Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
Moderate to high confidence to see a breakdown of the recent settled conditions and into more changeable weather. Lower confidence in northern extent of rain Wednesday morning and spatial extent of showers through the afternoon.
This evening forecast
Isolated heavy showers during the evening will gradually fizzle out overnight, with a reducing risk of thunder.
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.
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.
Mountain weather forecast
Drier and brighter conditions in the northwest, largely cloudy in southern regions with outbreaks of rain clearing south, shortly followed by some heavier showers, especially towards the east
| 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) |
00% | 30% | 40% | 10% | 20% | 30% | 10% | 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 |
N
5
|
N
6
|
N
9
|
N
11
|
N
13
|
N
15
|
N
15
|
N
12
|
| 600m |
NW
3
|
N
3
|
N
4
|
N
10
|
N
12
|
N
14
|
N
11
|
NE
5
|
| 300m |
W
2
|
W
2
|
W
2
|
NW
7
|
N
9
|
N
11
|
N
8
|
NE
2
|
| Valley |
W
2
|
W
2
|
SW
3
|
NW
7
|
N
10
|
N
11
|
N
8
|
SW
2
|
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 | 7 | 8 | 12 | 15 | 19 | 22 | 20 | 15 |
| 600m | 6 | 5 | 7 | 14 | 17 | 20 | 16 | 8 |
| 300m | 4 | 4 | 5 | 11 | 15 | 17 | 13 | 5 |
| Valley | 4 | 4 | 5 | 11 | 15 | 17 | 13 | 5 |
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
7°
|
6°
|
6°
|
8°
|
9°
|
10°
|
9°
|
8°
|
| 600m |
8°
|
7°
|
8°
|
10°
|
12°
|
12°
|
12°
|
10°
|
| 300m |
9°
|
9°
|
10°
|
13°
|
15°
|
15°
|
14°
|
12°
|
| Valley |
10°
|
10°
|
11°
|
14°
|
16°
|
16°
|
15°
|
12°
|
| Freezing Level |
1,700m
|
1,700m
|
1,700m
|
1,700m
|
1,800m
|
1,800m
|
1,800m
|
1,600m
|
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°
|
5°
|
6°
|
6°
|
6°
|
5°
|
| 600m |
8°
|
7°
|
7°
|
8°
|
10°
|
10°
|
9°
|
9°
|
| 300m |
9°
|
9°
|
9°
|
11°
|
13°
|
13°
|
12°
|
11°
|
| Valley |
10°
|
10°
|
10°
|
12°
|
14°
|
14°
|
14°
|
12°
|
Additional weather information
Meteorologist's view
UV levels are forecast to be High, so appropriate sun protection is recommended. Any showers may lead to rapid changes in weather conditions, so it's advisable to carry waterproof clothing-especially if you're heading into southern or eastern areas.
Weather
After a cloudy start to the day across much of the park, northern regions develop some brighter spells and stay dry. Meanwhile further towards the south, outbreaks of rain are expected through the early morning, gradually sinking south to leave sunny spells across the park. These brighter spells may then lead to a risk of showers developing across the park, most likely in the south and east, with a low risk of thunder in any heavy downpours.
Chance of cloud-free hill tops
40% in the south at first, 80% in the north, becoming 90% for all by the afternoon.
Low cloud and visibility
Cloudy conditions in the south with occasional cloud obscuring hills above 300-400m and light to moderate rain reducing the visibilities to moderate or poor. Further north, scattered cloud largely staying well above the summits with good to very good visibilities. Through the morning, cloud clears away from the south leaving sunny spells for all with showers developing through the afternoon, especially in the south and east. Cloud bases mostly staying above summits, but falling below, to around 600-700m in heavy showers. Visibilities very good to excellent, dropping to moderate or poor in heavy showers.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Southern and western parts will start the day with plenty of sunshine but cloud will quickly spread across the park during the morning, eventually lifting and breaking to see further sunny spells through the afternoon and into the evening.
Chance of cloud-free hill tops
70% in the morning, rising to 95% in the afternoon.
Maximum wind speed expected
Northerly wind 15mph increasing to 25mph with gusts over summits up to 35mph in the afternoon.
Temperature
- At 800m Plus 06 Celsius.
- Valley Plus 08 Celsius becoming Plus 18 Celsius.
- Freezing level Well above summits.
Low cloud and visibility
As cloud arrives from the northeast, bases are mostly expected to be just above summits, with perhaps some scattered cloud at around 800m, obscuring the tops of the highest hills. Throughout the afternoon, cloud bases will rise, and disperse with cloud expected to be well above summits. Visibilities very good to excellent with views of distant hills.
Mountain weather information
Fri 23 May
Sunrise:
Sunset:
A dry and bright day with sunshine turning increasingly hazy through the afternoon. Moderate to fresh northwesterly winds becoming southwesterly. Freezing level well above summits.
Sat 24 May
Sunrise:
Sunset:
Cloudy with rain arriving from the west and strengthening southwesterly winds. Freezing level well above summits.
Sun 25 May
Sunrise:
Sunset:
Sunny spells and showers with gale-force southwesterly winds. Freezing level well above 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.