Mountain weather
Eryri / Snowdonia
Confidence
High for continued changeable conditions. Low with respect to shower distribution and intensity.
-
Wed 16 SepSunrise:Sunset:
-
Thu 17 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
Mountain weather forecast
Sunshine and showers through the day. Low cloud and patchy rain arriving during the evening.
|
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 |
50%
|
40%
|
40%
|
30%
|
30%
|
40%
|
Wind direction and speed
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | NW 23mph knots
NW
23mph |
W 18mph knots
W
18mph |
W 18mph knots
W
18mph |
W 19mph knots
W
19mph |
SW 27mph knots
SW
27mph |
SW 32mph knots
SW
32mph |
|
600m
|
600m | NW 16mph knots
NW
16mph |
NW 13mph knots
NW
13mph |
W 14mph knots
W
14mph |
W 15mph knots
W
15mph |
SW 18mph knots
SW
18mph |
SW 20mph knots
SW
20mph |
|
300m
|
300m | NW 11mph knots
NW
11mph |
NW 10mph knots
NW
10mph |
W 10mph knots
W
10mph |
W 10mph knots
W
10mph |
SW 11mph knots
SW
11mph |
SW 13mph knots
SW
13mph |
|
Valley
|
Valley | NW 11mph knots
NW
11mph |
NW 10mph knots
NW
10mph |
W 11mph knots
W
11mph |
W 10mph knots
W
10mph |
SW 10mph knots
SW
10mph |
SW 12mph knots
SW
12mph |
Wind gust
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | 28mph | 23mph | 23mph | 25mph | 34mph | 40mph |
|
600m
|
600m | 20mph | 17mph | 18mph | 20mph | 24mph | 28mph |
|
300m
|
300m | 19mph | 17mph | 17mph | 18mph | 21mph | 26mph |
|
Valley
|
Valley | 20mph | 17mph | 17mph | 17mph | 20mph | 24mph |
|
Time
|
Time |
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 | 7 degrees Celsius 7°C | 7 degrees Celsius 7°C | 8 degrees Celsius 8°C |
|
600m
|
600m | 9 degrees Celsius 9°C | 9 degrees Celsius 9°C | 10 degrees Celsius 10°C | 10 degrees Celsius 10°C | 10 degrees Celsius 10°C | 10 degrees Celsius 10°C |
|
300m
|
300m | 11 degrees Celsius 11°C | 12 degrees Celsius 12°C | 12 degrees Celsius 12°C | 12 degrees Celsius 12°C | 12 degrees Celsius 12°C | 12 degrees Celsius 12°C |
|
Valley
|
Valley | 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 |
| Freezing Level | Freezing Level |
2000m
|
1900m
|
1900m
|
1900m
|
1900m
|
2300m
|
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | 3 degrees Celsius 3°C | 3 degrees Celsius 3°C | 3 degrees Celsius 3°C | 3 degrees Celsius 3°C | 2 degrees Celsius 2°C | 2 degrees Celsius 2°C |
|
600m
|
600m | 6 degrees Celsius 6°C | 6 degrees Celsius 6°C | 7 degrees Celsius 7°C | 7 degrees Celsius 7°C | 6 degrees Celsius 6°C | 6 degrees Celsius 6°C |
|
300m
|
300m | 9 degrees Celsius 9°C | 10 degrees Celsius 10°C | 10 degrees Celsius 10°C | 11 degrees Celsius 11°C | 10 degrees Celsius 10°C | 10 degrees Celsius 10°C |
|
Valley
|
Valley | 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 | 12 degrees Celsius 12°C |
| Freezing Level | Freezing Level |
2000m
|
1900m
|
1900m
|
1900m
|
1900m
|
2300m
|
Additional weather information
Meteorologist's view
Potentially tricky conditions to start the day with poor navigation conditions during the morning and across the highest peaks but improving as the day progresses. Despite the cool temperatures, high UV levels developing during the afternoon as the cloud breaks later.
Weather
Widely cloudy through the morning with showers possible across the park. Cloud lifts and breaks through the day with sunny spells developing and showers becoming more isolated. Cloud thickens through the evening with outbreaks of rain developing into the evening and through the night.
Chance of cloud-free hill tops
30% rising to 70% by mid-afternoon.
Low cloud and visibility
Widespread cloud initially between 500-700m, particularly for western and northern areas, cloud becomes scattered with bases will lift to around 800-1000m by the afternoon. Generally, very good or excellent visibilities below any cloud but poor to very poor in hill fog. Moderate visibilities in any passing showers.
Ground conditions
No recent ground conditions report available.
Mountain weather information
Weather
Damp through the early hours with rain clearing by mid-morning. Sunny spells following behind with further showers possible. Clear skies into the night. Fresh, blustery westerly winds.
Chance of cloud-free hill tops
40% soon rising to 90% by mid-morning.
Maximum wind speed expected
Westerly 15-20 mph gusting 25-30 mph, potentially 35 mph over the summits.
Temperature
- At 800m Plus 5 Celsius rising to plus 7 Celsius.
- Valley Plus 13 Celsius rising to plus 15 Celsius.
- Freezing level Above summits.
Low cloud and visibility
Low cloud initially with bases around 400-600 m but soon clearing to leave cloud largely above summits. Poor visibilities then rising to excellent in clear airmass.
Ground conditions
No recent ground conditions report available.
Mountain weather information
Fri 18 Sep
Fresh start with sunny spells. Cloud increasing with rain arriving by the afternoon. Moderate to fresh, gusty south-westerly winds.
Sat 19 Sep
A drizzly and cloudy day, extensive hill fog likely with fresh westerly winds.
Sun 20 Sep
Dull initially but cloud breaking away from windward hills to leave a reasonable day, particularly for eastern areas. Lighter north-westerly winds.
Mountain weather information
Fri 18 Sep
Fresh start with sunny spells. Cloud increasing with rain arriving by the afternoon. Moderate to fresh, gusty south-westerly winds.
Sat 19 Sep
A drizzly and cloudy day, extensive hill fog likely with fresh westerly winds.
Sun 20 Sep
Dull initially but cloud breaking away from windward hills to leave a reasonable day, particularly for eastern areas. Lighter north-westerly 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.