Mountain weather

Snowdonia Mountain weather forecast table

Confidence

High for general developments. Medium for precise timings of the band of rain today.

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 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.

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

Wet and very windy morning, becoming brighter with showers.

06:00 09:00 12:00 15:00 18:00 21:00
Weather
(at 800m)
Light rain Heavy rain Heavy rain Heavy shower (day) Heavy shower (night) Light shower (night)
Chance of precipitation
(at 800m)
60% 80% 70% 60% 40% 30%

Wind direction and speed (mph)
Altitude above mean sea level
06:00 09:00 12:00 15:00 18:00 21:00
900m SW
50
W
38
W
29
W
27
W
30
W
28
600m SW
34
SW
27
SW
20
W
20
W
18
W
17
300m SW
21
W
17
SW
13
W
15
W
12
W
12
Valley SW
21
W
17
SW
13
W
15
W
13
W
13
Wind gust (mph)
Altitude above mean sea level
06:00 09:00 12:00 15:00 18:00 21:00
900m 60 48 38 36 37 36
600m 43 36 27 27 27 24
300m 37 31 23 25 25 24
Valley 37 31 23 26 26 25

Altitude above mean sea level
06:00 09:00 12:00 15:00 18:00 21:00
900m
600m
10°
300m
12°
11°
11°
11°
10°
Valley
14°
12°
13°
13°
11°
10°
Freezing Level
2,100m
2,100m
1,700m
1,600m
1,400m
1,400m

Altitude above mean sea level
06:00 09:00 12:00 15:00 18:00 21:00
900m
-1°
-2°
600m
300m
Valley
10°
10°
10°
10°

Additional weather information

Meteorologist's view

A challenging and changeable day expected with some early navigational difficulties. Some poor conditions likely on the hills as the main rain band comes through and the forecast should be monitored in case of any changes. Strong winds are likely for exposed tops with gusts of 50-60mph likely over the higher summits, particularly as the heaviest rain moves through. Temperatures also falling into the afternoon with a significant wind-chill developing at height.

Weather

Largely cloudy through the morning, windy with frequent though generally light showers. A band of heavier rain and some strong gusty winds sinks southeast across the country however, and this is expected to bring a few hours of more persistent rain. This rain moving into the northwest of the range from around 08:00/09:00, and clearing around 11:00/12:00. In its wake brighter but fresher conditions with frequent showers pushing in from the west through the afternoon and into the evening, these locally heavy with a risk of hail and thunder. Strong to gale force summit winds with a significant wind chill into the afternoon.

Chance of cloud-free hill tops

Nil to 20% for much of the morning becoming 80% by afternoon as more persistent rain clears, although cloud lowering in any showers.

Low cloud and visibility

Fairly extensive cloud with bases locally down to 300-500m through the morning, particularly for western parts of the range. Visibility moderate or poor in rain, and locally very poor at height in hill fog. Both cloud bases and visibilities improving markedly as rain clears late afternoon becoming generally very good, though localised poor visibilities and cloud bases down to around 500-600m in association with showers.

Ground conditions

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

Sunrise:
Sunset:

Mountain weather information

Weather

Bright with occasional sunny spells and a scattering of showers early in the day. Fresh westerly winds at height but tending to ease somewhat into the day.

Chance of cloud-free hill tops

90%

Maximum wind speed expected

Westerly 20mph gusting 30mph.

Temperature

  • At 800m Plus 3 to 6 Celsius
  • Valley Plus 7 rising to 15 Celsius
  • Freezing level Above the summits

Low cloud and visibility

Occasional or patchy cloud mainly above the summits. Visibility mainly very good, but moderate or poor in any showers.

Mountain weather information

Sun 9 Oct

Sunrise:
Sunset:

Dry and bright. Freshening south or southwest winds, becoming strong later in the day. Rain likely overnight into Monday.

Mon 10 Oct

Sunrise:
Sunset:

Rain clearing overnight. Mainly dry and bright during daylight hours with sunny spells. Light or moderate northwest winds at height.

Tue 11 Oct

Sunrise:
Sunset:

Looking cloudier with the risk of a light shower. Light and variable winds.

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.