Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High confidence that high pressure will give a lot of fine weather next few days. Moderate confidence regarding low cloud and fog details. Moderate confidence that the weather will become more changeable over the weekend, but lower confidence at this stage regarding rainfall details.
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.
Gales
Gale force winds (gusts over 50mph) make walking difficult and strenuous with a potential to be blown over by gusts. There is often a marked increase in winds through cols or on exposed ridges and summits. Distances can take longer to cover and compass bearings become harder to follow accurately.
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.
Mountain weather forecast
A cloudy start with some fog and patchy drizzle. Much brighter later.
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
20% | 20% | 10% | <05% | 00% | 00% |
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
32
|
E
23
|
E
21
|
NE
22
|
NE
24
|
E
31
|
| 600m |
NE
16
|
E
14
|
NE
15
|
NE
16
|
NE
15
|
NE
14
|
| 300m |
NE
11
|
E
9
|
E
10
|
NE
11
|
NE
10
|
NE
7
|
| Valley |
NE
10
|
E
9
|
E
10
|
NE
10
|
NE
10
|
NE
6
|
Wind gust (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 38 | 29 | 27 | 28 | 30 | 40 |
| 600m | 22 | 19 | 21 | 22 | 20 | 22 |
| 300m | 22 | 18 | 17 | 19 | 18 | 18 |
| Valley | 21 | 17 | 17 | 18 | 17 | 17 |
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
2°
|
3°
|
4°
|
5°
|
6°
|
4°
|
| 600m |
4°
|
5°
|
7°
|
8°
|
8°
|
7°
|
| 300m |
7°
|
8°
|
10°
|
11°
|
10°
|
9°
|
| Valley |
9°
|
10°
|
11°
|
12°
|
12°
|
10°
|
| Freezing Level |
1,500m
|
1,400m
|
1,400m
|
1,500m
|
1,500m
|
1,400m
|
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-6°
|
-4°
|
-2°
|
0°
|
0°
|
-2°
|
| 600m |
0°
|
1°
|
3°
|
4°
|
5°
|
3°
|
| 300m |
4°
|
6°
|
7°
|
9°
|
8°
|
7°
|
| Valley |
6°
|
8°
|
9°
|
10°
|
10°
|
9°
|
Additional weather information
Meteorologist's view
Early fog patches are likely to give poor conditions for navigating. Given the time of year when the sun breaks through for the afternoon, it will become quite strong, so sun protection advised. There will be a cold wind on the hill tops, so warm clothing is advised.
Weather
Low cloud with a small chance of light rain or drizzle. Fog over the summits slowly clearing through the morning, with cloud lifting to give some sunny intervals during the afternoon. Becoming clear in the evening.
Chance of cloud-free hill tops
20% at first, rising to 70% or more by midday, then 100% under clear skies in the evening.
Low cloud and visibility
Cloud likely to obscure hills above about 700-800m at first. Cloud lifting above the hill tops during the morning, then skies clearing during the evening. Visibility poor in early fog and any drizzle, becoming good or very good from late morning, with distant hills visible later in the day.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Dry with mostly clear or sunny weather. A small chance of the odd mist patch at first, with a slight frost on the summits. Some high cloud possible during the evening.
Chance of cloud-free hill tops
80% or more throughout the day.
Maximum wind speed expected
East to northeasterly, 35 to 40mph, occasionally perhaps 45mph, with gusts 45 to 50mph, perhaps 55mph at times later.
Temperature
- At 800m Plus 2 Celsius rising to plus 12 Celsius.
- Valley plus 5 Celsius rising to plus 18 Celsius.
- Freezing level Near the summits at first in the morning, otherwise above throughout.
Low cloud and visibility
Isolated mist patches at first could give locally moderate visibility, otherwise clear skies with good or very good visibility.
Mountain weather information
Thu 30 Apr
Sunrise:
Sunset:
Dry with plenty of sunshine. Cloud increasing late afternoon into the evening with a chance of showers later. Brisk and gusty easterly winds easing slowly and turning southeasterly. Very good visibility until any showers arrive later. Freezing levels above the summits throughout.
Fri 1 May
Sunrise:
Sunset:
Mostly cloudy with a chance of showers at times. Winds lighter than recently. Visibility moderate in any showers. Freezing levels above the summits throughout.
Sat 2 May
Sunrise:
Sunset:
Remaining rather cloudy with some mostly light showers. Breezy on the summits. Freezing levels above the summits throughout.
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.