Eryri / Snowdonia Mountain weather forecast table
Confidence
High for unsettled and changeable conditions during this period with potential for stormy conditions on Tuesday. Lower confidence for wind and rain details from Tuesday.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
Poor Visibility
Gales
Severe Chill Effect
Heavy Persistent Rain
Mountain weather forecast
Wet and windy with low cloud during the day.
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
30% | 90% | >95% | >95% | 60% | 20% |
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
SE
25
|
SE
30
|
S
37
|
SW
48
|
W
41
|
SW
36
|
| 600m |
S
20
|
S
23
|
SE
26
|
SW
32
|
W
29
|
SW
24
|
| 300m |
SE
12
|
SE
16
|
SE
18
|
SW
21
|
W
19
|
SW
15
|
| Valley |
SE
12
|
SE
16
|
SE
18
|
SW
21
|
W
19
|
SW
15
|
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 29 | 35 | 44 | 58 | 51 | 45 |
| 600m | 26 | 29 | 32 | 42 | 37 | 32 |
| 300m | 22 | 28 | 31 | 36 | 33 | 28 |
| Valley | 22 | 28 | 32 | 36 | 34 | 29 |
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
5°
|
6°
|
7°
|
8°
|
4°
|
4°
|
| 600m |
7°
|
8°
|
9°
|
9°
|
6°
|
6°
|
| 300m |
8°
|
10°
|
11°
|
11°
|
8°
|
8°
|
| Valley |
9°
|
11°
|
12°
|
12°
|
10°
|
9°
|
| Freezing Level |
2,300m
|
2,200m
|
2,700m
|
2,300m
|
1,600m
|
1,400m
|
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
0°
|
1°
|
2°
|
2°
|
-3°
|
-3°
|
| 600m |
3°
|
4°
|
5°
|
5°
|
1°
|
1°
|
| 300m |
6°
|
7°
|
8°
|
7°
|
5°
|
5°
|
| Valley |
7°
|
8°
|
9°
|
8°
|
6°
|
6°
|
Additional weather information
Meteorologist's view
Gusts of 50 to 60mph above 600m for a time in the afternoon. Difficult and potentially dangerous conditions on high exposed ridges and summits with slippery surfaces and a chance of being blown off balance.
Weather
A wet day with spells of rain or drizzle, turning heavy at times into the afternoon. Rain clearing soon after dark then clear spells and a few showers in the evening. Strong winds developing with summit gales in the afternoon and evening.
Chance of cloud-free hill tops
Nil chance for much of the day, but improving to perhaps 70% during the evening.
Low cloud and visibility
Patchy low cloud on the tops becoming extensive and lowering into the morning. Cloud and fog extensive above 300 or 400m for most of the day bringing difficult navigation conditions. Cloud slowly lifting after dark but continuing to affect higher summits.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Showers moving east during the early morning, some heavy with a small chance of hail and thunder. Otherwise largely dry with clear or sunny spells by day but remaining breezy. More persistent rain and stronger winds spreading north during the evening.
Chance of cloud-free hill tops
50% becoming 90%.
Maximum wind speed expected
South or Southwest 20 to 30mph with gusts 40 to 50mph.
Temperature
- At 800m Plus 4 or 5C.
- Valley Plus 8C rising to 11C.
- Freezing level Above summits.
Low cloud and visibility
Patchy cloud to 500 or 600m during the morning as showers move through, lifting above summits into the day. Mostly good visibility.
Mountain weather information
Tue 9 Dec
Very windy conditions with storm force winds likely for a time. A period of heavy rain in the morning followed by bright spells and showers. Freezing level above summits.
Wed 10 Dec
Bright spells and showers. Very strong and gusty westerly winds with severe gales at height. Freezing level above summits.
Thu 11 Dec
A window of drier and brighter weather with lighter winds is possible. Low confidence.
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.