Mountain weather

Snowdonia

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Snowdonia Mountain weather forecast table

Confidence

High confidence for transition from sunny weather Monday to unsettled conditions through the rest of the week. Lower for specific details of any thunderstorms.

This evening forecast

Sunrise:
Sunset:

A dry evening with some late sunshine and skies largely remaining clear into the night.

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.
Mountain hazards explained

Mountain weather forecast

Dry with long intervals of strong sunlight.

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

UV levels will be very high and there will be long intervals of clear skies, therefore remember to wear sun cream and stay hydrated through the day.

Weather

Clear skies to start the day, allowing the odd mist and fog patch to form in the valleys around dawn before quickly clearing. Dry with long intervals of sunshine through the morning. Patchy cloud will begin to build from around midday, giving the risk of an odd short-lived shower in the middle of the afternoon. Any showers that do form will fade into the evening, though the cloud will build more widely into the night.

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

90% for much of the day, falling to 70% in the late evening and night.

Visibility

Generally very good with excellent clarity, however locally poor in any valley fog around dawn. Any showers in the afternoon will briefly obscure views of nearby hills. Low cloud developing around 400-500m in the final few hours of the day, bringing poorer visibility particularly to southwestern slopes.

Ground conditions

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

Sunrise:
Sunset:

Mountain weather information

Weather

Cloudier in general on Tuesday with scattered showers soon spreading across the park in the early hours. These will continue throughout the day and into the evening, being heavy at times and bringing the risk of thunder and hail.

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

60% through the day.

Maximum wind speed expected

Winds on the summits initially southerly 10mph, transitioning to westerly through the afternoon with gusts speeds also increasing to 20mph.

Temperature

  • At 800m Plus 10 Celsius.
  • Valley Plus 14 Celsius, rising to plus 19 Celsius.
  • Freezing level Above the summits.

Visibility

Widely cloudy through the day, with bases intermittently falling to 300-400m and obscuring slopes and summits above this. Visibility also becoming poor in any showers, particularly if heavy and associated with hail.

Mountain weather information

Wednesday 28 July

Sunrise:
Sunset:

Clear spells at first, but scattered, heavy and thundery showers developing over the course of the day. Southwesterly winds, increasing in strength through the day.

Thursday 29 July

Sunrise:
Sunset:

Scattered showers and sunny spells. The showers may again by heavy with the risk of thunder. Breezy and gusty southwesterly winds.

Friday 30 July

Sunrise:
Sunset:

Remaining unsettled with continued scattered showers. Still the chance of them being heavy and thundery, but tending to ease through the day. Southwesterly winds remaining breezy.

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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