Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High for rain to ease during Saturday then a spell of cold and bright weather with lighter winds from Sunday.
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.
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
Occasional rain with extensive low cloud. Gales slowly easing.
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
80% | 70% | 70% | 60% | 60% | 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 |
E
42
|
E
32
|
E
28
|
E
27
|
E
26
|
E
29
|
| 600m |
E
29
|
E
22
|
E
19
|
E
18
|
E
18
|
E
20
|
| 300m |
E
26
|
E
20
|
E
17
|
E
15
|
E
15
|
E
16
|
| Valley |
E
26
|
E
20
|
E
17
|
E
15
|
E
14
|
E
16
|
Wind gust (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 51 | 42 | 37 | 35 | 34 | 37 |
| 600m | 42 | 35 | 30 | 28 | 27 | 30 |
| 300m | 43 | 34 | 28 | 26 | 25 | 28 |
| Valley | 43 | 34 | 28 | 25 | 25 | 27 |
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
2°
|
3°
|
4°
|
5°
|
4°
|
4°
|
| 600m |
4°
|
5°
|
6°
|
7°
|
6°
|
6°
|
| 300m |
6°
|
7°
|
8°
|
8°
|
8°
|
7°
|
| Valley |
8°
|
8°
|
9°
|
10°
|
9°
|
8°
|
| Freezing Level |
2,200m
|
2,200m
|
2,100m
|
2,000m
|
2,000m
|
2,000m
|
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-6°
|
-4°
|
-2°
|
-1°
|
-2°
|
-3°
|
| 600m |
-2°
|
0°
|
2°
|
2°
|
2°
|
1°
|
| 300m |
1°
|
3°
|
4°
|
5°
|
4°
|
4°
|
| Valley |
3°
|
4°
|
6°
|
6°
|
6°
|
5°
|
Additional weather information
Meteorologist's view
Gales on high slopes this morning with strong gusts on lee slopes, then winds decreasing this afternoon. Note that streams and rivers and some approach roads may still be flooded following the heavy rain.
Weather
Outbreaks of rain will continue for much of today, locally heavy at first but gradually becoming lighter and more drizzly through the afternoon. Extensive hill fog. Significant windchill over ridges and summits.
Chance of cloud-free hill tops
Nil.
Low cloud and visibility
Poor or very poor visibility with extensive cloud down to low slopes for much of today.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Patchy rain clearing overnight. A cloudy start but soon brightening up with plenty of sunshine for the afternoon. Then dry and largely clear through the evening.
Chance of cloud-free hill tops
10% overnight becoming 90% or above during the morning.
Maximum wind speed expected
East 25 to 30 mph gusts 40-45 mph.
Temperature
- At 800m Plus 2 or 3C.
- Valley Plus 7 or 8C.
- Freezing level Above summits, falling to 900m during afternoon.
Low cloud and visibility
Cloud down to low slopes overnight. This clearing during the morning then excellent visibility expected for rest of the day with any cloud above summits.
Mountain weather information
Mon 17 Nov
Sunrise:
Sunset:
Dry with plenty of sunshine. Feeling very cold with fresh northeast winds on the tops easing. Freezing level 600m, falling to lower slopes in evening. Significant windchill.
Tue 18 Nov
Sunrise:
Sunset:
Showers or longer outbreaks of rain, falling as sleet or snow above 500-600m. Remaining cold with light northerly winds. Freezing level 600m but down to lower slopes overnight. Significant windchill.
Wed 19 Nov
Sunrise:
Sunset:
Remaining cold and with bright spells and some wintry showers. Freezing level 600m but down to lower slopes overnight. Significant windchill.
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.