Eryri / Snowdonia Mountain weather forecast table
Confidence
High for the mobile nature of the westerly weather patterns through Tuesday then for high pressure extending from the northeast thereafter, but lowering for the transitional timing detail.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
Severe Chill Effect
Poor Visibility
Gales
Heavy Persistent Rain
Mountain weather forecast
Showers merging to longer periods of rain from late morning. Strong to gale winds.
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
20% | 20% | 60% | 70% | 60% | 60% |
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
W
34
|
W
34
|
SW
32
|
SW
41
|
SW
42
|
SW
40
|
| 600m |
SW
21
|
SW
24
|
SW
24
|
SW
28
|
SW
27
|
SW
25
|
| 300m |
SW
13
|
W
15
|
SW
17
|
SW
18
|
SW
18
|
SW
17
|
| Valley |
SW
13
|
W
15
|
SW
16
|
SW
18
|
SW
18
|
SW
17
|
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 40 | 42 | 40 | 50 | 51 | 49 |
| 600m | 27 | 31 | 32 | 37 | 36 | 34 |
| 300m | 24 | 27 | 29 | 31 | 33 | 31 |
| Valley | 24 | 26 | 28 | 32 | 33 | 31 |
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-1°
|
0°
|
2°
|
3°
|
4°
|
4°
|
| 600m |
2°
|
3°
|
4°
|
5°
|
6°
|
6°
|
| 300m |
4°
|
5°
|
7°
|
7°
|
7°
|
7°
|
| Valley |
6°
|
7°
|
9°
|
8°
|
9°
|
9°
|
| Freezing Level |
700m
|
900m
|
1,100m
|
2,100m
|
2,000m
|
1,800m
|
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-10°
|
-8°
|
-6°
|
-4°
|
-4°
|
-3°
|
| 600m |
-5°
|
-4°
|
-1°
|
0°
|
0°
|
0°
|
| 300m |
0°
|
1°
|
3°
|
3°
|
3°
|
3°
|
| Valley |
2°
|
3°
|
5°
|
4°
|
5°
|
5°
|
Additional weather information
Meteorologist's view
Potentially hazardous conditions in extensive hill fog, driving rain and a severe wind chill at height late morning through to late afternoon. Gales across more exposed ridges and summits.
Weather
Beginning with limited brighter spells and perhaps some isolated showers, these wintry above 500-600m. Cloud thickening from the west to bring periods of rain from late morning, turning heavier early to mid-afternoon, before becoming patchy and light for the late afternoon and evening.
Chance of cloud-free hill tops
60% initially becoming 10% or less from mid-day
Low cloud and visibility
Good or very good becoming moderate or poor in rain and showers, very poor in early snow showers and within cloud, which becomes extensive from 500m from late morning
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Mainly cloudy with some patchy light rain and summit gales. Freezing level above summits.
Chance of cloud-free hill tops
10-20%
Maximum wind speed expected
South or southwest mean 30-40mph, with gusts reaching 60mph across more exposed ridges and summits.
Temperature
- At 800m Plus 4 Celsius
- Valley Plus 8 Celsius increasing 14 Celsius for the afternoon
- Freezing level Above summits
Low cloud and visibility
Good or very good becoming moderate or poor in rain, very poor within cloud, which will be quite extensive from 500m.
Mountain weather information
Wed 18 Mar
Dry with brighter spells increasing into the afternoon. Fresh to strong easterly summit winds developing late in day. Freezing level above summits.
Thu 19 Mar
Dry with bright and sunny spells. Fresh easterly summit winds. Freezing level above summits.
Fri 20 Mar
Dry with good sunny spells. Light 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.