Eryri / Snowdonia Mountain weather forecast table
Confidence
High, but Medium for rainfall details on Monday.
This evening forecast
Strengthening SW winds, lowering cloud and outbreaks of rain.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
Gales
Poor Visibility
Storm Force Winds
Severe Chill Effect
Heavy Persistent Rain
Mountain weather forecast
Wet and very windy. Gale or storm force 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) |
70% | 90% | 80% | 80% | 80% | 80% | 90% | 90% |
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
SW
58
|
SW
58
|
S
54
|
S
56
|
S
62
|
S
60
|
S
61
|
S
58
|
| 600m |
S
38
|
S
39
|
S
37
|
S
39
|
S
43
|
S
42
|
S
43
|
S
41
|
| 300m |
S
24
|
S
24
|
S
23
|
S
24
|
S
27
|
S
27
|
S
27
|
S
25
|
| Valley |
S
24
|
S
24
|
S
23
|
S
25
|
S
27
|
S
27
|
S
27
|
S
26
|
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m | 69 | 69 | 65 | 67 | 74 | 73 | 75 | 71 |
| 600m | 48 | 49 | 47 | 50 | 55 | 55 | 56 | 53 |
| 300m | 42 | 42 | 41 | 43 | 48 | 47 | 48 | 46 |
| Valley | 42 | 42 | 41 | 44 | 48 | 48 | 49 | 46 |
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
4°
|
4°
|
4°
|
4°
|
4°
|
4°
|
4°
|
5°
|
| 600m |
6°
|
6°
|
6°
|
6°
|
6°
|
6°
|
6°
|
7°
|
| 300m |
8°
|
8°
|
8°
|
8°
|
8°
|
8°
|
8°
|
9°
|
| Valley |
9°
|
9°
|
9°
|
9°
|
9°
|
10°
|
10°
|
10°
|
| Freezing Level |
2,500m
|
2,900m
|
2,900m
|
2,900m
|
3,000m
|
2,900m
|
2,800m
|
2,600m
|
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
-5°
|
-4°
|
-4°
|
-4°
|
-4°
|
-4°
|
-4°
|
-4°
|
| 600m |
-1°
|
-1°
|
0°
|
0°
|
0°
|
0°
|
0°
|
0°
|
| 300m |
3°
|
4°
|
4°
|
4°
|
3°
|
4°
|
4°
|
4°
|
| Valley |
5°
|
5°
|
5°
|
5°
|
5°
|
5°
|
5°
|
6°
|
Additional weather information
Meteorologist's view
A poor day across the park with hazardous conditions.
Weather
Cloudy and overcast with outbreaks of rain, heavy and persistent at times. Buffeting at height along with poor or very poor visibility. Some flooding possible.
Chance of cloud-free hill tops
10%
Low cloud and visibility
Extensive low cloud base 300 to 600m. Visibility moderate to very poor.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Further heavy and persistent rain overnight and through daylight hours with a continuing flooding risk. The rain should turn lighter and patchy during the evening.
Chance of cloud-free hill tops
10% becoming 60% in the evening.
Maximum wind speed expected
South or Southwest 25 to 35mph gusting 50mph, easing at times.
Temperature
- At 800m Plus 2 to 5 Celsius
- Valley Plus 6 to 10 Celsius
- Freezing level Above the summits
Low cloud and visibility
Extensive low cloud base 300 to 500m, tending to lift and break late in the day. Visibility moderate to very poor, improving late in the day.
Mountain weather information
Tue 16 Dec
Dry and bright with some sunny or clear spells. Frost and valley fog or freezing fog possible. Light or moderate west or northwest, becoming southwest, winds at height. Freezing level well down early and late, but rising towards the summits by day.
Wed 17 Dec
Lowering cloud with outbreaks of rain, heavy at times. South or southwest winds becoming strong to gale force at height.
Thu 18 Dec
Further heavy and persistent rain possible, but confidence low. Gale force summit winds also possible.
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.