Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High confidence in generally unsettled weather over the weekend, lower confidence in shower and cloud details.
This evening forecast
Showers through the evening turning into more persistent rain by midnight.
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.
Severe Chill Effect
Wind significantly lowers the ‘feels-like’ temperature relative to the actual temperature, with even moderate winds significantly adding to the chilling effect. Strong winds can result in a severe and debilitating wind chill many degrees below the actual temperature. This effect will be enhanced in rain or wet snow. Without protection, prolonged exposure could result in frost nip or frostbite on exposed parts of the body and/or hypothermia.
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.
Thunderstorms
Lightning is a significant mountain hazard which can result in serious injury or death. Mountain terrain often leaves one highly exposed to lightning strikes. Hail may give unpleasant conditions with torrential rain and localised flash flooding also possible, mainly in Summer months.
Heavy Persistent Rain
Heavy and persistent rain can lead to drenched clothing and footwear with waterproofs often becoming soaked through, especially if accompanied by strong winds. This can lead to significant loss of body heat and an increased likelihood of hypothermia. Terrain may turn increasingly boggy underfoot while streams can flood and become impassable. There may also be a risk of flooding in valleys or glens. If there is snow cover, a heightened avalanche hazard is possible and avalanche reports should be consulted where available.
Mountain weather forecast
Overnight rain turning to frequent showers during the day.
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
|
|
Chance of precipitation (at 800m) |
80% | 80% | 60% | 60% | 60% | 40% | 30% | 10% |
Wind direction and speed (mph)
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
SW
20
|
SW
18
|
SW
18
|
W
18
|
W
19
|
W
23
|
NW
26
|
NW
27
|
| 600m |
SW
14
|
SW
14
|
SW
13
|
W
14
|
W
15
|
W
18
|
NW
19
|
NW
16
|
| 300m |
SW
8
|
W
10
|
SW
9
|
W
10
|
W
12
|
W
14
|
NW
14
|
NW
10
|
| Valley |
SW
8
|
W
10
|
SW
9
|
W
10
|
W
12
|
W
14
|
NW
15
|
NW
11
|
Wind gust (mph)
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m | 24 | 22 | 22 | 23 | 26 | 31 | 33 | 34 |
| 600m | 18 | 18 | 17 | 19 | 21 | 26 | 26 | 22 |
| 300m | 16 | 17 | 14 | 16 | 20 | 23 | 24 | 19 |
| Valley | 16 | 17 | 15 | 17 | 20 | 23 | 25 | 20 |
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
5°
|
4°
|
4°
|
4°
|
5°
|
5°
|
5°
|
4°
|
| 600m |
7°
|
6°
|
6°
|
7°
|
7°
|
8°
|
7°
|
6°
|
| 300m |
9°
|
8°
|
8°
|
9°
|
10°
|
10°
|
9°
|
8°
|
| Valley |
10°
|
10°
|
10°
|
10°
|
11°
|
12°
|
11°
|
10°
|
| Freezing Level |
1,500m
|
1,600m
|
1,500m
|
1,600m
|
1,500m
|
1,600m
|
1,600m
|
1,400m
|
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
0°
|
0°
|
-1°
|
0°
|
0°
|
0°
|
-1°
|
-3°
|
| 600m |
3°
|
3°
|
2°
|
3°
|
4°
|
4°
|
2°
|
2°
|
| 300m |
7°
|
6°
|
6°
|
6°
|
7°
|
8°
|
6°
|
6°
|
| Valley |
8°
|
7°
|
8°
|
8°
|
9°
|
9°
|
8°
|
7°
|
Additional weather information
Meteorologist's view
Walkways and paths likely to be very wet and slippery through much of the day. Blustery conditions likely in association with showers, care to be taken when walking over exposed ridges and summits. Despite the unsettled weather, sunny spells through the afternoon, combined with high UV levels, mean sun protection is also advised.
Weather
Widespread rain across the region through the early hours, heaviest on western-facing slopes. Persistent rain and low cloud breaking up into showers and occasional sunny spells through the morning and afternoon, showers likely heavy at times with a risk of thunderstorms. Showers dying off into the evening, with some late clear skies developing.
Chance of cloud-free hill tops
20% first thing, mainly western slopes. Improving to 80% through the morning.
Low cloud and visibility
Overnight seeing widespread low cloud down to 500-600m, mostly across western hills. Low cloud lifting and breaking through the morning, clearing summits into the afternoon. Cloud frequently lowering to around 800m through the afternoon in heavier showers, shrouding some summits. Visibility very poor around dawn in rain and low cloud, gradually improving to good through the morning as conditions improve, however falling frequently to poor or very poor once again in showers.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Clear skies overnight will lead to a bright and sunny start. Cloud bubbling up through the morning, but still plenty of sunny spells through the day. Isolated showers possible, most likely through the afternoon and early evening.
Chance of cloud-free hill tops
90%
Maximum wind speed expected
Westerly 20-25mph, gusting 35-40mph in association with showers.
Temperature
- At 800m Plus 3 deg Celsius, rising to 7 deg Celsius.
- Valley Plus 9 deg Celsius, rising to 13 deg Celsius.
- Freezing level Above summits.
Low cloud and visibility
Scraps of cloud overnight may temporarily shroud some western summits, but cloud generally expected to be above the summits throughout, only lowering infrequently in any heavier showers through the afternoon or evening. Visibility generally very good to excellent, falling to poor or very poor in showers
Mountain weather information
Mon 9 Jun
Sunrise:
Sunset:
Variable cloud and sunny spells, perhaps the odd shower. Fresh to strong southwesterly winds.
Tue 10 Jun
Sunrise:
Sunset:
Cloudy, likely seeing some light rain at times, mainly across western-facing slopes. Fresh to strong southwesterly winds.
Wed 11 Jun
Sunrise:
Sunset:
Variable cloud and sunny spells. Fresh to strong southerly winds.
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.