Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
Low confidence in eastward extent of cloud on Sunday, but high for progression into warmer and settled conditions from Monday.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
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.
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.
Mountain weather forecast
Sunny spells, patchy cloud across western parts.
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
<05% | 10% | 20% | 20% | 10% | 10% |
Wind direction and speed (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
SW
28
|
SW
26
|
SW
27
|
SW
27
|
SW
28
|
SW
26
|
| 600m |
S
21
|
S
21
|
S
22
|
SW
23
|
SW
21
|
SW
20
|
| 300m |
S
14
|
S
15
|
S
15
|
SW
16
|
SW
14
|
SW
12
|
| Valley |
S
14
|
S
15
|
S
15
|
SW
16
|
SW
14
|
S
12
|
Wind gust (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 33 | 32 | 34 | 34 | 35 | 32 |
| 600m | 26 | 27 | 29 | 30 | 28 | 26 |
| 300m | 23 | 24 | 25 | 26 | 24 | 21 |
| Valley | 23 | 24 | 25 | 25 | 23 | 21 |
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
5°
|
6°
|
7°
|
7°
|
7°
|
6°
|
| 600m |
6°
|
7°
|
8°
|
9°
|
9°
|
8°
|
| 300m |
9°
|
10°
|
10°
|
11°
|
11°
|
10°
|
| Valley |
10°
|
11°
|
12°
|
13°
|
12°
|
11°
|
| Freezing Level |
2,300m
|
2,300m
|
2,300m
|
2,200m
|
1,900m
|
2,300m
|
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-1°
|
0°
|
1°
|
2°
|
2°
|
1°
|
| 600m |
2°
|
3°
|
4°
|
5°
|
5°
|
4°
|
| 300m |
5°
|
6°
|
8°
|
8°
|
8°
|
7°
|
| Valley |
7°
|
8°
|
9°
|
10°
|
10°
|
8°
|
Additional weather information
Meteorologist's view
It will be breezy, especially across the higher tops, with a risk of severe wind chill at times. Despite this, when the sun breaks through, UV levels will be high, so sun cream will likely be needed.
Weather
Mist and fog patches in the valleys, as well as low cloud over western-facing slopes, should mostly clear through the early morning although this most likely short-lived for western areas, where thicker cloud is likely to move in through the day. This bringing the chance of light rain at times. Elsewhere, expect variable amounts of cloud with plenty of sunny spells, especially toward the far east. Cloud perhaps becoming more extensive into the evening.
Chance of cloud-free hill tops
40% to the northwest of the park, 70% elsewhere, with 90% to the east.
Low cloud and visibility
Areas of broken to overcast cloud cover are expected to affect western and northwestern ranges at times with cloud bases around 300-400m. Visibility generally good or very good outside of mist, fog or low cloud.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Some mist and fog may form in the valleys early in the morning, with cloud possibly lingering over the western ranges. However, this should quickly lift and break up through the morning, leading to a sunny day.
Chance of cloud-free hill tops
30% in the west at first, otherwise 90%.
Maximum wind speed expected
Southerly 5-7mph, with gusts 13-16mph.
Temperature
- At 800m Plus 5 Celsius rising to Plus 11 Celsius.
- Valley Plus 3 Celsius rising to Plus 17 Celsius.
- Freezing level Above all summits.
Low cloud and visibility
Poor or very poor in early morning mist, fog or low cloud, otherwise good or very good. Cloud around 200-300 metres at first to the west of the park, soon lifting above all summits.
Mountain weather information
Tue 29 Apr
Sunrise:
Sunset:
Fine and settled conditions, with very little in the way of cloud. Feeling warm as temperatures trend upwards. Light southeasterly breeze. Freezing level remaining above summits.
Wed 30 Apr
Sunrise:
Sunset:
Sunny and dry conditions persisting with warm or very warm temperatures. Light south or southwesterly winds. Freezing level above summits.
Thu 1 May
Sunrise:
Sunset:
Sunny and dry conditions likely continuing to persist, with warm or very warm temperatures. Light or moderate southwesterly 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.