. Freezing level around 800m.
Sun 25 Jan
Mainly cloudy with patchy light rain and summit snow. Fresh easterly winds. Freezing level around 700-800m.
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.