Mountain weather
Eryri / Snowdonia
Confidence
Moderate for rain details on Wednesday. Low for timings of strongest winds and rain on Thursday and Friday.
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This eveningSunrise:Sunset:
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Wed 2 SepSunrise:Sunset:
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Thu 3 SepSunrise:Sunset:
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Further outlook
This evening forecast
Brightness fading as cloud thickens with showery rain by midnight.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
Poor Visibility
Heavy Persistent Rain
Gales
Severe Chill Effect
Strong Sunlight
Mountain weather forecast
Heavy rain slowly easing but staying damp and blustery with drizzle at times.
|
Time
|
Time |
00:00
|
03:00
|
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 |
90%
|
≥95%
|
≥95%
|
80%
|
70%
|
60%
|
40%
|
30%
|
Wind direction and speed
|
Time
|
Time |
00:00
|
03:00
|
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|---|---|
|
900m
|
900m | SW 25mph knots
SW
25mph |
SW 27mph knots
SW
27mph |
S 30mph knots
S
30mph |
SW 33mph knots
SW
33mph |
SW 28mph knots
SW
28mph |
SW 24mph knots
SW
24mph |
SW 26mph knots
SW
26mph |
SW 25mph knots
SW
25mph |
|
600m
|
600m | SW 16mph knots
SW
16mph |
SW 16mph knots
SW
16mph |
S 21mph knots
S
21mph |
SW 23mph knots
SW
23mph |
SW 20mph knots
SW
20mph |
SW 18mph knots
SW
18mph |
SW 16mph knots
SW
16mph |
SW 16mph knots
SW
16mph |
|
300m
|
300m | SW 10mph knots
SW
10mph |
SW 9mph knots
SW
9mph |
S 13mph knots
S
13mph |
SW 15mph knots
SW
15mph |
SW 14mph knots
SW
14mph |
SW 13mph knots
SW
13mph |
SW 11mph knots
SW
11mph |
SW 10mph knots
SW
10mph |
|
Valley
|
Valley | SW 10mph knots
SW
10mph |
SW 9mph knots
SW
9mph |
S 12mph knots
S
12mph |
SW 14mph knots
SW
14mph |
SW 13mph knots
SW
13mph |
SW 12mph knots
SW
12mph |
SW 10mph knots
SW
10mph |
S 10mph knots
S
10mph |
Wind gust
|
Time
|
Time |
00:00
|
03:00
|
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|---|---|
|
900m
|
900m | 30mph | 33mph | 37mph | 41mph | 36mph | 32mph | 33mph | 32mph |
|
600m
|
600m | 21mph | 21mph | 27mph | 30mph | 27mph | 26mph | 23mph | 23mph |
|
300m
|
300m | 19mph | 19mph | 24mph | 27mph | 25mph | 23mph | 21mph | 20mph |
|
Valley
|
Valley | 19mph | 18mph | 23mph | 25mph | 24mph | 21mph | 20mph | 20mph |
|
Time
|
Time |
00:00
|
03:00
|
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|---|---|
|
900m
|
900m | 10 degrees Celsius 10°C | 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 | 13 degrees Celsius 13°C | 12 degrees Celsius 12°C |
|
600m
|
600m | 12 degrees Celsius 12°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 | 15 degrees Celsius 15°C | 14 degrees Celsius 14°C |
|
300m
|
300m | 14 degrees Celsius 14°C | 14 degrees Celsius 14°C | 14 degrees Celsius 14°C | 16 degrees Celsius 16°C | 16 degrees Celsius 16°C | 17 degrees Celsius 17°C | 17 degrees Celsius 17°C | 16 degrees Celsius 16°C |
|
Valley
|
Valley | 15 degrees Celsius 15°C | 15 degrees Celsius 15°C | 15 degrees Celsius 15°C | 17 degrees Celsius 17°C | 18 degrees Celsius 18°C | 19 degrees Celsius 19°C | 18 degrees Celsius 18°C | 17 degrees Celsius 17°C |
| Freezing Level | Freezing Level |
2700m
|
2800m
|
3200m
|
3100m
|
3100m
|
3100m
|
3200m
|
3100m
|
|
Time
|
Time |
00:00
|
03:00
|
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|---|---|
|
900m
|
900m | 6 degrees Celsius 6°C | 6 degrees Celsius 6°C | 6 degrees Celsius 6°C | 7 degrees Celsius 7°C | 8 degrees Celsius 8°C | 9 degrees Celsius 9°C | 9 degrees Celsius 9°C | 8 degrees Celsius 8°C |
|
600m
|
600m | 9 degrees Celsius 9°C | 9 degrees Celsius 9°C | 9 degrees Celsius 9°C | 10 degrees Celsius 10°C | 11 degrees Celsius 11°C | 12 degrees Celsius 12°C | 12 degrees Celsius 12°C | 12 degrees Celsius 12°C |
|
300m
|
300m | 12 degrees Celsius 12°C | 12 degrees Celsius 12°C | 12 degrees Celsius 12°C | 14 degrees Celsius 14°C | 14 degrees Celsius 14°C | 15 degrees Celsius 15°C | 16 degrees Celsius 16°C | 15 degrees Celsius 15°C |
|
Valley
|
Valley | 14 degrees Celsius 14°C | 14 degrees Celsius 14°C | 14 degrees Celsius 14°C | 15 degrees Celsius 15°C | 16 degrees Celsius 16°C | 17 degrees Celsius 17°C | 17 degrees Celsius 17°C | 16 degrees Celsius 16°C |
| Freezing Level | Freezing Level |
2700m
|
2800m
|
3200m
|
3100m
|
3100m
|
3100m
|
3200m
|
3100m
|
Additional weather information
Meteorologist's view
A very wet start to the day with the potential for streams to rise rapidly and spate. Be prepared for surface water running over paths and slippery rock surfaces. Winds may gust close to 50 mph for a time over the highest summits during the morning, before easing and this will give considerable buffeting and make walking difficult in places. Waterproof and windproof clothing will be essential. Extensive hill fog will make route finding difficult and therefore the use of a compass and a map may be required for navigation.
Weather
Increasingly wet through the early hours with heavy rain developing, turning persistent by the end of the night. A very wet start to the morning but the rain easing by mid-morning and turning more showery. Occasional drier spells through the rest of the day, but frequent showers or spells of light drizzle, especially in the west. Glimmers of sunshine possible in eastern areas during the afternoon and evening.
Chance of cloud-free hill tops
10%, becoming 30% east.
Low cloud and visibility
Persistent and extensive cloud above 300-400m (400-600m in the east). This will give widespread fog and reduce visibility to poor or very poor. Occasional poor or very poor visibility at valley level too in periods of rain and drizzle but tending to become mostly good or very good visibility at lower levels later in the day.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
A somewhat drier day is currently anticipated with a few morning showers possible. Perhaps turning more generally wet by the evening. Occasional brighter intervals, mainly in the east.
Chance of cloud-free hill tops
30% becoming 60% in the east.
Maximum wind speed expected
Southwesterly 25 mph gusting 40 mph, easing then strengthening again by the evening.
Temperature
- At 800m Plus 11 Celsius.
- Valley Plus 15 Celsius rising to plus 19 Celsius.
- Freezing level Well above the summits.
Low cloud and visibility
Periods of cloud, persistent and extensive in the west, above 400-600m. Lifting to periods above 500-700m and locally clearing in the afternoon in the east. Often good or very good visibility at lower levels but widely poor or very poor in cloud with mist or fog and occasionally moderate in showers and evening rain,
Ground conditions
No recent ground conditions report available.
Mountain weather information
Fri 4 Sep
Overnight rain gradually clearing through the morning. Staying cloudy for a time but gradually brightening up later. Moderate to fresh westerly winds and turning cooler.
Sat 5 Sep
Largely dry with a mixture of cloud and sunny intervals. Some rain is possible later. Moderate westerly winds.
Sun 6 Sep
A lot of uncertainty but probably cloudy with rain at times, most persistent in the west. Fresh to strong southerly 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.