
Eryri / Snowdonia Mountain weather forecast table
Confidence
High confidence for unsettled conditions to dominate but lower confidence for frontal zone positions and associated cloud and rainfall detail.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
Gales
Poor Visibility
Heavy Persistent Rain
Strong Sunlight
Mountain weather forecast
Wet for much of the day, although perhaps a brief drier interlude in the afternoon. Strong winds at summit level.
Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
>95% | >95% | 30% | 20% | 10% | 20% |
Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
---|---|---|---|---|---|---|
900m |
SW
50
|
SW
43
|
SW
35
|
SW
32
|
SW
32
|
SW
31
|
600m |
SW
34
|
SW
30
|
SW
27
|
SW
26
|
SW
24
|
SW
22
|
300m |
SW
20
|
SW
19
|
SW
17
|
SW
16
|
SW
14
|
SW
13
|
Valley |
SW
20
|
SW
19
|
SW
16
|
SW
16
|
SW
14
|
SW
13
|
Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
---|---|---|---|---|---|---|
900m | 59 | 52 | 44 | 42 | 41 | 39 |
600m | 42 | 38 | 36 | 35 | 32 | 29 |
300m | 35 | 33 | 30 | 30 | 27 | 24 |
Valley | 35 | 32 | 29 | 29 | 26 | 24 |
Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
---|---|---|---|---|---|---|
900m |
11°
|
12°
|
11°
|
10°
|
9°
|
9°
|
600m |
13°
|
14°
|
13°
|
12°
|
11°
|
11°
|
300m |
15°
|
15°
|
16°
|
15°
|
13°
|
13°
|
Valley |
16°
|
16°
|
17°
|
16°
|
15°
|
14°
|
Freezing Level |
3,900m
|
2,900m
|
2,600m
|
2,400m
|
2,500m
|
2,500m
|
Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
---|---|---|---|---|---|---|
900m |
5°
|
6°
|
6°
|
5°
|
4°
|
4°
|
600m |
8°
|
9°
|
9°
|
8°
|
7°
|
7°
|
300m |
11°
|
12°
|
13°
|
12°
|
11°
|
10°
|
Valley |
12°
|
13°
|
15°
|
14°
|
12°
|
12°
|
Additional weather information
Meteorologist's view
Wet conditions in the morning, slippery underfoot so waterproofs will be needed. Winds at summit level could be particularly strong around exposed peaks and ridges.
Weather
Heavy rain overnight and early on Wednesday, easing through the morning to become generally dry by the afternoon. A small chance of outbreaks of light rain and drizzle through the day, especially on western slopes. Perhaps some drier interludes in the afternoon in eastern shelter but this is low confidence.
Chance of cloud-free hill tops
Near zero for much of the day.
Low cloud and visibility
Extensive bases above 400m, perhaps lower at times on western slopes. Perhaps a few breaks developing for a time in eastern shelter in the afternoon, but this is low confidence. Visibility generally moderate to poor in outbreaks of rain and very poor in summit cloud.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Most likely staying wet with further outbreaks of rain, perhaps heavy at times, especially across western slopes. Becoming drier in the afternoon, though there will be plenty of low cloud around. Windy across the summits.
Chance of cloud-free hill tops
Near zero for much of the day.
Maximum wind speed expected
South-southwest 40-50mph, gust 50-60mph.
Temperature
- At 800m Plus 12 Celsius
- Valley Plus 13 Celsius rising to 18 Celsius.
- Freezing level Well above summits.
Low cloud and visibility
Extensive bases above 400-600m, with visibility generally moderate to poor in outbreaks of rain and very poor in summit cloud.
Mountain weather information
Fri 19 Sep
The band of cloud and rain should clear south for a time before returning north again later. Strong southwest winds.
Sat 20 Sep
Confidence becomes low for detail, but currently there is a likelihood of a spell of persistent, heavy rain, perhaps with strong to gale force northerly winds developing across summits.
Sun 21 Sep
Probably turning drier and brighter from the north with improving cloud bases and visibility. Strong to gale force northerly winds possible across 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.