Mountain weather
Yellow warning

Yellow weather warnings in force for Snowdonia

Snowdonia Mountain weather forecast table

Confidence

High confidence for the arrival of Storm Barra on Tuesday bringing severe gales.

Sunrise:
Sunset:
Mountain hazards

Mountain weather hazards

Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.

hazard Storm force winds
Storm force winds (gusts over 70mph) make walking very strenuous with any mobility virtually impossible over exposed ground. Where these conditions occur there is a high risk of being blown over and even standing may be impossible at times with a risk of being blown off one’s feet. Basic tasks such as using a map, eating, putting on extra clothing or communication become extremely difficult away from any shelter.
hazard 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.
hazard 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.

hazard 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.
hazard 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.
hazard 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.
hazard 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

A stormy day with severe gales for North Wales and a periods or rain, sleet and snow giving some very poor conditions.

06:00 09:00 12:00 15:00 18:00 21:00
Weather
(at 800m)
Partly cloudy (night) Heavy snow Heavy rain Heavy snow shower (day) Heavy snow shower (night) Heavy snow shower (night)
Chance of precipitation
(at 800m)
20% 40% >95% 60% 80% 80%

Wind direction and speed (mph)
Altitude above mean sea level
06:00 09:00 12:00 15:00 18:00 21:00
900m SE
31
SE
56
SE
59
S
50
S
58
S
47
600m SE
24
SE
42
SE
47
S
39
S
44
S
34
300m SE
16
SE
31
SE
33
S
26
S
31
S
22
Valley SE
16
SE
31
SE
34
S
26
S
31
S
22
Wind gust (mph)
Altitude above mean sea level
06:00 09:00 12:00 15:00 18:00 21:00
900m 36 66 72 62 73 60
600m 30 53 59 51 58 45
300m 28 49 54 45 53 40
Valley 28 49 55 44 52 40

Altitude above mean sea level
06:00 09:00 12:00 15:00 18:00 21:00
900m
-2°
-2°
-1°
-1°
600m
300m
Valley
Freezing Level
400m
600m
800m
800m
800m
800m

Altitude above mean sea level
06:00 09:00 12:00 15:00 18:00 21:00
900m
-10°
-12°
-11°
-10°
-11°
-10°
600m
-5°
-8°
-7°
-6°
-7°
-6°
300m
-2°
-5°
-3°
-1°
-4°
-2°
Valley
-3°
-2°
-2°

Additional weather information

Meteorologist's view

Extremely hazardous conditions on Tuesday with storm force gusts likely, particularly around mid-afternoon, 90mph will be possible higher on Snowdon. Note the extreme wind chill. Winds are also likely to cause blizzards conditions at times.

Weather

A brief brighter start to the day but winds strengthening soon after dawn and cloud beginning to thicken from the west. A band of heavy rain, sleet and some snow will spread across the area through the morning accompanied by severe gales and storm force gusts on higher peaks. Snow is likely above 200-300m initially but tending to become a mix of rain and sleet through the morning. A severe wind chill is expected with very poor conditions and a risk of blizzard conditions over the high ground. Rain will clear into the afternoon, to give generally brighter conditions but frequent wintry showers are soon expected, again accompanied by some very strong gusts, storm force on the tops, and there is a risk of blizzard conditions at times.

Chance of cloud-free mountain/hill tops at 800m

10% during the morning as the band of rain, sleet and snow crosses the area. Conditions improving to 40% during the afternoon, with some brightness but widespread showers

Visibility

Visibility rapidly deteriorating through the morning as widespread low cloud spreads across the areas, cloud bases are expected to be broken or overcast above around 400m. Very poor conditions are likely on the tops at times as sleet, snow and heavy rain moves through. Brief periods of better visibility are likely into the afternoon but any wintry showers will soon cause it to deteriorate again.

Ground conditions

Please see - https://www.eryri.llyw.cymru/visiting/walking/ground-conditions

Sunrise:
Sunset:

Mountain weather information

Weather

A stormy start to Wednesday with frequent snow showers above 800m and westerly gales continue overnight. This will continue for much of the day with some showers turning heavy and a risk of thunder too, showers will increasingly turn to sleet or rain by the end of the day. Winds ease slightly during the afternoon.

Chance of cloud-free mountain/hill tops at 800m

30% associated with frequent showers during the day, a few brighter spells but these will be hard to find.

Maximum wind speed expected

Westerly 35 gusting 50-60 mph to start, gradually easing and becoming northwesterly 30 gusting 40-45 mph later.

Temperature

  • At 800m Minus 1 rising to Plus 1 Celsius by evening.
  • Valley Plus 4 Celsius.
  • Freezing level 600m rising to 900m

Visibility

Cloud is likely to be broken above around 500m with some patchy cloud below this, particularly in the west and visibility poor in showers at times.

Mountain weather information

Thursday 9 December

Sunrise:
Sunset:

Some wintry showers at first but perhaps a few brighter spells appearing later. Freezing level around 8-900m. Strong northwesterly winds easing.

Friday 10 December

Sunrise:
Sunset:

Some outbreaks of rain/sleet and snow are likely in the morning but a few bright spells later, Freezing level around 800m. Northwesterly winds will become strong again.

Saturday 11 December

Sunrise:
Sunset:

A bright start but likely to be further frontal rain later, milder air is expected but strong or gale force southerly winds are also possible.

Updated at:

Summit specific forecast

Mountain summit forecast map

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.