Mountain weather
Eryri / Snowdonia
Confidence
Generally high for the overall evolution, but medium for the detail regards to rainfall and cloud on Sunday.
-
Sun 13 SepSunrise:Sunset:
-
Mon 14 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
Heavy Persistent Rain
Strong Sunlight
Mountain weather forecast
Outbreaks of rain easing during the afternoon.
|
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 |
<5%
|
<5%
|
<5%
|
<5%
|
<5%
|
<5%
|
Wind direction and speed
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | W 12mph knots
W
12mph |
W 8mph knots
W
8mph |
W 10mph knots
W
10mph |
SW 11mph knots
SW
11mph |
SW 12mph knots
SW
12mph |
S 14mph knots
S
14mph |
|
600m
|
600m | SW 8mph knots
SW
8mph |
SW 6mph knots
SW
6mph |
SW 8mph knots
SW
8mph |
SW 9mph knots
SW
9mph |
S 10mph knots
S
10mph |
S 12mph knots
S
12mph |
|
300m
|
300m | S 2mph knots
S
2mph |
NW 2mph knots
NW
2mph |
W 6mph knots
W
6mph |
W 6mph knots
W
6mph |
S 6mph knots
S
6mph |
S 7mph knots
S
7mph |
|
Valley
|
Valley | S 2mph knots
S
2mph |
NW 2mph knots
NW
2mph |
W 6mph knots
W
6mph |
W 6mph knots
W
6mph |
S 5mph knots
S
5mph |
S 6mph knots
S
6mph |
Wind gust
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | 14mph | 11mph | 14mph | 15mph | 15mph | 17mph |
|
600m
|
600m | 10mph | 9mph | 11mph | 12mph | 13mph | 15mph |
|
300m
|
300m | 6mph | 4mph | 9mph | 10mph | 10mph | 14mph |
|
Valley
|
Valley | 6mph | 4mph | 9mph | 10mph | 9mph | 13mph |
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | 11 degrees Celsius 11°C | 11 degrees Celsius 11°C | 12 degrees Celsius 12°C | 12 degrees Celsius 12°C | 11 degrees Celsius 11°C | 11 degrees Celsius 11°C |
|
600m
|
600m | 13 degrees Celsius 13°C | 13 degrees Celsius 13°C | 14 degrees Celsius 14°C | 14 degrees Celsius 14°C | 13 degrees Celsius 13°C | 13 degrees Celsius 13°C |
|
300m
|
300m | 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 | 15 degrees Celsius 15°C |
|
Valley
|
Valley | 16 degrees Celsius 16°C | 17 degrees Celsius 17°C | 18 degrees Celsius 18°C | 18 degrees Celsius 18°C | 17 degrees Celsius 17°C | 16 degrees Celsius 16°C |
| Freezing Level | Freezing Level |
2700m
|
2700m
|
3000m
|
3100m
|
3100m
|
3700m
|
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | 9 degrees Celsius 9°C | 10 degrees Celsius 10°C | 10 degrees Celsius 10°C | 10 degrees Celsius 10°C | 9 degrees Celsius 9°C | 9 degrees Celsius 9°C |
|
600m
|
600m | 12 degrees Celsius 12°C | 12 degrees Celsius 12°C | 13 degrees Celsius 13°C | 13 degrees Celsius 13°C | 12 degrees Celsius 12°C | 11 degrees Celsius 11°C |
|
300m
|
300m | 15 degrees Celsius 15°C | 16 degrees Celsius 16°C | 17 degrees Celsius 17°C | 16 degrees Celsius 16°C | 15 degrees Celsius 15°C | 14 degrees Celsius 14°C |
|
Valley
|
Valley | 16 degrees Celsius 16°C | 17 degrees Celsius 17°C | 18 degrees Celsius 18°C | 18 degrees Celsius 18°C | 17 degrees Celsius 17°C | 15 degrees Celsius 15°C |
| Freezing Level | Freezing Level |
2700m
|
2700m
|
3000m
|
3100m
|
3100m
|
3700m
|
Additional weather information
Meteorologist's view
Low cloud and poor visibilities make navigation challenging, combined with wet surfaces and rain, suitable clothing is a necessity.
Weather
A wet start with any residual outbreaks of heavy rain easing to become patchier and lighter through the morning and into the afternoon but remaining largely cloudy through the day. Perhaps with some brighter spells developing later in the day. Winds also easing.
Chance of cloud-free hill tops
10% or less at first becoming 50% into the afternoon.
Low cloud and visibility
Extensive low cloud around 500-600 m but cloud bases lowering towards 400 m in the heaviest rain. Generally poor to very poor visibility in rain and low cloud, but good outside of low cloud.
Ground conditions
No recent ground conditions report available.
Mountain weather information
Weather
Often cloudy with showery outbreaks of rain affecting the park throughout the day. Skies breaking a little with some bright or sunny spells developing.
Chance of cloud-free hill tops
Little chance at first, rising to 40% into the afternoon
Maximum wind speed expected
Southwesterly 15-20mph, gusting 25 mph..
Temperature
- At 800m Plus 14 Celsius rising to plus 16 Celsius
- Valley Plus 19 Celsius rising to plus 23 Celsius
- Freezing level Above summits
Low cloud and visibility
Extensive low bases around 300-400 meters during the morning, however this lifting to 500-600 meters. Generally poor to very poor visibility in rain and low cloud, but good outside of low cloud.
Ground conditions
No recent ground conditions report available.
Mountain weather information
Tue 15 Sep
Rain clearing to leave sunny spells. Feeling fresher. Fresh northwesterly.
Wed 16 Sep
Largely dry with sunny intervals. Moderate to fresh westerly.
Thu 17 Sep
Unsettled with a fresh northwesterly leading to sunny spells and showers, these locally heavy.
Mountain weather information
Tue 15 Sep
Rain clearing to leave sunny spells. Feeling fresher. Fresh northwesterly.
Wed 16 Sep
Largely dry with sunny intervals. Moderate to fresh westerly.
Thu 17 Sep
Unsettled with a fresh northwesterly leading to sunny spells and showers, these locally heavy.
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.