Mountain weather
Eryri / Snowdonia
Confidence
Moderate for details of low cloud and rain/drizzle on Friday. High for a Saturday. Moderate for arrival time of rain and stronger winds on Sunday.
-
Fri 25 SepSunrise:Sunset:
-
Sat 26 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
Mountain weather forecast
Often damp with rain at times, turning drier later
|
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%
|
80%
|
60%
|
30%
|
20%
|
Wind direction and speed
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | NW 17mph knots
NW
17mph |
N 10mph knots
N
10mph |
NW 9mph knots
NW
9mph |
W 9mph knots
W
9mph |
SW 12mph knots
SW
12mph |
SW 19mph knots
SW
19mph |
|
600m
|
600m | N 7mph knots
N
7mph |
N 6mph knots
N
6mph |
NW 5mph knots
NW
5mph |
W 7mph knots
W
7mph |
SW 9mph knots
SW
9mph |
SW 12mph knots
SW
12mph |
|
300m
|
300m | N 4mph knots
N
4mph |
NW 4mph knots
NW
4mph |
NW 3mph knots
NW
3mph |
W 5mph knots
W
5mph |
S 5mph knots
S
5mph |
S 8mph knots
S
8mph |
|
Valley
|
Valley | W 5mph knots
W
5mph |
NW 5mph knots
NW
5mph |
W 3mph knots
W
3mph |
W 5mph knots
W
5mph |
S 4mph knots
S
4mph |
S 8mph knots
S
8mph |
Wind gust
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | 21mph | 12mph | 12mph | 12mph | 15mph | 25mph |
|
600m
|
600m | 11mph | 9mph | 8mph | 10mph | 13mph | 17mph |
|
300m
|
300m | 9mph | 7mph | 6mph | 7mph | 10mph | 16mph |
|
Valley
|
Valley | 9mph | 8mph | 6mph | 7mph | 9mph | 16mph |
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | 8 degrees Celsius 8°C | 8 degrees Celsius 8°C | 7 degrees Celsius 7°C | 7 degrees Celsius 7°C | 7 degrees Celsius 7°C | 7 degrees Celsius 7°C |
|
600m
|
600m | 10 degrees Celsius 10°C | 10 degrees Celsius 10°C | 9 degrees Celsius 9°C | 9 degrees Celsius 9°C | 9 degrees Celsius 9°C | 9 degrees Celsius 9°C |
|
300m
|
300m | 12 degrees Celsius 12°C | 11 degrees Celsius 11°C | 11 degrees Celsius 11°C | 12 degrees Celsius 12°C | 11 degrees Celsius 11°C | 11 degrees Celsius 11°C |
|
Valley
|
Valley | 13 degrees Celsius 13°C | 12 degrees Celsius 12°C | 13 degrees Celsius 13°C | 13 degrees Celsius 13°C | 12 degrees Celsius 12°C | 12 degrees Celsius 12°C |
| Freezing Level | Freezing Level |
3200m
|
2900m
|
2200m
|
1700m
|
1600m
|
1700m
|
|
Time
|
Time |
06:00
|
09:00
|
12:00
|
15:00
|
18:00
|
21:00
|
|---|---|---|---|---|---|---|---|
|
900m
|
900m | 4 degrees Celsius 4°C | 5 degrees Celsius 5°C | 4 degrees Celsius 4°C | 4 degrees Celsius 4°C | 4 degrees Celsius 4°C | 2 degrees Celsius 2°C |
|
600m
|
600m | 8 degrees Celsius 8°C | 8 degrees Celsius 8°C | 8 degrees Celsius 8°C | 8 degrees Celsius 8°C | 7 degrees Celsius 7°C | 6 degrees Celsius 6°C |
|
300m
|
300m | 11 degrees Celsius 11°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 | 13 degrees Celsius 13°C | 12 degrees Celsius 12°C | 12 degrees Celsius 12°C | 13 degrees Celsius 13°C | 12 degrees Celsius 12°C | 10 degrees Celsius 10°C |
| Freezing Level | Freezing Level |
3200m
|
2900m
|
2200m
|
1700m
|
1600m
|
1700m
|
Additional weather information
Meteorologist's view
The widespread cloud and rain will lead to tricky navigation, particularly across the higher ground through the morning and early afternoon. While not heavy, the persistent rain will lead to widely slippery conditions underfoot and full waterproofs a must too.
Weather
Widespread low cloud with light rain and drizzle, locally heavy first thing. The rain slowly clears to the southeast of the park through the afternoon, but remaining cloudy through the evening. Light winds.
Chance of cloud-free hill tops
10% becoming 70% by late afternoon.
Low cloud and visibility
Widespread low cloud above 400m initially, lifting and breaking from the northwest to scattered patches above 700m through the afternoon and mostly clearing above the summits by the evening. Very poor visibility in the cloud/fog and poor at lower levels in the rain. Improving later to good as rain eases.
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 south-westerly 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 above 800m for a time before lifting above the summits. Otherwise the higher cloud will be clear above the summits. Locally very poor visibility in early valley 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. Dry initially but with cloud and light rain by midday, turning persistent through the late afternoon and into the evening.
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. Dry initially but with cloud and light rain by midday, turning persistent through the late afternoon and into 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.