Mountain weather

Mountain weather

Eryri / Snowdonia

Confidence

Generally high for the overall evolution, but medium for the detail regards to rainfall and cloud on Sunday.

Sunrise: Sunset:
Sunrise: Sunset:
Mountain hazards

Mountain weather hazards

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

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.

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.
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.

Mountain weather forecast

Outbreaks of rain easing during the afternoon.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Light rain Light rain Light rain Light rain Light rain Cloudy
Chance of
precipitation
(at 800m)
Chance of precipitation
<5%
<5%
<5%
<5%
<5%
<5%

Wind direction and speed

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m W 12mph knots
W
12mph
W 8mph knots
W
8mph
W 10mph knots
W
10mph
SW 11mph knots
SW
11mph
SW 12mph knots
SW
12mph
S 14mph knots
S
14mph
600m
600m SW 8mph knots
SW
8mph
SW 6mph knots
SW
6mph
SW 8mph knots
SW
8mph
SW 9mph knots
SW
9mph
S 10mph knots
S
10mph
S 12mph knots
S
12mph
300m
300m S 2mph knots
S
2mph
NW 2mph knots
NW
2mph
W 6mph knots
W
6mph
W 6mph knots
W
6mph
S 6mph knots
S
6mph
S 7mph knots
S
7mph
Valley
Valley S 2mph knots
S
2mph
NW 2mph knots
NW
2mph
W 6mph knots
W
6mph
W 6mph knots
W
6mph
S 5mph knots
S
5mph
S 6mph knots
S
6mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 14mph 11mph 14mph 15mph 15mph 17mph
600m
600m 10mph 9mph 11mph 12mph 13mph 15mph
300m
300m 6mph 4mph 9mph 10mph 10mph 14mph
Valley
Valley 6mph 4mph 9mph 10mph 9mph 13mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
900m
900m 9 degrees Celsius 10 degrees Celsius 10 degrees Celsius 10 degrees Celsius 9 degrees Celsius 9 degrees Celsius
600m
600m 12 degrees Celsius 12 degrees Celsius 13 degrees Celsius 13 degrees Celsius 12 degrees Celsius 11 degrees Celsius
300m
300m 15 degrees Celsius 16 degrees Celsius 17 degrees Celsius 16 degrees Celsius 15 degrees Celsius 14 degrees Celsius
Valley
Valley 16 degrees Celsius 17 degrees Celsius 18 degrees Celsius 18 degrees Celsius 17 degrees Celsius 15 degrees Celsius
Freezing Level Freezing Level
2700m
2700m
3000m
3100m
3100m
3700m

Additional weather information

Meteorologist's view

Low cloud and poor visibilities make navigation challenging, combined with wet surfaces and rain, suitable clothing is a necessity.

Weather

A wet start with any residual outbreaks of heavy rain easing to become patchier and lighter through the morning and into the afternoon but remaining largely cloudy through the day. Perhaps with some brighter spells developing later in the day. Winds also easing.

Chance of cloud-free hill tops

10% or less at first becoming 50% into the afternoon.

Low cloud and visibility

Extensive low cloud around 500-600 m but cloud bases lowering towards 400 m in the heaviest rain. Generally poor to very poor visibility in rain and low cloud, but good outside of low cloud.

Ground conditions

No recent ground conditions report available.

Summit specific forecast