Eryri / Snowdonia Mountain weather forecast table
Confidence
High for an unsettled period with spells of rain and strong winds, but also some drier intervals. Also High for temperatures remaining on the mild side, with the freezing level remaining above the summits. Low confidence for rainfall details, especially from Monday onwards, and for the potential for very windy conditions on Tuesday.
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
Thunderstorms
Heavy Persistent Rain
Mountain weather forecast
Frequent showers, some heavy, with low cloud. Cold and windy at height.
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
70% | 70% | 60% | 60% | 70% | 30% |
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
SW
36
|
SW
35
|
SW
38
|
W
43
|
W
41
|
W
32
|
| 600m |
SW
25
|
SW
24
|
SW
27
|
W
31
|
W
28
|
SW
22
|
| 300m |
SW
16
|
SW
16
|
SW
18
|
W
21
|
W
19
|
SW
15
|
| Valley |
SW
16
|
SW
16
|
SW
18
|
W
21
|
W
19
|
SW
16
|
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 42 | 42 | 47 | 53 | 51 | 40 |
| 600m | 30 | 30 | 35 | 40 | 38 | 30 |
| 300m | 27 | 27 | 32 | 37 | 34 | 28 |
| Valley | 27 | 27 | 31 | 37 | 34 | 28 |
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
4°
|
4°
|
4°
|
4°
|
4°
|
4°
|
| 600m |
6°
|
6°
|
6°
|
6°
|
6°
|
6°
|
| 300m |
8°
|
8°
|
8°
|
8°
|
8°
|
8°
|
| Valley |
9°
|
9°
|
10°
|
10°
|
10°
|
9°
|
| Freezing Level |
1,400m
|
1,500m
|
1,500m
|
1,600m
|
1,600m
|
1,500m
|
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-4°
|
-3°
|
-3°
|
-3°
|
-3°
|
-3°
|
| 600m |
0°
|
1°
|
1°
|
0°
|
0°
|
0°
|
| 300m |
4°
|
4°
|
4°
|
4°
|
4°
|
4°
|
| Valley |
6°
|
6°
|
6°
|
6°
|
6°
|
6°
|
Additional weather information
Meteorologist's view
Blustery, with gales at height, leading to a chance of being blown over. While relatively mild for December at low levels, warm waterproof layers are still essential, with the wind chill leading to it feeling sub-zero on exposed higher routes.
Weather
Mainly cloudy with frequent showers, some heavy with a small chance of hail and thunder. A few fleeting bright or clear intervals, mainly on lower slopes in the east. Rain clearing in the evening with clear spells developing.
Chance of cloud-free hill tops
20% in west, 40% in the east.
Low cloud and visibility
Frequent cloud obscuring routes above 800m, with some patches possible down to 500m in heavier showers. Away from low cloud, visibility will be good, falling to a few km at times in showers.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Dry with clear spells overnight. Cloud and outbreaks of rain or drizzle will soon arrive from the southwest and lasting through the day, heavy at times. Rain then clearing in the evening to leave clear spells and a few mist patches.
Chance of cloud-free hill tops
60% overnight, becoming 10% for much of daylight hours, improving to 80% during the evening.
Maximum wind speed expected
Southwest 25-35mph with gusts 50mph.
Temperature
- At 800m Plus 4 Celsius rising to Plus 7 Celsius.
- Valley Plus 8 Celsius rising to Plus 13 Celsius.
- Freezing level Above summits.
Low cloud and visibility
Patchy cloud above 500m at first, becoming extensive through the morning. Cloud lifting and breaking in the evening. Good visibility becoming moderate to poor by the afternoon with rain, improving again in the evening.
Mountain weather information
Mon 8 Dec
Bright spells and showers, some heavy with a small chance of thunder. Strong southwest winds with gusts 50mph on the tops. Freezing level above summits.
Tue 9 Dec
A wet and windy day is likely, with gales to lower levels, and a chance of storm force winds on high slopes. Freezing level well above summits.
Wed 10 Dec
A brighter day is expected with a few showers, perhaps heavy at times. Strong southwest winds. Freezing level above summits.
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.