Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High for cloudy and settled conditions to start and turning colder by the start of next week, lower confidence in the 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.
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
Mainly cloudy and dry. Fresh northerly winds at first, becoming light from late morning.
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
10% | 20% | 10% | 10% | 10% | 10% |
Wind direction and speed (mph)
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
N
20
|
NE
12
|
E
8
|
N
5
|
NE
5
|
SE
4
|
| 600m |
N
13
|
NE
7
|
NE
6
|
N
5
|
E
4
|
SE
4
|
| 300m |
N
5
|
SE
2
|
N
3
|
N
3
|
SE
2
|
SE
3
|
| Valley |
N
6
|
SE
2
|
N
2
|
N
3
|
SE
2
|
S
3
|
Wind gust (mph)
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m | 24 | 14 | 11 | 7 | 6 | 6 |
| 600m | 16 | 9 | 8 | 6 | 5 | 6 |
| 300m | 10 | 4 | 5 | 4 | 3 | 4 |
| Valley | 10 | 4 | 4 | 4 | 3 | 5 |
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
7°
|
7°
|
6°
|
6°
|
5°
|
5°
|
| 600m |
9°
|
9°
|
8°
|
8°
|
7°
|
7°
|
| 300m |
10°
|
9°
|
10°
|
10°
|
9°
|
8°
|
| Valley |
11°
|
10°
|
11°
|
11°
|
10°
|
10°
|
| Freezing Level |
2,600m
|
2,400m
|
2,100m
|
2,000m
|
2,000m
|
2,000m
|
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
3°
|
4°
|
4°
|
5°
|
3°
|
3°
|
| 600m |
6°
|
7°
|
7°
|
7°
|
6°
|
6°
|
| 300m |
9°
|
9°
|
10°
|
10°
|
8°
|
8°
|
| Valley |
10°
|
10°
|
11°
|
11°
|
10°
|
9°
|
Additional weather information
Meteorologist's view
Temperatures will be around average for November, but with light winds during the afternoon it should feel reasonably pleasant below to the cloud layer, and in any brightness.
Weather
Extensive low cloud will affect much of the area through the morning, bringing a risk of some patchy drizzle at times, though it will be dry with some brightness in sheltered southern and western areas. Cloud should lift at lower levels by afternoon, though still affecting mid-level hills and peaks. The highest peaks (above 800-1000m) may see clear skies as they sit above the cloud. Similar conditions persisting into the evening, but with cloud bases lowering again.
Chance of cloud-free hill tops
20-40%. Medium confidence at best for clear skies above the inversion, with its height expected around 800-1000m.
Low cloud and visibility
The cloud layer will generally sit between 500 and 1000m, but could extend as low as 200m during the morning and evening. Very poor visibility in cloud, moderate to poor in any drizzle, otherwise good.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Cloudy with intermittent drizzle, perhaps persistent on some northern hills. Cloud bases generally in the region of 400-600m, though perhaps lifting to around 800m at times, especially in the south. Light winds at first, but fresh to strong south-westerlies developing through the day.
Chance of cloud-free hill tops
20-40%. The temperature inversion at around 800-1000m will give a chance of cloud-free hill tops on some of the highest peaks.
Maximum wind speed expected
Southwesterly 15-20mph with gusts 25-30mph, but gusts locally reaching as high at 40mph near temperature inversion on the highest summits.
Temperature
- At 800m Plus 4 Celsius.
- Valley Plus 9 Celsius.
- Freezing level Above summits.
Low cloud and visibility
Generally moderate to poor in outbreaks of drizzle, but occasionally good in any drier spells. Very poor within cloud at mid and higher elevations.
Mountain weather information
Sat 16 Nov
Sunrise:
Sunset:
Cloudy with occasional rain or drizzle, heavy at times. Fresh to strong west-southwesterly winds becoming northwesterly. Freezing level above summits.
Sun 17 Nov
Sunrise:
Sunset:
Cloudy and wet, becoming brighter with scattered showers through the day. Some showers heavy, with a risk of hail and thunder, falling as snow on the highest peaks. Strong to gale force winds and increasing wind chill. Freezing level just above summits.
Mon 18 Nov
Sunrise:
Sunset:
Cold with strong northwesterly winds and blustery showers, some heavy with a risk of hail and thunder, falling as snow above 500m. Freezing level down to 500m.
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.