Mountain weather
Eryri / Snowdonia
Confidence
High for overall changeable theme but low for intensity and clearance of rain on Saturday.
-
Sat 12 SepSunrise:Sunset:
-
Sun 13 SepSunrise:Sunset:
-
Further outlook
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
Severe Chill Effect
Mountain weather forecast
Wet and very windy today. Gales expected on higher slopes and ridges.
|
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 |
40%
|
90%
|
≥95%
|
90%
|
70%
|
50%
|
Wind direction and speed
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | SW 44mph knots
SW
44mph |
SW 45mph knots
SW
45mph |
SW 41mph knots
SW
41mph |
SW 35mph knots
SW
35mph |
SW 29mph knots
SW
29mph |
W 21mph knots
W
21mph |
|
600m
|
600m | SW 29mph knots
SW
29mph |
SW 30mph knots
SW
30mph |
SW 25mph knots
SW
25mph |
SW 23mph knots
SW
23mph |
SW 19mph knots
SW
19mph |
W 14mph knots
W
14mph |
|
300m
|
300m | S 18mph knots
S
18mph |
SW 19mph knots
SW
19mph |
SW 16mph knots
SW
16mph |
SW 14mph knots
SW
14mph |
SW 12mph knots
SW
12mph |
SW 8mph knots
SW
8mph |
|
Valley
|
Valley | S 18mph knots
S
18mph |
SW 18mph knots
SW
18mph |
SW 16mph knots
SW
16mph |
SW 14mph knots
SW
14mph |
SW 11mph knots
SW
11mph |
SW 8mph knots
SW
8mph |
Wind gust
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | 52mph | 53mph | 50mph | 42mph | 35mph | 26mph |
|
600m
|
600m | 36mph | 38mph | 34mph | 30mph | 25mph | 19mph |
|
300m
|
300m | 33mph | 33mph | 31mph | 26mph | 23mph | 16mph |
|
Valley
|
Valley | 33mph | 33mph | 30mph | 25mph | 21mph | 15mph |
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | 10 degrees Celsius 10°C | 11 degrees Celsius 11°C | 12 degrees Celsius 12°C | 13 degrees Celsius 13°C | 13 degrees Celsius 13°C | 12 degrees Celsius 12°C |
|
600m
|
600m | 12 degrees Celsius 12°C | 13 degrees Celsius 13°C | 14 degrees Celsius 14°C | 14 degrees Celsius 14°C | 14 degrees Celsius 14°C | 14 degrees Celsius 14°C |
|
300m
|
300m | 14 degrees Celsius 14°C | 15 degrees Celsius 15°C | 16 degrees Celsius 16°C | 16 degrees Celsius 16°C | 16 degrees Celsius 16°C | 15 degrees Celsius 15°C |
|
Valley
|
Valley | 15 degrees Celsius 15°C | 16 degrees Celsius 16°C | 17 degrees Celsius 17°C | 17 degrees Celsius 17°C | 17 degrees Celsius 17°C | 16 degrees Celsius 16°C |
| Freezing Level | Freezing Level |
3500m
|
3800m
|
3600m
|
3200m
|
2700m
|
2700m
|
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | 5 degrees Celsius 5°C | 6 degrees Celsius 6°C | 6 degrees Celsius 6°C | 8 degrees Celsius 8°C | 8 degrees Celsius 8°C | 9 degrees Celsius 9°C |
|
600m
|
600m | 8 degrees Celsius 8°C | 8 degrees Celsius 8°C | 10 degrees Celsius 10°C | 11 degrees Celsius 11°C | 11 degrees Celsius 11°C | 12 degrees Celsius 12°C |
|
300m
|
300m | 11 degrees Celsius 11°C | 12 degrees Celsius 12°C | 13 degrees Celsius 13°C | 14 degrees Celsius 14°C | 14 degrees Celsius 14°C | 15 degrees Celsius 15°C |
|
Valley
|
Valley | 12 degrees Celsius 12°C | 13 degrees Celsius 13°C | 14 degrees Celsius 14°C | 16 degrees Celsius 16°C | 16 degrees Celsius 16°C | 16 degrees Celsius 16°C |
| Freezing Level | Freezing Level |
3500m
|
3800m
|
3600m
|
3200m
|
2700m
|
2700m
|
Additional weather information
Meteorologist's view
Very wet and windy today with waterproofs essential. Gale force gusts especially on high summits will make extremely difficult walking conditions and exacerbate wind chill.
Weather
Overcast with patchy rain or drizzle at first but rain soon turning persistent and heavier from the north by mid-morning, accompanied by generally strong winds and upland gales. Rain continuing well into the afternoon, perhaps turning patchier and lighter later towards the evening. Strongest winds slowly abating.
Chance of cloud-free hill tops
20%, though nil in west from mid-morning.
Low cloud and visibility
Widespread cloud bases 400-500m, patches down to 200-300m, especially across western facing hills from mid-morning. Highest bases in the east. Moderate to poor visibility in rain, very poor in low cloud.
Ground conditions
No recent ground conditions report available.
Mountain weather information
Weather
Further rain or drizzle expected overnight, with a small chance of becoming more persistent for a time. A damp start with hill fog through the early hours. Conditions improving with sunnier spells likely, especially in the north of the Park by the afternoon, but low cloud likely persisting much of the day in the west. Much lighter winds.
Chance of cloud-free hill tops
20% early on, soon 60% to the northeast.
Maximum wind speed expected
West or southwesterly 10-15 mph.
Temperature
- At 800m Plus 8 Celsius rising to plus 11 Celsius
- Valley Plus 15 Celsius rising to plus 18 Celsius
- Freezing level Above summits.
Low cloud and visibility
Low cloud and hill fog lifting and breaking by the afternoon in the northeast, cloud shrouding summits in the west. Good visibility outside rain and low cloud, otherwise generally poor.
Ground conditions
No recent ground conditions report available.
Mountain weather information
Mon 14 Sep
Staying largely cloudy with hill fog and drizzle in the morning. More persistent rain expected later. Moderate to fresh southwesterly winds. Freezing levels above summits on all outlook days.
Tue 15 Sep
Overnight rain clearing to leave sunny spells and isolated showers. Feeling fresher. Strong westerly winds.
Wed 16 Sep
Some bright spells with isolated showers. Chance of persistent rain later. Moderate to fresh west or southwesterly winds.
Mountain weather information
Mon 14 Sep
Staying largely cloudy with hill fog and drizzle in the morning. More persistent rain expected later. Moderate to fresh southwesterly winds. Freezing levels above summits on all outlook days.
Tue 15 Sep
Overnight rain clearing to leave sunny spells and isolated showers. Feeling fresher. Strong westerly winds.
Wed 16 Sep
Some bright spells with isolated showers. Chance of persistent rain later. Moderate to fresh west or southwesterly winds.
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.