Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High confidence in the unsettled conditions over the next few days, but lower confidence in the extent and timing of showers and how high the winds will get on Wednesday.
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.
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
Mostly dry with strong winds slowly easing.
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
40% | 20% | 30% | 30% | 20% | 70% |
Wind direction and speed (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
W
37
|
W
31
|
W
26
|
W
23
|
SW
24
|
SW
21
|
| 600m |
W
25
|
W
23
|
W
19
|
W
17
|
SW
15
|
S
15
|
| 300m |
W
17
|
W
16
|
W
14
|
W
12
|
SW
9
|
S
9
|
| Valley |
W
18
|
W
17
|
W
15
|
W
12
|
SW
9
|
S
9
|
Wind gust (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 45 | 39 | 33 | 29 | 29 | 26 |
| 600m | 32 | 29 | 26 | 23 | 20 | 20 |
| 300m | 30 | 28 | 24 | 21 | 18 | 17 |
| Valley | 30 | 28 | 24 | 21 | 18 | 17 |
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
6°
|
6°
|
6°
|
7°
|
7°
|
6°
|
| 600m |
8°
|
8°
|
9°
|
10°
|
9°
|
9°
|
| 300m |
10°
|
11°
|
12°
|
13°
|
12°
|
11°
|
| Valley |
12°
|
13°
|
14°
|
14°
|
13°
|
12°
|
| Freezing Level |
1,800m
|
1,700m
|
1,600m
|
1,700m
|
1,900m
|
2,100m
|
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-1°
|
0°
|
1°
|
2°
|
2°
|
2°
|
| 600m |
3°
|
4°
|
6°
|
6°
|
6°
|
5°
|
| 300m |
7°
|
8°
|
10°
|
10°
|
10°
|
9°
|
| Valley |
9°
|
10°
|
11°
|
12°
|
12°
|
10°
|
Additional weather information
Meteorologist's view
There is a risk of a few showers, so waterproofs may be needed. However, conditions will generally become dry during the afternoon, with some sunny spells developing. Strong UV levels are possible, so appropriate sun protection is recommended.
Weather
Cloudy start with occasional light rain and initially windy conditions, with a risk of gales over the summits. Bright spells are expected to develop through the morning, and winds should ease for a time during the day. Most areas will remain dry, though an isolated shower is still possible. Cloud will thicken later, with a band of rain moving in during the evening.
Chance of cloud-free hill tops
40% rising to 80% through the morning, then dropping to 20% late evening.
Low cloud and visibility
Cloud down to 400-500metres at first, lifting through the morning but deterioating again late evening. Visibility generally good or very good, but poor in any rain or showers and very poor in any low cloud
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
A persistent band of rain, low cloud and strong winds moving through in the early morning. The rain may turn heavy at times, but should mostly clear to the east by mid-morning, though the low cloud will linger for longer. However later on there will be further outbreaks of rain and showers through the day. Strong winds throughout.
Chance of cloud-free hill tops
20% becoming 70%
Maximum wind speed expected
Southwesterly 20-25mph with gusts 40-45mph.
Temperature
- At 800m Plus 7 becoming plus 11.
- Valley Plus 11 becoming plus 17.
- Freezing level Above summits.
Low cloud and visibility
Extensive low cloud with bases down to 300-400m in the early hours, and possibly getting down to 150-200m at times. This slowly clearing to above the summits through the afternoon. Visibility poor or very poor in the rain and showers, becoming good later on.
Mountain weather information
Thu 18 Sep
Sunrise:
Sunset:
Unsettled with low cloud and showers for the morning, slowly clearing up in the morning. Strong winds easing through the day.
Fri 19 Sep
Sunrise:
Sunset:
Staying unsettled with further outbreaks of rain through the day. Light to moderate winds with temperatures around average.
Sat 20 Sep
Sunrise:
Sunset:
A mixture of sunshine and showers, with winds generally light to moderate.
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.