Mountain weather
Eryri / Snowdonia
Confidence
Moderate for details of low cloud and rain/drizzle on Friday. High for Saturday. Moderate for arrival time of rain and stronger winds on Sunday.
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This eveningSunrise:Sunset:
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Fri 25 SepSunrise:Sunset:
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Sat 26 SepSunrise:Sunset:
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Further outlook
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
Poor Visibility
Heavy Persistent Rain
Mountain weather forecast
Often damp with rain at times, turning drier later
|
Time
|
Time |
00:00
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03:00
|
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
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|---|---|---|---|---|---|---|---|---|---|
|
Weather
(at 800m)
|
Weather symbols | ||||||||
|
Chance of
precipitation (at 800m)
|
Chance of precipitation |
10%
|
60%
|
70%
|
80%
|
90%
|
60%
|
20%
|
10%
|
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 23mph knots
SW
23mph |
SW 25mph knots
SW
25mph |
SW 26mph knots
SW
26mph |
SW 25mph knots
SW
25mph |
SW 25mph knots
SW
25mph |
SW 24mph knots
SW
24mph |
SW 23mph knots
SW
23mph |
S 20mph knots
S
20mph |
|
600m
|
600m | SW 12mph knots
SW
12mph |
SW 14mph knots
SW
14mph |
SW 15mph knots
SW
15mph |
SW 18mph knots
SW
18mph |
SW 19mph knots
SW
19mph |
SW 19mph knots
SW
19mph |
SW 16mph knots
SW
16mph |
S 14mph knots
S
14mph |
|
300m
|
300m | S 7mph knots
S
7mph |
SW 8mph knots
SW
8mph |
SW 9mph knots
SW
9mph |
SW 13mph knots
SW
13mph |
SW 15mph knots
SW
15mph |
SW 16mph knots
SW
16mph |
SW 13mph knots
SW
13mph |
S 11mph knots
S
11mph |
|
Valley
|
Valley | S 7mph knots
S
7mph |
SW 8mph knots
SW
8mph |
SW 8mph knots
SW
8mph |
SW 12mph knots
SW
12mph |
SW 15mph knots
SW
15mph |
SW 15mph knots
SW
15mph |
S 11mph knots
S
11mph |
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 | 28mph | 30mph | 32mph | 32mph | 34mph | 34mph | 31mph | 28mph |
|
600m
|
600m | 18mph | 19mph | 22mph | 25mph | 29mph | 29mph | 24mph | 21mph |
|
300m
|
300m | 16mph | 17mph | 19mph | 22mph | 27mph | 28mph | 22mph | 19mph |
|
Valley
|
Valley | 16mph | 17mph | 18mph | 21mph | 25mph | 26mph | 21mph | 18mph |
|
Time
|
Time |
00:00
|
03:00
|
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|---|---|
|
900m
|
900m | 7 degrees Celsius 7°C | 7 degrees Celsius 7°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 | 7 degrees Celsius 7°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 | 11 degrees Celsius 11°C | 10 degrees Celsius 10°C | 9 degrees Celsius 9°C |
|
300m
|
300m | 11 degrees Celsius 11°C | 11 degrees Celsius 11°C | 11 degrees Celsius 11°C | 13 degrees Celsius 13°C | 14 degrees Celsius 14°C | 14 degrees Celsius 14°C | 12 degrees Celsius 12°C | 11 degrees Celsius 11°C |
|
Valley
|
Valley | 12 degrees Celsius 12°C | 12 degrees Celsius 12°C | 12 degrees Celsius 12°C | 15 degrees Celsius 15°C | 16 degrees Celsius 16°C | 16 degrees Celsius 16°C | 14 degrees Celsius 14°C | 13 degrees Celsius 13°C |
| Freezing Level | Freezing Level |
1800m
|
1800m
|
1900m
|
1900m
|
2000m
|
2000m
|
2100m
|
2100m
|
|
Time
|
Time |
00:00
|
03:00
|
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|---|---|
|
900m
|
900m | 2 degrees Celsius 2°C | 2 degrees Celsius 2°C | 2 degrees Celsius 2°C | 3 degrees Celsius 3°C | 4 degrees Celsius 4°C | 4 degrees Celsius 4°C | 3 degrees Celsius 3°C | 3 degrees Celsius 3°C |
|
600m
|
600m | 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 | 8 degrees Celsius 8°C | 7 degrees Celsius 7°C | 6 degrees Celsius 6°C |
|
300m
|
300m | 9 degrees Celsius 9°C | 9 degrees Celsius 9°C | 9 degrees Celsius 9°C | 11 degrees Celsius 11°C | 11 degrees Celsius 11°C | 11 degrees Celsius 11°C | 10 degrees Celsius 10°C | 9 degrees Celsius 9°C |
|
Valley
|
Valley | 11 degrees Celsius 11°C | 10 degrees Celsius 10°C | 11 degrees Celsius 11°C | 13 degrees Celsius 13°C | 13 degrees Celsius 13°C | 13 degrees Celsius 13°C | 12 degrees Celsius 12°C | 11 degrees Celsius 11°C |
| Freezing Level | Freezing Level |
1800m
|
1800m
|
1900m
|
1900m
|
2000m
|
2000m
|
2100m
|
2100m
|
Additional weather information
Meteorologist's view
Visibility will be poor at times on Friday so ensure you take a map and compass and know how to use them to stay safe and navigate to your destination. Waterproofs will also be useful as the morning will often be wet.
Weather
Periods of mostly light rain and drizzle, locally heavy first thing. Turning drier later in the afternoon but staying generally cloudy.
Chance of cloud-free hill tops
10% becoming 70% by late afternoon.
Low cloud and visibility
Often prolonged periods of cloud above 700-800m with cloud lowering to shroud slopes above 400-500m during the morning rain. Cloud lifting and clearing to become patches above 700m through the afternoon and mostly clearing by the evening. Very poor visibility in the cloud/fog and temporarily poor at lower levels as the rain moves in later. Otherwise generally good during the drier periods.
Ground conditions
No recent ground conditions report available.
Mountain weather information
Weather
Isolated shallow fog patches clearing quite readily after dawn to leave a fine day with some sunshine at times. Skies may periodically cloud over but there will continue to be some lengthy sunny periods.
Chance of cloud-free hill tops
90%
Maximum wind speed expected
Westerly or southwesterly 15-25 mph
Temperature
- At 800m Plus 6 Celsius rising to plus 10 Celsius.
- Valley Plus 3 Celsius rising to plus 19 Celsius.
- Freezing level Well above the summits.
Low cloud and visibility
Patches of cloud may form around 800m for a time before lifting above the summits. Otherwise the higher cloud will be a long way above the summits. Locally very poor visibility in early valley fog and briefly poor in cloud/hill fog but otherwise very good visibility.
Ground conditions
No recent ground conditions report available.
Mountain weather information
Sun 27 Sep
After a dry start with some early sunshine, soon turning cloudy, windy and increasingly wet. Some heavy rain is likely through the middle of the day before perhaps turning drier by the end of the evening. Strong southerly winds with possible summit gales, veering westerly later.
Mon 28 Sep
High pressure building to bring a dry day with sunny periods once early valley fog clears. Light to moderate southeasterly winds developing.
Tue 29 Sep
Strengthening southerly or southeasterly winds with possible summit gales later. Probably staying dry through daylight hours but heavy rain is possible by the evening.
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.