Mountain weather

Snowdonia

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Snowdonia Mountain weather forecast table

Confidence

High for the general theme, falling to moderate for the extent of showers Monday and Tuesday.

Sunrise:
Sunset:
Mountain hazards

Mountain weather hazards

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

hazard Strong sunlight
Harmful UV levels from sunlight increase with altitude giving a greater risk of sunburn and eye damage, even on some overcast days. On breezy days, the cooling effect of wind on exposed skin may disguise any feeling of sunburn until it is too late. If there is snow cover, glare increases the effect of UV rays especially on the eyes. It is advisable to wear sun block, protective clothing such as a long-sleeved top and hat and have good quality eye protection.

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 hazards explained

Mountain weather forecast

Largely dry with sunny spells, scattered showers possible mid-afternoon on Monday.

Wind direction and speed (mph)
Altitude above mean sea level
Wind gust (mph)
Altitude above mean sea level

Altitude above mean sea level

Altitude above mean sea level

Additional weather information

Meteorologist's view

A bright start on Monday but with cloud banks near some summits good navigation skills will be required if heading out into the hills early in the day. Conditions improve during the morning with some strong sunshine and thus high UV levels, so sun protection is also needed. In additional there is also a risk of passing showers during the afternoon, so wet weather gear is advised.

Weather

Dry start to the morning on Monday and a bright start to the day. Cloud bubbling up during the course of the morning with a few isolated showers possible from late morning onwards. Any showers easing during the afternoon and evening leaving Snowdonia with clear spells into the overnight period.

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

80% reducing to 60% from late-morning.

Visibility

Generally good, however risk of some cloud banks near summits early in the morning but these mostly lifting, Shreds of cloud with bases from 700-800m may reduce visibilities near summits at times during the afternoon, in addition passing showers may result in the sudden deterioration of visibilities at times.

Ground conditions

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

Sunrise:
Sunset:

Mountain weather information

Weather

Generally dry and bright with sunny spells across Snowdonia, small risk of a few scattered showers developing during the day. Cloud increasing from the west from late afternoon.

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

80% throughout.

Maximum wind speed expected

Westerly or Southwesterly 10-15mph.

Temperature

  • At 800m Plus 7 Celsius, rising to plus 11 Celsius.
  • Valley Plus 9 Celsius, rising to plus 16 Celsius.
  • Freezing level Above the summits.

Visibility

Generally good with cloud bases above the level of summits however sudden deterioration in the visibility are possible in any showers. Visibilities below the cloud will often be good with excellent air clarity.

Mountain weather information

Wednesday 4 August

Sunrise:
Sunset:

Showery rain across the park spreading east during the day, risk of some heavy and thundery showers during the afternoon, light south westerly winds, freezing levels above summits..

Thursday 5 August

Sunrise:
Sunset:

Dry start with cloud increasing from the west with outbreaks of rain moving across Wales during the day, winds southerly and moderate, but confidence is low.

Friday 6 August

Sunrise:
Sunset:

Low confidence but any rain clearing though the morning, then sunny spells and scattered showers.

Updated at:
Mountain weather explained

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.

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