Eryri / Snowdonia Mountain weather forecast table
Confidence
High for wet and windy conditions arriving on New Year's Eve then low confidence for the timings of heavy rain or snow clearing south during New Year's Day and transition to colder conditions.
This evening forecast
Cloudy with the odd spot of rain Strengthening southwesterly winds with gales later on the tops. Freezing level above summits.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
Gales
Heavy Persistent Rain
Storm Force Winds
Severe Chill Effect
Poor Visibility
Mountain weather forecast
Dry start then turning very wet and windy. Storm force winds on the tops.
00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
---|---|---|---|---|---|---|---|---|
Weather (at 800m) |
||||||||
Chance of precipitation (at 800m) |
10% | 10% | 20% | 30% | 90% | 90% | 90% | 90% |
00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
---|---|---|---|---|---|---|---|---|
900m |
SW
39
|
SW
41
|
SW
46
|
SW
52
|
SW
55
|
SW
53
|
SW
42
|
SW
37
|
600m |
SW
25
|
SW
30
|
SW
34
|
SW
38
|
SW
41
|
SW
40
|
SW
29
|
SW
27
|
300m |
SW
17
|
SW
20
|
SW
23
|
SW
26
|
SW
26
|
SW
25
|
SW
20
|
SW
18
|
Valley |
SW
18
|
SW
20
|
SW
24
|
SW
26
|
SW
28
|
SW
25
|
SW
20
|
SW
18
|
00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
---|---|---|---|---|---|---|---|---|
900m | 50 | 53 | 60 | 68 | 73 | 71 | 56 | 50 |
600m | 35 | 41 | 48 | 53 | 58 | 57 | 43 | 39 |
300m | 31 | 36 | 42 | 47 | 49 | 48 | 38 | 34 |
Valley | 33 | 38 | 43 | 47 | 52 | 47 | 37 | 33 |
00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
---|---|---|---|---|---|---|---|---|
900m |
3°
|
3°
|
3°
|
3°
|
4°
|
5°
|
4°
|
4°
|
600m |
5°
|
5°
|
5°
|
6°
|
6°
|
6°
|
6°
|
6°
|
300m |
7°
|
8°
|
7°
|
8°
|
8°
|
8°
|
8°
|
8°
|
Valley |
9°
|
9°
|
9°
|
9°
|
9°
|
10°
|
10°
|
9°
|
Freezing Level |
1,300m
|
1,300m
|
1,400m
|
1,600m
|
2,200m
|
2,100m
|
1,800m
|
1,600m
|
00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
---|---|---|---|---|---|---|---|---|
900m |
-5°
|
-5°
|
-5°
|
-5°
|
-5°
|
-3°
|
-3°
|
-4°
|
600m |
-1°
|
-1°
|
-1°
|
-1°
|
-1°
|
0°
|
0°
|
0°
|
300m |
4°
|
3°
|
3°
|
3°
|
3°
|
4°
|
4°
|
4°
|
Valley |
5°
|
5°
|
5°
|
5°
|
5°
|
6°
|
6°
|
5°
|
Additional weather information
Meteorologist's view
Gusts of 70 to 80mph on high ridges and summits will make walking almost impossible and hazardous. Severe conditions setting in from heavy rain, strong winds and wind chill.
Weather
Mainly dry overnight and much of the morning with patchy light rain. Rain becoming persistent and heavy from late morning onwards with drenching conditions for the rest of the day. Very windy with stormy conditions on the tops.
Chance of cloud-free hill tops
30% becoming 10% in afternoon.
Low cloud and visibility
Extensive cloud above 700 or 800m lowering to 500m during the afternoon. Away from low cloud, mainly good visibility at first but becoming poor once rain sets in.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Persistent and heavy rain and sleet, with snow mainly above 400m but perhaps to lower levels, overnight and in the morning. This is expected to clear south by afternoon but timings and snow levels are uncertain at this stage. Clear spells and showers following, wintry above 500m at first then to lower levels in evening.
Chance of cloud-free hill tops
10%, becoming 70% in afternoon.
Maximum wind speed expected
Southwesterly 40mph gusts 55mph overnight becoming Westerly or Northwesterly 25 to 30mph gusts 40mph.
Temperature
- At 800m Plus 1C falling to Minus 1C, then Minus 4 C in evening.
- Valley Plus 5 or 6C, falling to Plus 2C later.
- Freezing level 900m falling to 400m.
Low cloud and visibility
Extensive cloud above 500m overnight and to start the morning with poor or very poor visibility in rain or snow. Improving in the afternoon, but occasionally poor in wintry showers.
Mountain weather information
Thu 2 Jan
Mainly dry with sunny spells and scattered snow showers. Strong northerly winds on the tops with severe wind chill. Freezing level down to 200m.
Fri 3 Jan
Bright spells and wintry showers, turning to rain below 300m. Brisk northwest winds. Freezing level rising to 500m.
Sat 4 Jan
Bright intervals and scattered wintry showers, but mainly rain on low slopes. Light winds. Freezing level around 400m.
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.