Mountain weather

Eryri / Snowdonia

Eryri / Snowdonia Mountain weather forecast table

Confidence

Usual uncertainties in distribution and organisation of shower bands.

Sunrise:
Sunset:

This evening forecast

A blustery end to the day with a mix of dry spells and showers. Some showers could be heavy with some hail and thunder, and may bring some sleet to the tops of peaks.

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 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 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 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 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.

Mountain weather forecast

Winds gradually easing. Showers to start then turning drier with sunny spells.

Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
Weather
(at 800m)
Light snow Light snow Light snow Light snow Heavy snow shower (day) Heavy snow shower (day) Light snow Light snow
Chance of precipitation
(at 800m)
00% 00% 00% 00% 00% 00% 00% 00%

Wind direction and speed (mph)
Altitude above mean sea level
Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
900m SW
46
SW
42
SW
37
SW
35
SW
31
SW
30
SW
23
SW
17
600m SW
32
SW
28
SW
23
SW
27
SW
24
SW
23
SW
16
SW
11
300m SW
17
SW
16
SW
16
SW
19
SW
17
SW
16
SW
11
S
7
Valley SW
18
SW
16
SW
16
SW
19
SW
16
SW
16
SW
11
S
7
Wind gust (mph)
Altitude above mean sea level
Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
900m 56 51 45 44 39 39 29 21
600m 41 36 31 36 32 31 21 15
300m 32 30 29 32 29 27 20 14
Valley 33 30 29 31 27 27 19 14

Altitude above mean sea level
Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
900m
600m
300m
Valley
10°
Freezing Level
1,100m
1,100m
1,000m
1,000m
1,000m
1,000m
900m
800m

Altitude above mean sea level
Time 00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00
900m
-8°
-7°
-7°
-7°
-5°
-5°
-6°
-5°
600m
-3°
-3°
-2°
-2°
-1°
-1°
-1°
-1°
300m
Valley

Additional weather information

Meteorologist's view

A chilly and blustery day ahead so layers and waterproofs advised.

Weather

A blustery start with showers merging into longer spells of rain through the early hours. Showers generally less frequent than on Saturday with sunny spells more widespread. Any showers still could be heavy with the odd rumble of thunder. Winds also gradually easing.

Chance of cloud-free hill tops

60% early on, otherwise 80%.

Low cloud and visibility

Patchy low cloud early on down to 500-700 m, otherwise cloud above summits. Very poor initially then rising to good or very good outside showers.

Ground conditions

Please see - https://yrwyddfa.live/

Sunrise:
Sunset:

Mountain weather information

Weather

A chilly start. Winds much lighter than recent days though the risk of showers continues. These will tend to be scattered across the park at times during the day, and may turn heavy. Plenty of sunny spells in between any showers. Temperatures similar to Sunday but feeling more pleasant in lighter winds.

Chance of cloud-free hill tops

60% early on, otherwise 80%.

Maximum wind speed expected

10-15 mph.

Temperature

  • At 800m Plus 4 Celsius rising to 10 Celsius.
  • Valley Minus 2 Celsius rising to plus 10 Celsius.
  • Freezing level Just above summits.

Low cloud and visibility

Patchy low cloud early on down to 600-700 m, otherwise cloud above summits. Cloud bases may drop briefly in any heavier downpours. Poor visibility to start but then becoming good or very good visibility outside of showers.

Mountain weather information

Tue 14 Apr

Sunrise:
Sunset:

Fine and dry during the early hours but cloud bases lowering as patchy outbreaks of rain and drizzle move in from the west through the day. Freezing level above summits. Light winds.

Wed 15 Apr

Sunrise:
Sunset:

Wet and windy with heavy outbreaks of rain creating very poor visibility across the park at times alongside low cloud bases. Moderate to strong southerly winds.

Thu 16 Apr

Sunrise:
Sunset:

Returning to sunshine and showers. Lighter winds.

Updated at:

Summit specific forecast

Mountain summit forecast map

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