Mountain weather
Snowdonia Mountain weather forecast table
Confidence
High for unsettled and rather cold conditions with snow at times. Medium for details from Saturday.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
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.
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.
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.
Blizzards
Blizzards and whiteouts present challenging and serious conditions due to a combination of falling or blowing snow, strong winds and cold temperatures. They can be highly disorientating, often resulting in near-zero visibility with limited or no visual references and no distinction between ground and sky. Cliff edges and cornices may not be apparent, even close up. These conditions require very good navigational skills.
Heavy snow
Heavy snow can lead to rapid changes in underfoot conditions and paths may become treacherous or hidden. It also brings very poor visibility and often makes navigation much more challenging. When deep snow accumulates progress is often time consuming and strenuous, significantly affecting the distance one can travel on foot. Deep drifts can develop if snow is combined with strong winds. A heightened avalanche risk is possible and avalanche reports should be consulted where available.
Mountain weather forecast
Cloudy with outbreaks of rain, sleet and snow.
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
80% | 80% | 60% | 60% | 60% | 70% |
Wind direction and speed (mph)
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
S
33
|
S
31
|
SW
27
|
SW
24
|
SW
25
|
W
33
|
| 600m |
S
25
|
S
23
|
S
20
|
SW
18
|
SW
18
|
W
24
|
| 300m |
S
17
|
SE
14
|
S
12
|
SW
10
|
SW
10
|
W
15
|
| Valley |
S
17
|
S
15
|
S
12
|
SW
10
|
SW
10
|
W
14
|
Wind gust (mph)
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m | 39 | 39 | 35 | 31 | 33 | 43 |
| 600m | 31 | 30 | 27 | 24 | 25 | 34 |
| 300m | 28 | 27 | 23 | 21 | 22 | 31 |
| Valley | 28 | 29 | 22 | 22 | 22 | 29 |
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
-1°
|
0°
|
2°
|
2°
|
2°
|
1°
|
| 600m |
1°
|
2°
|
4°
|
4°
|
4°
|
3°
|
| 300m |
3°
|
4°
|
6°
|
6°
|
6°
|
5°
|
| Valley |
4°
|
5°
|
7°
|
8°
|
7°
|
6°
|
| Freezing Level |
800m
|
1,100m
|
1,300m
|
1,300m
|
1,200m
|
1,000m
|
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
-9°
|
-8°
|
-4°
|
-4°
|
-5°
|
-7°
|
| 600m |
-6°
|
-4°
|
-1°
|
-1°
|
-1°
|
-4°
|
| 300m |
-2°
|
0°
|
3°
|
3°
|
3°
|
1°
|
| Valley |
0°
|
1°
|
4°
|
5°
|
4°
|
2°
|
Additional weather information
Weather
Outbreaks of rain, sleet and snow during the day, occasionally heavy. Snow typically falling to around 400m at first, but steadily rising during the morning, mainly rain at all levels in the afternoon. Blizzard conditions possible at height during the morning with a severe wind chill. Becoming more showery by evening, but these gradually turning more wintry again.
Chance of cloud-free mountain/hill tops at 800m
10% or less through much of the day with the cloud extensive or overcast with bases around 600m, patches to 300m. Cloud tending to lift a little in the evening.
Ground conditions
Area - Snowdon Date - 10 December 2019 Time - 11.00am Snow Above - Report By - Snowdon Warden Route Taken PYG track Conditions Flooding on the paths. No snow and ice on paths. Essential Kit The following is a list of additional kit required based on the current conditions. Standard winter kit required.
Visibility
Moderate or poor in rain and sleet and very poor at times in snow and low cloud.
Meteorologist's view
Very poor conditions at times at height with whiteout and blizzard conditions possible for a short time in the morning.
Mountain weather information
Weather
Mostly cloudy with showers or longer outbreaks of rain, sleet and snow. The snow mainly above 800m, but lowering to 600m at times. Temporary blizzard conditions over the tops.
Chance of cloud-free mountain/hill tops at 800m
30%, extensive cloud with bases 600m to 800m, occasionally lower in rain, sleet and snow.
Maximum wind speed expected
West 45 gust 55mph
Temperature
- At 800m Around Zero Celsius
- Valley Plus 3 Celsius rising to 6 Celsius
- Freezing level Around 800m
Visibility
Mostly good or very good lower down, but moderate in rain. Poor or very poor at times at height.
Mountain weather information
Saturday 14 December
Sunrise:
Sunset:
Increasingly cloudy with showers or longer outbreaks of rain and snow developing Snow mainly above 400m. Strong to gale force winds over the tops with a severe wind chill and temporary blizzard conditions at times. Freezing level 500 to 800m.
Sunday 15 December
Sunrise:
Sunset:
Sunny intervals and occasional showers off rain, sleet and snow. Snow mainly above 600m. Strong to gale force winds over the tops. Freezing level around 600-800m.
Monday 16 December
Sunrise:
Sunset:
Bright with some sunny or clear spells, but occasional wintry showers possible. Moderate or fresh west or southwest winds over the tops. Freezing level around 600m, but lower early and later in the day.
Updated at:
Summit specific forecast
Mountain summit forecast map
Key
Mountain summits
Other points of interest
Cluster of multiple stations
The Snowdonia mountains are made up of 90 mountain peaks including the tallest mountain in Wales, Snowdon, standing at 1,085 metres.
The region can be divided into four areas with the northernmost area the most popular, including peaks such as Moel Hebog, Mynydd Mawr and the Nantlle Ridge. Many hikers tend to concentrate on Snowdon itself regarding it as a fine mountain. However it can become quite crowded, with the peak welcoming around half a million visitors every year, of which four fifths scale the peak on foot, while the remainder choose to take the train instead.
One of Snowdon’s main attractions is the sheer number and variety of paths that reach the peak. This means that everyone from mountaineering novices to climbing experts should find a way up the mountain that will suit their abilities or provide them with a sufficient test. The easiest is the Llanberis path which, being the longest, has the most shallow ascent. In contrast, the Watkin Path is widely seen as being the most demanding ascent, despite also being considered the prettiest.