Mountain weather
Eryri / Snowdonia
Confidence
Generally high but moderate for details of rain on Sunday and moderate for strength of winds on Tuesday.
-
Sun 27 SepSunrise:Sunset:
-
Mon 28 SepSunrise:Sunset:
-
Further outlook
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
Poor Visibility
Gales
Heavy Persistent Rain
Strong Sunlight
Mountain weather forecast
Turning wet and windy through the morning but clearing later.
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
Weather
(at 800m)
|
Weather symbols | ||||||
|
Chance of
precipitation (at 800m)
|
Chance of precipitation |
30%
|
≥95%
|
≥95%
|
60%
|
30%
|
10%
|
Wind direction and speed
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | SE 38mph knots
SE
38mph |
SE 51mph knots
SE
51mph |
S 49mph knots
S
49mph |
W 28mph knots
W
28mph |
W 19mph knots
W
19mph |
W 18mph knots
W
18mph |
|
600m
|
600m | S 25mph knots
S
25mph |
SE 33mph knots
SE
33mph |
S 33mph knots
S
33mph |
W 20mph knots
W
20mph |
W 9mph knots
W
9mph |
SW 10mph knots
SW
10mph |
|
300m
|
300m | S 16mph knots
S
16mph |
SE 22mph knots
SE
22mph |
S 21mph knots
S
21mph |
W 14mph knots
W
14mph |
SW 4mph knots
SW
4mph |
SW 6mph knots
SW
6mph |
|
Valley
|
Valley | S 16mph knots
S
16mph |
SE 22mph knots
SE
22mph |
S 20mph knots
S
20mph |
W 14mph knots
W
14mph |
SW 4mph knots
SW
4mph |
SW 6mph knots
SW
6mph |
Wind gust
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | 44mph | 59mph | 59mph | 35mph | 22mph | 22mph |
|
600m
|
600m | 31mph | 40mph | 43mph | 26mph | 12mph | 14mph |
|
300m
|
300m | 30mph | 37mph | 37mph | 24mph | 10mph | 12mph |
|
Valley
|
Valley | 30mph | 37mph | 36mph | 23mph | 10mph | 13mph |
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | 7 degrees Celsius 7°C | 8 degrees Celsius 8°C | 11 degrees Celsius 11°C | 8 degrees Celsius 8°C | 7 degrees Celsius 7°C | 7 degrees Celsius 7°C |
|
600m
|
600m | 10 degrees Celsius 10°C | 10 degrees Celsius 10°C | 13 degrees Celsius 13°C | 10 degrees Celsius 10°C | 10 degrees Celsius 10°C | 9 degrees Celsius 9°C |
|
300m
|
300m | 12 degrees Celsius 12°C | 12 degrees Celsius 12°C | 15 degrees Celsius 15°C | 13 degrees Celsius 13°C | 12 degrees Celsius 12°C | 11 degrees Celsius 11°C |
|
Valley
|
Valley | 13 degrees Celsius 13°C | 14 degrees Celsius 14°C | 16 degrees Celsius 16°C | 14 degrees Celsius 14°C | 13 degrees Celsius 13°C | 12 degrees Celsius 12°C |
| Freezing Level | Freezing Level |
2700m
|
3100m
|
3000m
|
2200m
|
1700m
|
1700m
|
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | 1 degrees Celsius 1°C | 2 degrees Celsius 2°C | 5 degrees Celsius 5°C | 3 degrees Celsius 3°C | 3 degrees Celsius 3°C | 3 degrees Celsius 3°C |
|
600m
|
600m | 6 degrees Celsius 6°C | 6 degrees Celsius 6°C | 8 degrees Celsius 8°C | 7 degrees Celsius 7°C | 8 degrees Celsius 8°C | 7 degrees Celsius 7°C |
|
300m
|
300m | 9 degrees Celsius 9°C | 9 degrees Celsius 9°C | 11 degrees Celsius 11°C | 10 degrees Celsius 10°C | 11 degrees Celsius 11°C | 10 degrees Celsius 10°C |
|
Valley
|
Valley | 10 degrees Celsius 10°C | 10 degrees Celsius 10°C | 13 degrees Celsius 13°C | 12 degrees Celsius 12°C | 13 degrees Celsius 13°C | 11 degrees Celsius 11°C |
| Freezing Level | Freezing Level |
2700m
|
3100m
|
3000m
|
2200m
|
1700m
|
1700m
|
Additional weather information
Meteorologist's view
A rather challenging start to the day for outdoor activities in the national park. Patchy low cloud and persistent heavy rain will make for challenging navigation and for slippery conditions underfoot. Waterproof clothing is recommended. Through the afternoon conditions are expected to improve with drier and brighter skies. UV levels will be low through the day due to cloud amounts.
Weather
Patchy light rain at first with low cloud and areas of hill fog. Becoming increasingly wet and windy through Sunday morning with the heaviest rain from mid morning until the middle of the afternoon. Becoming dry towards the late afternoon with sunny spells and an easing wind.
Chance of cloud-free hill tops
20% becoming 90% from late afternoon.
Low cloud and visibility
Patches of cloud developing above 600m through the morning, becoming periods above 400-500m from the late morning, especially in association with more prolonged periods of rain. Lifting to above the summits from late afternoon as rain and cloud clears east. Often poor in the rain and very poor in cloud/hill fog but good ahead of the rain in the morning and again late afternoon.
Ground conditions
No recent ground conditions report available.
Mountain weather information
Weather
High pressure will bring a mostly dry day with lengthy sunny periods, once any early isolated mist and valley fog has cleared. Light northwesterly winds becoming light to moderate easterly.
Chance of cloud-free hill tops
>95%
Maximum wind speed expected
Southerly 10-15 mph.
Temperature
- At 800m Plus 4 Celsius rising to plus 8 Celsius.
- Valley Plus 11 Celsius rising to plus 15 Celsius.
- Freezing level Above summits.
Low cloud and visibility
Initially there may be some isolated mist and valley fog in prone locations, this is expected to quickly clear. All cloud is expected to be above summits throughout the day. Poor or very poor visibility in mist or valley fog initially but once cleared no visibility issues are expected. Views of distant peaks possible.
Ground conditions
No recent ground conditions report available.
Mountain weather information
Tue 29 Sep
Turning unsettled and windy with strong southeasterly winds developing and a chance of summit gales later. Hill fog and occasional showery rain with potentially heavier rain later.
Wed 30 Sep
Overnight rain clearing around dawn to leave a bright and breezy day with sunny spells and a few showers. Fresh to strong southerly winds.
Thu 1 Oct
Another rather breezy day ahead with bright or sunny spells as well as scattered showers.
Mountain weather information
Tue 29 Sep
Turning unsettled and windy with strong southeasterly winds developing and a chance of summit gales later. Hill fog and occasional showery rain with potentially heavier rain later.
Wed 30 Sep
Overnight rain clearing around dawn to leave a bright and breezy day with sunny spells and a few showers. Fresh to strong southerly winds.
Thu 1 Oct
Another rather breezy day ahead with bright or sunny spells as well as scattered showers.
Summit specific forecast
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.