Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High confidence for a settled and generally fine period of weather over the coming days. Lower confidence with regards to extent of any early morning mist, fog and low cloud detail on each day. Low for extent of cloud and potential showers by the end of the week.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
Strong Sunlight
Harmful UV levels from sunlight increase with altitude giving a greater risk of sunburn and eye damage, even on some overcast days. On breezy days, the cooling effect of wind on exposed skin may disguise any feeling of sunburn until it is too late. If there is snow cover, glare increases the effect of UV rays especially on the eyes. It is advisable to wear sun block, protective clothing such as a long-sleeved top and hat and have good quality eye protection.
Poor Visibility
Poor visibility presents challenging route finding conditions. Visibility could be significantly less than 50 metres in all directions with few or no visual references, especially on featureless moors or plateaux. Distances become hard to judge and cliff or cornice edges can be difficult to recognise. These conditions require good navigational skills. There is a risk of white-out conditions when mist or fog is combined with extensive snow cover.
Mountain weather forecast
Any early low cloud, mist or fog patches clearing to give another fine bright day.
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
<05% | <05% | <05% | <05% | <05% | <05% |
Wind direction and speed (mph)
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
E
16
|
E
14
|
E
16
|
E
17
|
E
18
|
E
20
|
| 600m |
SE
8
|
E
11
|
E
11
|
E
11
|
E
14
|
E
17
|
| 300m |
SE
6
|
E
7
|
E
7
|
E
8
|
E
9
|
E
12
|
| Valley |
SE
6
|
E
7
|
E
7
|
E
8
|
E
9
|
SE
12
|
Wind gust (mph)
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m | 20 | 19 | 21 | 22 | 25 | 26 |
| 600m | 12 | 15 | 15 | 17 | 24 | 25 |
| 300m | 11 | 13 | 12 | 15 | 19 | 24 |
| Valley | 11 | 13 | 12 | 15 | 17 | 22 |
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
10°
|
10°
|
10°
|
12°
|
12°
|
11°
|
| 600m |
12°
|
12°
|
13°
|
14°
|
14°
|
14°
|
| 300m |
13°
|
13°
|
16°
|
17°
|
15°
|
14°
|
| Valley |
13°
|
14°
|
17°
|
18°
|
16°
|
15°
|
| Freezing Level |
3,000m
|
2,400m
|
2,800m
|
2,800m
|
2,600m
|
2,400m
|
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
7°
|
6°
|
8°
|
9°
|
8°
|
8°
|
| 600m |
10°
|
9°
|
11°
|
12°
|
11°
|
10°
|
| 300m |
11°
|
12°
|
15°
|
16°
|
14°
|
12°
|
| Valley |
12°
|
13°
|
16°
|
17°
|
15°
|
12°
|
Additional weather information
Meteorologist's view
Moderate to strong UV is still expected on the tops with plenty of sunshine forecast. Don't forget to take appropriate sun protection, especially if starting off in the valley fog or cloud.
Weather
Isolated patches of mist and fog in low lying valleys, mainly in the west with low cloud spreading in from the east. Hill tops likely to be above the cloud with good visibilities above the inversion. Mist, fog and low cloud will soon lift and disperse to give a fine day with plenty of sunshine.
Chance of cloud-free hill tops
80% becoming greater than 95%.
Low cloud and visibility
Some low cloud and poor visibility between around 300-400m possible on eastern facing slopes in the east of the range, with valley fog and some patchy poor visibility a risk more widely. Low cloud steadily lifting and breaking through the morning however to leave clear summits into the day for all parts, with visibility becoming good or very good for distant views of hills and peaks.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Very similar conditions to Wednesday expected with overnight cloud in the east brining hill fog and the odd spot of drizzle to eastern slopes. Cloud lifting and clearing into the morning to leave a fine and bright afternoon. Fresh easterly winds persisting.
Chance of cloud-free hill tops
60 becoming 90% by the afternoon.
Maximum wind speed expected
Easterly 20mph gusting 30mph becoming 40-45mph by the evening.
Temperature
- At 800m Plus 10 Celsius, becoming Plus 13 Celsius.
- Valley Plus 6 Celsius, becoming Plus 20 Celsius.
- Freezing level Above the summits.
Low cloud and visibility
Some low cloud and poor visibility possible on eastern facing slopes in the east of the range into the early hours. Low cloud steadily lifting and breaking through the morning however to leave clear summits into the day for all parts, with visibility becoming good or very good for distant views of hills and peaks.
Mountain weather information
Fri 20 Sep
Sunrise:
Sunset:
Another cloudy start possible in the east with cloud burning away in the afternoon to bring brighter spells with a risk of showers. Strong easterly winds persisting.
Sat 21 Sep
Sunrise:
Sunset:
Any early low cloud once again breaking up to give bright or sunny spells, with the chance of showers, possibly heavy and thundery, by the afternoon. Gale force easterly winds.
Sun 22 Sep
Sunrise:
Sunset:
The threat of some low cloud and lingering showers overnight once again breaking up to give bright or sunny spells, with a band of rain edging north slowly. Moderate easterly winds persisting.
Updated at:
Summit specific forecast
Mountain summit forecast map
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Key
Mountain summits
Other points of interest
Cluster of multiple stations
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.