Mountain weather
Eryri / Snowdonia
Confidence
High confidence for a changeable theme. Lower for the clearance of low cloud and rain tomorrow morning and arrival tomorrow night.
-
Tue 29 SepSunrise:Sunset:
-
Wed 30 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
Gales
Heavy Persistent Rain
Mountain weather forecast
Damp and dull start. Brighter by the afternoon, with heavy rain arriving later. Windy.
|
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 |
80%
|
80%
|
50%
|
20%
|
20%
|
70%
|
Wind direction and speed
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | E 42mph knots
E
42mph |
SE 47mph knots
SE
47mph |
SE 45mph knots
SE
45mph |
SE 43mph knots
SE
43mph |
SE 45mph knots
SE
45mph |
SE 45mph knots
SE
45mph |
|
600m
|
600m | SE 23mph knots
SE
23mph |
SE 29mph knots
SE
29mph |
SE 31mph knots
SE
31mph |
SE 29mph knots
SE
29mph |
SE 31mph knots
SE
31mph |
SE 31mph knots
SE
31mph |
|
300m
|
300m | SE 15mph knots
SE
15mph |
SE 21mph knots
SE
21mph |
SE 23mph knots
SE
23mph |
SE 21mph knots
SE
21mph |
SE 20mph knots
SE
20mph |
SE 20mph knots
SE
20mph |
|
Valley
|
Valley | SE 14mph knots
SE
14mph |
SE 20mph knots
SE
20mph |
SE 23mph knots
SE
23mph |
SE 21mph knots
SE
21mph |
SE 20mph knots
SE
20mph |
SE 20mph knots
SE
20mph |
Wind gust
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | 47mph | 54mph | 54mph | 52mph | 54mph | 55mph |
|
600m
|
600m | 30mph | 36mph | 40mph | 38mph | 40mph | 40mph |
|
300m
|
300m | 29mph | 36mph | 39mph | 36mph | 37mph | 37mph |
|
Valley
|
Valley | 29mph | 36mph | 38mph | 36mph | 37mph | 37mph |
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | 8 degrees Celsius 8°C | 10 degrees Celsius 10°C | 12 degrees Celsius 12°C | 14 degrees Celsius 14°C | 15 degrees Celsius 15°C | 14 degrees Celsius 14°C |
|
600m
|
600m | 10 degrees Celsius 10°C | 11 degrees Celsius 11°C | 14 degrees Celsius 14°C | 17 degrees Celsius 17°C | 17 degrees Celsius 17°C | 16 degrees Celsius 16°C |
|
300m
|
300m | 12 degrees Celsius 12°C | 14 degrees Celsius 14°C | 16 degrees Celsius 16°C | 20 degrees Celsius 20°C | 19 degrees Celsius 19°C | 18 degrees Celsius 18°C |
|
Valley
|
Valley | 13 degrees Celsius 13°C | 15 degrees Celsius 15°C | 18 degrees Celsius 18°C | 21 degrees Celsius 21°C | 21 degrees Celsius 21°C | 20 degrees Celsius 20°C |
| Freezing Level | Freezing Level |
2200m
|
2900m
|
3100m
|
3200m
|
3200m
|
3200m
|
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | 2 degrees Celsius 2°C | 4 degrees Celsius 4°C | 6 degrees Celsius 6°C | 8 degrees Celsius 8°C | 8 degrees Celsius 8°C | 7 degrees Celsius 7°C |
|
600m
|
600m | 6 degrees Celsius 6°C | 7 degrees Celsius 7°C | 9 degrees Celsius 9°C | 11 degrees Celsius 11°C | 11 degrees Celsius 11°C | 10 degrees Celsius 10°C |
|
300m
|
300m | 9 degrees Celsius 9°C | 10 degrees Celsius 10°C | 12 degrees Celsius 12°C | 15 degrees Celsius 15°C | 15 degrees Celsius 15°C | 15 degrees Celsius 15°C |
|
Valley
|
Valley | 10 degrees Celsius 10°C | 12 degrees Celsius 12°C | 14 degrees Celsius 14°C | 17 degrees Celsius 17°C | 17 degrees Celsius 17°C | 16 degrees Celsius 16°C |
| Freezing Level | Freezing Level |
2200m
|
2900m
|
3100m
|
3200m
|
3200m
|
3200m
|
Additional weather information
Meteorologist's view
Good navigational skills required in low cloud and poor visibilities. Conditions improving later with moderate UV levels however strong to gale force winds will likely make moving across exposed terrain difficult with strong buffeting near summits.
Weather
Low cloud bringing a risk of hill fog, light rain and drizzle through the morning. This is expected to lift and break into the afternoon with a band of heavy and persistent rain, arriving from the west, overnight. Turning unsettled and windy with strong southeasterly winds developing and a chance of summit gales.
Chance of cloud-free hill tops
10% rising to over 60% by mid-afternoon.
Low cloud and visibility
Cloud bases initially 300-400m, possibly as low as 200m in places, rising to 500-600m by the afternoon, before gradually rising above summits. Poor or very poor visibilities in hill fog and drizzle, otherwise moderate visibilities in light rain. Good views of distant hills by the afternoon once the rain and cloud clears. Low cloud and hill fog, as well as a deterioration in visibilities can be expected overnight when another band of rain arrives.
Ground conditions
No recent ground conditions report available.
Mountain weather information
Weather
Very wet and windy overnight with a band of heavy rain clearing most of the park by dawn. Thereafter a breezy day with sunny spells and showers, some may be heavy at times.
Chance of cloud-free hill tops
20% overnight, becoming 80% by mid-morning.
Maximum wind speed expected
Southwesterly 15-20mph, gusting 25-30mph, gusts of 35-40mph possible in or around showers.
Temperature
- At 800m Plus 7 Celsius rising to plus 10 Celsius.
- Valley Plus 15 Celsius rising to plus 17 Celsius.
- Freezing level Above summits.
Low cloud and visibility
Low cloud down to 400-500 m first thing, otherwise rising mostly at or above summits by mid-morning. Poor visibility during the morning then very good, although may deteriorate temporarily in afternoon showers.
Ground conditions
No recent ground conditions report available.
Mountain weather information
Thu 1 Oct
Another rather breezy day ahead with bright or sunny spells as well as scattered showers.
Fri 2 Oct
Showery outbreaks of rain and stronger winds on Friday.
Sat 3 Oct
More settled on Saturday with high pressure. Still the risk of the odd shower but light and variable winds.
Mountain weather information
Thu 1 Oct
Another rather breezy day ahead with bright or sunny spells as well as scattered showers.
Fri 2 Oct
Showery outbreaks of rain and stronger winds on Friday.
Sat 3 Oct
More settled on Saturday with high pressure. Still the risk of the odd shower but light and variable 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.