Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High confidence for a mostly fine dry and settled spell of weather next few days. Lower confidence for shower details during the week ahead.
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
Dry, sunny and warm.
| 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 |
NE
14
|
NE
17
|
E
14
|
NE
9
|
NE
11
|
E
11
|
| 600m |
E
8
|
NE
10
|
E
11
|
NE
7
|
NE
5
|
E
8
|
| 300m |
E
3
|
N
5
|
NE
8
|
NE
8
|
N
5
|
E
6
|
| Valley |
SE
2
|
N
4
|
NE
8
|
N
7
|
NW
4
|
E
5
|
Wind gust (mph)
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m | 17 | 21 | 19 | 14 | 15 | 15 |
| 600m | 11 | 14 | 16 | 11 | 10 | 13 |
| 300m | 4 | 8 | 13 | 12 | 8 | 10 |
| Valley | 4 | 7 | 13 | 11 | 6 | 9 |
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
12°
|
11°
|
13°
|
14°
|
14°
|
12°
|
| 600m |
13°
|
14°
|
15°
|
16°
|
16°
|
14°
|
| 300m |
14°
|
16°
|
18°
|
18°
|
18°
|
15°
|
| Valley |
14°
|
17°
|
19°
|
19°
|
18°
|
16°
|
| Freezing Level |
2,300m
|
2,100m
|
1,800m
|
2,000m
|
2,100m
|
2,100m
|
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
9°
|
8°
|
10°
|
12°
|
12°
|
10°
|
| 600m |
12°
|
12°
|
13°
|
15°
|
15°
|
12°
|
| 300m |
14°
|
16°
|
16°
|
17°
|
17°
|
14°
|
| Valley |
14°
|
17°
|
17°
|
17°
|
17°
|
15°
|
Additional weather information
Meteorologist's view
Cloud may make navigation tricky if near summits around sunrise. Sun protection advised through the middle and latter part of the day, as UV levels will be high.
Weather
Patchy low cloud, mist and fog early morning soon clearing to leave a fine and dry day, with long spells of warm sunshine. Staying fine, dry and sunny/clear into the evening.
Chance of cloud-free hill tops
95% throughout
Low cloud and visibility
Cloud bases down to 700-800m early morning, quickly lifting above the summits soon after sunrise. Visibility will be generally poor in early cloud at elevation, otherwise, very good throughout, with good views of distant hills.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Dry with clear skies overnight, perhaps some shallow mist and fog patches in the valleys, although these should soon clear after sunrise. Fine and dry, with long spells of sunshine throughout the day. Staying fine and dry, with prolonged sunshine/clear skies during the evening.
Chance of cloud-free hill tops
95% throughout.
Maximum wind speed expected
East to northeast 5-10mph throughout.
Temperature
- At 800m Plus 09 Celsius, becoming Plus 13 Celsius.
- Valley Plus 03 Celsius, becoming Plus 19 Celsius.
- Freezing level Above the summits.
Low cloud and visibility
Cloud will remain above the summits. Visibility will be poor in early mist and valley fog early morning, until just after sunrise. Otherwise, very good with distant hills clearly visible.
Mountain weather information
Tue 21 May
Sunrise:
Sunset:
A fine and bright start for many. However, the cloud will be bubbling up to bring some showers during the afternoon, these are likely to be slow moving, heavy and possibly thundery. Warm in the sunshine. Light and variable winds. Freezing level above the summits.
Wed 22 May
Sunrise:
Sunset:
Early mist and fog patches soon lifting and clearing to leave a largely dry and bright start, with sunny spells. However, a few scattered showers are likely to develop during the afternoon. Warm in the sunshine. Light west to northwest winds. Freezing level above the summits.
Thu 23 May
Sunrise:
Sunset:
Dry and bright at first. Otherwise, another day of sunny spells and scattered showers, possibly heavy at times. Warm in the sunshine. Light northwest winds. Freezing level above the summits.
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.