Eryri / Snowdonia Mountain weather forecast table
Confidence
High confidence in the unsettled and often very windy conditions prevailing during the next few days, but with a much brighter day on Friday after a wet Thursday.
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
Heavy Persistent Rain
Mountain weather forecast
A mainly dry start, but rain arriving late morning, occasionally heavy. Risk of gales on summits and ridges.
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
10% | 20% | 80% | 80% | 40% | 30% |
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
SW
25
|
S
37
|
S
35
|
S
34
|
SW
37
|
W
35
|
| 600m |
S
16
|
S
26
|
S
25
|
S
23
|
SW
27
|
W
23
|
| 300m |
S
9
|
S
18
|
S
16
|
S
14
|
SW
16
|
W
14
|
| Valley |
S
9
|
S
18
|
S
16
|
S
14
|
SW
16
|
W
15
|
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 29 | 43 | 42 | 41 | 45 | 43 |
| 600m | 20 | 32 | 31 | 29 | 35 | 31 |
| 300m | 18 | 30 | 27 | 25 | 30 | 27 |
| Valley | 18 | 30 | 27 | 24 | 30 | 27 |
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
4°
|
4°
|
3°
|
3°
|
4°
|
1°
|
| 600m |
6°
|
6°
|
5°
|
5°
|
5°
|
3°
|
| 300m |
8°
|
8°
|
8°
|
7°
|
7°
|
5°
|
| Valley |
8°
|
9°
|
9°
|
8°
|
8°
|
6°
|
| Freezing Level |
1,000m
|
1,200m
|
1,400m
|
1,500m
|
1,400m
|
900m
|
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-3°
|
-3°
|
-4°
|
-4°
|
-3°
|
-7°
|
| 600m |
2°
|
0°
|
0°
|
-1°
|
0°
|
-3°
|
| 300m |
5°
|
4°
|
4°
|
3°
|
3°
|
1°
|
| Valley |
6°
|
5°
|
5°
|
4°
|
5°
|
3°
|
Additional weather information
Meteorologist's view
Strong winds and summit gales will give a notable wind chill at height, this enhanced by the wet afternoon conditions. High watercourses will make river crossings hazardous, perhaps impassable.
Weather
A mainly dry morning with just a few patches of hill fog. Rain arrives by late morning, occasionally heavy so making for drenching conditions for a time into the afternoon. Rain then clears late aftenoon to leave scattered showers for the evening. Occasional strong winds at height and a risk of gales on summits and ridges.
Chance of cloud-free hill tops
40% decreasing to 20% in afternoon.
Low cloud and visibility
Patches of cloud on higher upslopes in the morning with generally good visibility otherwise. Visibility then deteriorating to a couple of kilometres or less in rain, with cloud bases thickening and lowering to 400m at times.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
A bright and very blustery day with sunny intervals. Dry for some but passing showers likely, some may be heavy with hail.
Chance of cloud-free hill tops
80%
Maximum wind speed expected
Gusting 40-50mph at height.
Temperature
- At 800m Plus 2 Celsius.
- Valley Plus 3 rising 8 Celsius.
- Freezing level 1000m
Low cloud and visibility
Patches of cloud down to around 700m in any showers, otherwise mainly clear with good visibility.
Mountain weather information
Sat 20 Dec
Strong winds, with gales or severe gales at height. A dry and bright start but turning cloudier with outbreaks of rain. Freezing level 1200m.
Sun 21 Dec
Fairly cloudy with a few outbreaks of rain. Freezing level 1000m. Moderate to fresh summit winds.
Mon 22 Dec
Remaining rather cloudy with a risk of a few spells of light rain. Fresh to strong summit winds and freezing level well 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.