Mountain weather
Eryri / Snowdonia
Confidence
High for a changeable few days but moderate for extent and timing of early rain on Sunday.
-
Sun 6 SepSunrise:Sunset:
-
Mon 7 SepSunrise:Sunset:
-
Further outlook
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
Strong Sunlight
Poor Visibility
Thunderstorms
Mountain weather forecast
Showery rain clearing to bright or sunny spells. Windy at height.
|
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 |
80%
|
10%
|
10%
|
10%
|
10%
|
80%
|
Wind direction and speed
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | S 34mph knots
S
34mph |
S 41mph knots
S
41mph |
S 44mph knots
S
44mph |
SW 41mph knots
SW
41mph |
SW 37mph knots
SW
37mph |
SW 35mph knots
SW
35mph |
|
600m
|
600m | S 27mph knots
S
27mph |
S 28mph knots
S
28mph |
S 31mph knots
S
31mph |
S 29mph knots
S
29mph |
SW 21mph knots
SW
21mph |
SW 22mph knots
SW
22mph |
|
300m
|
300m | S 17mph knots
S
17mph |
S 20mph knots
S
20mph |
S 21mph knots
S
21mph |
S 19mph knots
S
19mph |
S 14mph knots
S
14mph |
SW 13mph knots
SW
13mph |
|
Valley
|
Valley | S 17mph knots
S
17mph |
S 20mph knots
S
20mph |
S 21mph knots
S
21mph |
S 18mph knots
S
18mph |
S 14mph knots
S
14mph |
SW 13mph knots
SW
13mph |
Wind gust
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | 41mph | 48mph | 53mph | 50mph | 44mph | 42mph |
|
600m
|
600m | 35mph | 34mph | 39mph | 36mph | 28mph | 28mph |
|
300m
|
300m | 32mph | 33mph | 34mph | 31mph | 26mph | 24mph |
|
Valley
|
Valley | 32mph | 33mph | 33mph | 30mph | 25mph | 24mph |
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | ||||||
|
600m
|
600m | ||||||
|
300m
|
300m | ||||||
|
Valley
|
Valley | ||||||
| Freezing Level | Freezing Level |
3600m
|
3500m
|
3400m
|
3200m
|
3200m
|
3300m
|
Additional weather information
Meteorologist's view
A fine day for hill walking but remember some extra layers if you are heading to the summits as it will feel cool in the windy conditions on the highest peaks. Strong winds may affect balance on hills from mid-level slopes upwards.
Weather
Showery rain is possible at first with a small chance of isolated embedded thunderstorms, but forecast to clear by mid-morning. Thereafter another fine, dry day is expected with a mixture of cloud and sunny spells as well as gusty winds at higher elevations. Cloud increasing from the west during the evening with further outbreaks of rain arriving before midnight.
Chance of cloud-free hill tops
40% rising to 80% from late-morning before lowering again towards 20% through the evening.
Low cloud and visibility
Occasional patches of cloud above 500-600m at first, especially in the west. Prolonged periods without any low cloud during the daytime, although occasional cloud banks affecting the very highest summits in the afternoon. Cloud above 400-600m turning more persistent after dark this evening. Poor or very poor visibility in the cloud and occasionally moderate at most levels in the rain or drizzle. Otherwise often good, albeit probably hazier than on Saturday.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Outbreaks of rain will move across the park during the early hours, some heavier bursts are likely. Cloudy during the day with bright or sunny spells developing. A band of squally rain is likely from mid-afternoon, with some heavy and possibly thundery bursts.
Chance of cloud-free hill tops
50% rising to 70% from early-morning, before reducing to 50% later until the evening.
Maximum wind speed expected
Southwesterly 20-25mph, gusting 35-45 mph
Temperature
- At 800m Plus 11 Celsius rising to plus 16 Celsius.
- Valley Plus 12 Celsius rising to plus 20 Celsius.
- Freezing level Well above the summits.
Low cloud and visibility
Cloud bases close to 500m during the early hours, but these lifting by mid-morning, leaving most summits cloud free. However cloud bases likely to descend again during the evening. Poor or very poor visibility in the cloud and occasionally moderate at most levels in the rain. Otherwise often good
Ground conditions
No recent ground conditions report available.
Mountain weather information
Tue 8 Sep
Overnight rain may linger into the morning before turning brighter with sunny spells and frequent blustery showers. Feeling cooler in the fresh to strong westerly, then northwesterly winds.
Wed 9 Sep
Still breezy but not as windy with moderate northwesterly winds gradually easing. Rather cloudy but mainly dry with sunny spells. Feeling cool.
Thu 10 Sep
Remaining changeable with cloud and rain moving eastwards during the day. Becoming rather breezy. Temperatures near average.
Mountain weather information
Tue 8 Sep
Overnight rain may linger into the morning before turning brighter with sunny spells and frequent blustery showers. Feeling cooler in the fresh to strong westerly, then northwesterly winds.
Wed 9 Sep
Still breezy but not as windy with moderate northwesterly winds gradually easing. Rather cloudy but mainly dry with sunny spells. Feeling cool.
Thu 10 Sep
Remaining changeable with cloud and rain moving eastwards during the day. Becoming rather breezy. Temperatures near average.
Summit specific forecast
Mountain summits
Other points of interest
Cluster of multiple stations