Mountain weather
Eryri / Snowdonia
Confidence
High confidence for a changeable theme. Lower for intensity of rainfall and clearance especially early Tuesday.
-
Mon 7 SepSunrise:Sunset:
-
Tue 8 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
Strong Sunlight
Gales
Severe Chill Effect
Heavy Persistent Rain
Mountain weather forecast
Early low cloud and rain clearing to sunshine. Further rain arriving 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%
|
10%
|
10%
|
10%
|
60%
|
90%
|
Wind direction and speed
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | W 20mph knots
W
20mph |
W 19mph knots
W
19mph |
SW 23mph knots
SW
23mph |
SW 32mph knots
SW
32mph |
SW 39mph knots
SW
39mph |
SW 31mph knots
SW
31mph |
|
600m
|
600m | W 12mph knots
W
12mph |
W 15mph knots
W
15mph |
SW 19mph knots
SW
19mph |
SW 26mph knots
SW
26mph |
SW 26mph knots
SW
26mph |
SW 21mph knots
SW
21mph |
|
300m
|
300m | W 6mph knots
W
6mph |
W 10mph knots
W
10mph |
SW 14mph knots
SW
14mph |
SW 18mph knots
SW
18mph |
SW 17mph knots
SW
17mph |
SW 13mph knots
SW
13mph |
|
Valley
|
Valley | W 6mph knots
W
6mph |
W 10mph knots
W
10mph |
SW 14mph knots
SW
14mph |
SW 18mph knots
SW
18mph |
SW 16mph knots
SW
16mph |
SW 12mph knots
SW
12mph |
Wind gust
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | 24mph | 24mph | 30mph | 41mph | 48mph | 39mph |
|
600m
|
600m | 16mph | 20mph | 25mph | 34mph | 34mph | 28mph |
|
300m
|
300m | 14mph | 17mph | 23mph | 31mph | 31mph | 25mph |
|
Valley
|
Valley | 14mph | 17mph | 22mph | 30mph | 30mph | 24mph |
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | 8 degrees Celsius 8°C | 8 degrees Celsius 8°C | 9 degrees Celsius 9°C | 9 degrees Celsius 9°C | 9 degrees Celsius 9°C | 8 degrees Celsius 8°C |
|
600m
|
600m | 10 degrees Celsius 10°C | 11 degrees Celsius 11°C | 12 degrees Celsius 12°C | 12 degrees Celsius 12°C | 11 degrees Celsius 11°C | 10 degrees Celsius 10°C |
|
300m
|
300m | 13 degrees Celsius 13°C | 13 degrees Celsius 13°C | 14 degrees Celsius 14°C | 15 degrees Celsius 15°C | 14 degrees Celsius 14°C | 12 degrees Celsius 12°C |
|
Valley
|
Valley | 14 degrees Celsius 14°C | 15 degrees Celsius 15°C | 16 degrees Celsius 16°C | 16 degrees Celsius 16°C | 15 degrees Celsius 15°C | 14 degrees Celsius 14°C |
| Freezing Level | Freezing Level |
2100m
|
2000m
|
1900m
|
2400m
|
2500m
|
2200m
|
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | 4 degrees Celsius 4°C | 4 degrees Celsius 4°C | 5 degrees Celsius 5°C | 4 degrees Celsius 4°C | 4 degrees Celsius 4°C | 3 degrees Celsius 3°C |
|
600m
|
600m | 8 degrees Celsius 8°C | 8 degrees Celsius 8°C | 8 degrees Celsius 8°C | 8 degrees Celsius 8°C | 7 degrees Celsius 7°C | 6 degrees Celsius 6°C |
|
300m
|
300m | 12 degrees Celsius 12°C | 12 degrees Celsius 12°C | 12 degrees Celsius 12°C | 12 degrees Celsius 12°C | 11 degrees Celsius 11°C | 10 degrees Celsius 10°C |
|
Valley
|
Valley | 13 degrees Celsius 13°C | 13 degrees Celsius 13°C | 13 degrees Celsius 13°C | 13 degrees Celsius 13°C | 13 degrees Celsius 13°C | 12 degrees Celsius 12°C |
| Freezing Level | Freezing Level |
2100m
|
2000m
|
1900m
|
2400m
|
2500m
|
2200m
|
Additional weather information
Meteorologist's view
A day for layers. A pleasant day in the late morning and afternoon with Moderate UV levels, although despite the sunny spells it will feel cold in the wind. Note the deterioration in conditions from late afternoon, with waterproofs becoming necessary and navigation conditions becoming more challenging. Risk of gales on higher summits later.
Weather
A dull start with low cloud, hill fog and rain. This soon clearing with sunny spells developing. Cloud will increase from late afternoon with outbreaks of occasionally heavy rain moving southeastwards early evening.
Chance of cloud-free hill tops
20% rising to 80% by mid to late morning, dropping back to 30% from late afternoon.
Low cloud and visibility
Cloud bases 400-600m at first, but lifting by mid to late morning, leaving all but the highest summits cloud free. However, cloud bases likely to descend again late afternoon. Poor or very poor visibility in the cloud and moderate to poor in rain. Otherwise, visibility generally good.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Wet overnight but rain clearing before dawn to leave sunny spells through much of the day. The odd shower is still possible, these most likely during the afternoon and evening.
Chance of cloud-free hill tops
30% overnight, quickly rising to 80%
Maximum wind speed expected
Westerly 20-25 mph gusting 30-40 mph.
Temperature
- At 800m Plus 7 Celsius.
- Valley Plus 10 Celsius rising to plus 15 Celsius.
- Freezing level Above summits.
Low cloud and visibility
Early low cloud with bases above 500m soon lifting. Thereafter mostly above summits. Moderate to poor visibility in the heavy rain or showers, and very poor in low cloud, but otherwise excellent.
Ground conditions
No recent ground conditions report available.
Mountain weather information
Wed 9 Sep
A fresh start leading to a mostly dry day with sunny spells but a risk of isolated showers. Moderate northwesterly winds.
Thu 10 Sep
Low cloud with outbreaks of rain arriving from the west. Fresh to strong southerly or southwesterly winds.
Fri 11 Sep
Rain clearing early but becoming dry and often cloudy, although some sunny spells are possible. Light to moderate westerly or northwesterly winds.
Mountain weather information
Wed 9 Sep
A fresh start leading to a mostly dry day with sunny spells but a risk of isolated showers. Moderate northwesterly winds.
Thu 10 Sep
Low cloud with outbreaks of rain arriving from the west. Fresh to strong southerly or southwesterly winds.
Fri 11 Sep
Rain clearing early but becoming dry and often cloudy, although some sunny spells are possible. Light to moderate westerly or northwesterly 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.