Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High confidence in the generally settled conditions this weekend. Low confidence in the timing and extent of showers from Sunday onwards.
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
Fine and bright with long sunny intervals.
| Time | 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
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
E
8
|
SE
9
|
SE
10
|
SW
8
|
N
10
|
E
12
|
| 600m |
SE
7
|
NE
8
|
SE
8
|
W
8
|
N
8
|
E
7
|
| 300m |
SE
5
|
NE
6
|
SE
6
|
W
7
|
N
6
|
SE
3
|
| Valley |
SE
5
|
NE
6
|
SE
6
|
NW
7
|
N
6
|
SE
3
|
Wind gust (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 10 | 11 | 14 | 12 | 14 | 15 |
| 600m | 9 | 11 | 12 | 12 | 11 | 9 |
| 300m | 8 | 8 | 11 | 11 | 9 | 6 |
| Valley | 8 | 8 | 10 | 11 | 10 | 5 |
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
5°
|
6°
|
8°
|
10°
|
9°
|
9°
|
| 600m |
7°
|
8°
|
11°
|
11°
|
11°
|
10°
|
| 300m |
8°
|
11°
|
14°
|
14°
|
13°
|
10°
|
| Valley |
9°
|
12°
|
15°
|
15°
|
14°
|
10°
|
| Freezing Level |
1,400m
|
1,300m
|
1,500m
|
1,700m
|
1,800m
|
1,700m
|
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
2°
|
3°
|
6°
|
8°
|
7°
|
6°
|
| 600m |
5°
|
6°
|
9°
|
10°
|
9°
|
9°
|
| 300m |
7°
|
10°
|
13°
|
13°
|
12°
|
9°
|
| Valley |
8°
|
11°
|
14°
|
14°
|
13°
|
10°
|
Additional weather information
Meteorologist's view
Generally good conditions for hill-walking. High UV levels in the sunshine, with appropriate sun protection advised.
Weather
A chilly start under clear skies. Slight chance that some low cloud may affect eastern slopes initially, otherwise a fine and sunny day with some fair weather cloud bubbling up during the afternoon. Feeling warmer than previous days with gentle winds.
Chance of cloud-free hill tops
60% in the east of the park around dawn otherwise above 90%.
Low cloud and visibility
A low risk of some low cloud with bases around 400m on eastern hills at first, and poor visibility in association with this. Otherwise cloud should be above summit heights and visibility is expected to be very good to excellent.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Fine and dry with little in the way of cloud and plenty of sunshine. Chilly to start, particularly in sheltered valleys. High UV levels are expected.
Chance of cloud-free hill tops
Above 90%
Maximum wind speed expected
South to southeast 10-15mph gusting 20-25mph, turning northwest late on.
Temperature
- At 800m Plus 7 Celsius rising to Plus 15 Celsius
- Valley Plus 4 Celsius rising to Plus 20 Celsius.
- Freezing level Well above summits.
Low cloud and visibility
Few to scattered amounts of cloud developing during the day, remaining above tops throughout.
Mountain weather information
Sun 11 May
Sunrise:
Sunset:
Fine and dry day, with long sunny intervals through the morning. Cloud thickening during the afternoon to give spells of hazy sunshine. Chance of some outbreaks of showery rain overnight. Moderate to fresh easterly winds, turning northerly later. High UV levels in the sunshine. Freezing level staying above tops.
Mon 12 May
Sunrise:
Sunset:
Rather cloudy with scattered showers, which may turn heavy with a risk of lightning. Some brighter sunny spells likely, posing a risk of high UV. Cooler with fresh easterly winds. Low confidence in details.
Tue 13 May
Sunrise:
Sunset:
Variable cloud with a chance of further showers, perhaps locally heavy and thundery. Skies likely clearing later with freshening easterly winds. Freezing level above tops. Low confidence in details.
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.