Mountain weather

Eryri / Snowdonia

Eryri / Snowdonia Mountain weather forecast table

Confidence

Medium for the detail of worst conditions.

Sunrise:
Sunset:
Mountain hazards

Mountain weather hazards

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

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.
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 Heavy Persistent 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 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.

Mountain weather forecast

Largely cloudy with showers or longer spells of rain and summit snow into the day. Strong to gale force summit winds.

06:00 09:00 12:00 15:00 18:00 21:00
Weather
(at 800m)
Light snow Sunny intervals Heavy snow Heavy shower (day) Heavy shower (day) Heavy snow shower (night)
Chance of precipitation
(at 800m)
80% 20% 70% 80% 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 S
24
S
25
SE
29
SE
26
S
15
SW
30
600m S
18
S
19
SE
24
SE
20
S
10
SW
21
300m S
11
S
12
SE
18
SE
15
W
7
SW
14
Valley S
11
S
12
SE
17
SE
15
SW
7
SW
15
Wind gust (mph)
Altitude above mean sea level
06:00 09:00 12:00 15:00 18:00 21:00
900m 28 30 37 33 19 38
600m 22 24 32 27 15 29
300m 19 19 30 25 13 26
Valley 19 20 29 25 13 27

Altitude above mean sea level
06:00 09:00 12:00 15:00 18:00 21:00
900m
-2°
-2°
600m
300m
Valley
Freezing Level
600m
600m
900m
1,100m
1,000m
1,000m

Altitude above mean sea level
06:00 09:00 12:00 15:00 18:00 21:00
900m
-9°
-10°
-7°
-6°
-5°
-7°
600m
-6°
-6°
-3°
-2°
-1°
-4°
300m
-3°
-1°
Valley
-1°

Additional weather information

Meteorologist's view

Severe wind chill restricted above mid-level routes, but still a feeling cold at lower levels with frequent showers giving little time for conditions to dry into the afternoon.

Weather

Overnight rain and snow clearing north to start the day with some brighter spells into the morning. Cloud thickening into the afternoon however as strengthening winds bring frequent showers or longer periods of rain and sleet into the remainder of the day. These likely to turn heavy at times with the risk of thunder. Hail is likely at low levels and sleet or snow likely above around 600-700m initially, becoming restricted to above 800-900m by the latter afternoon.

Chance of cloud-free hill tops

20% initially, becoming 80% by mid-morning before lowering to 30% into the afternoon.

Low cloud and visibility

Widespread cloud above 200-300m initially, this tending to lift and break somewhat into the morning but thickens once again through the afternoon to give widespread cloud above 500-600m. Visibility generally good but becoming increasingly moderate or poor in rain, very poor in snow and within cloud.

Ground conditions

Please see - https://yrwyddfa.live/

Sunrise:
Sunset:

Mountain weather information

Weather

Brighter spells and showers with outbreaks building into the afternoon, bringing a risk of hail and thunder. Snow level around 900m.

Chance of cloud-free hill tops

60% for any given time but very low for extended clear periods.

Maximum wind speed expected

South 20-25mph with gusts reaching 40mph across most exposed ridges and summits

Temperature

  • At 800m Plus 2 Celsius
  • Valley Plus 1 Celsius increasing 14 Celsius during the afternoon
  • Freezing level Above summits

Low cloud and visibility

Good or very good becoming moderate or poor in rain, very poor snow and within cloud with bases occasionally down to 600m.

Mountain weather information

Sat 30 Mar

Sunrise:
Sunset:

Sunshine and some scattered showers, mostly light but some sharper ones developing for the afternoon. Southerly summit breezes easing light later. Freezing level above all summits.

Sun 31 Mar

Sunrise:
Sunset:

Dry, sunny start. Cloud building from mid-day with increasing chance of rain later. Light winds. Freezing level above all summits.

Mon 1 Apr

Sunrise:
Sunset:

Overcast with occasional rain, though most of this light. Freezing level above all summits. Winds light

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 Yr Wyddfa (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 Yr Wyddfa's (Snowdon) 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.