Mountain weather

Snowdonia Mountain weather forecast table

Confidence

High for a drier week and for showers Sunday and Monday but lower confidence for timings and intensity of showers.

Sunrise:
Sunset:
Mountain hazards

Mountain weather hazards

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

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 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 Thunderstorms
Lightning is a significant mountain hazard which can result in serious injury or death. Mountain terrain often leaves one highly exposed to lightning strikes. Hail may give unpleasant conditions with torrential rain and localised flash flooding also possible, mainly in Summer months.

Mountain weather forecast

Bright with hazy sunshine and a few showers in morning, but heavy and perhaps thundery showers spreading from west in afternoon. Windy.

06:00 09:00 12:00 15:00 18:00 21:00
Weather
(at 800m)
Cloudy Cloudy Cloudy Cloudy Heavy rain Heavy rain
Chance of precipitation
(at 800m)
00% 10% 10% 30% 50% 70%

Wind direction and speed (mph)
Altitude above mean sea level
06:00 09:00 12:00 15:00 18:00 21:00
900m SW
30
SW
26
S
27
S
29
S
32
S
30
600m SW
18
S
15
S
19
S
20
S
21
S
21
300m SW
10
S
9
S
14
S
15
S
14
S
14
Valley SW
10
S
9
S
13
S
14
S
14
S
14
Wind gust (mph)
Altitude above mean sea level
06:00 09:00 12:00 15:00 18:00 21:00
900m 36 31 35 37 40 38
600m 25 20 26 28 29 29
300m 23 18 24 26 27 27
Valley 23 18 23 25 27 26

Altitude above mean sea level
06:00 09:00 12:00 15:00 18:00 21:00
900m
600m
300m
Valley
10°
10°
Freezing Level
1,200m
1,300m
1,200m
1,200m
1,300m
1,200m

Altitude above mean sea level
06:00 09:00 12:00 15:00 18:00 21:00
900m
-3°
-2°
-2°
-3°
-4°
-4°
600m
300m
Valley

Additional weather information

Meteorologist's view

Notable chill affect at height with strong winds and showers. Warm layers recommended.

Weather

A bright and mostly dry day, but generally cloudy, with large amounts of high cloud keeping sunshine hazy and a few showers possible. Becoming cloudier in the late afternoon with occasionally heavy and perhaps thundery showers after dusk.

Chance of cloud-free hill tops

80%, decreasing to 30% after dusk.

Low cloud and visibility

Mostly good visibility for much of the day with only patchy cloud at summit level. Falling to poor in showers later in the day with accompanying cloud obscuring tops above 500m.

Ground conditions

Please see - https://snowdonia.gov.wales/visit/snowdon/yr-wyddfa-ground-conditions-reports/

Sunrise:
Sunset:

Mountain weather information

Weather

Some showers overnight. Bright with sunny spells but also further showers through the day, these heavy and perhaps thundery at times. The heaviest showers potentially bringing transitory snow above 1000m. Showers becoming lighter and more confined to western parts in the evening. Mist and fog patches potentially forming in some eastern valleys by midnight.

Chance of cloud-free hill tops

60%

Maximum wind speed expected

Southerly 15-25mph at first, gradually veering to become northwesterly 10-15mph by mid-afternoon.

Temperature

  • At 800m Plus 3 Celsius
  • Valley Plus 6 Celsius rising to Plus 10 Celsius
  • Freezing level Just above the summits.

Low cloud and visibility

Cloud obscuring hills above 800m during showers, and down to 500m with heavier bursts through the morning. Good visibility out of showers, but poor when they occur, and potentially very poor briefly on the highest summits with any snow that occurs. Also becoming very poor at low levels in some eastern valleys.

Mountain weather information

Tue 29 Nov

Sunrise:
Sunset:

Dry, with sunny spells and light winds. Stronger winds developing on the summits, especially in the west. Freezing level falling to 1000m. Chance of mist and fog patches persisting in eastern valleys.

Wed 30 Nov

Sunrise:
Sunset:

Similar to Tuesday, with winds easing. Rain perhaps approaching from the west, but likely staying in the Irish Sea, with mist and fog reforming in eastern valleys. Freezing levels rising a little above the summits.

Thu 1 Dec

Sunrise:
Sunset:

Low confidence with rain perhaps extending eastwards, but most likely persisting to the west with most hills staying dry. Mist and fog persisting in some eastern valleys. Freezing level above summits.

Updated at:

Summit specific forecast

Mountain summit forecast map

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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.