Mountain weather

Mountain weather

Bannau Brycheiniog / Brecon Beacons

Confidence

High confidence in the overall weather but precise shower detail and timing remains lower confidence.

Mountain hazards

Mountain weather hazards

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

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.

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.
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.
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 weather forecast

Heavy, blustery showers and some brighter spells.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Heavy rain showers Heavy rain showers Heavy rain showers Heavy rain showers Heavy rain showers Heavy rain showers (night)
Chance of
precipitation
(at 800m)
Chance of precipitation
80%
90%
90%
90%
90%
90%

Wind direction and speed

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
600m
600m W 22mph knots
W
22mph
W 23mph knots
W
23mph
NW 25mph knots
NW
25mph
NW 24mph knots
NW
24mph
NW 20mph knots
NW
20mph
NW 18mph knots
NW
18mph
300m
300m W 13mph knots
W
13mph
W 15mph knots
W
15mph
NW 17mph knots
NW
17mph
NW 16mph knots
NW
16mph
NW 12mph knots
NW
12mph
W 9mph knots
W
9mph
Valley
Valley W 11mph knots
W
11mph
W 15mph knots
W
15mph
NW 15mph knots
NW
15mph
NW 14mph knots
NW
14mph
NW 11mph knots
NW
11mph
W 8mph knots
W
8mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
600m
600m 28mph 31mph 33mph 32mph 27mph 25mph
300m
300m 27mph 30mph 32mph 31mph 24mph 19mph
Valley
Valley 26mph 30mph 32mph 30mph 24mph 19mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
600m
600m -2 degrees Celsius -1 degrees Celsius 0 degrees Celsius 1 degrees Celsius 1 degrees Celsius -1 degrees Celsius
300m
300m 3 degrees Celsius 4 degrees Celsius 5 degrees Celsius 6 degrees Celsius 5 degrees Celsius 3 degrees Celsius
Valley
Valley 4 degrees Celsius 5 degrees Celsius 6 degrees Celsius 8 degrees Celsius 7 degrees Celsius 4 degrees Celsius
Freezing Level Freezing Level
1000m
1000m
1100m
1100m
1100m
1100m

Additional weather information

Meteorologist's view

Frequent and locally heavy showers will bring a very changeable day. Care needed if heading into the hills with temperatures feeling cold at height, some gusty winds and a risk of thunder. UV levels also remaining high in any brighter spells.

Weather

Blustery showers on Wednesday with some heavy downpours. Showers could fall as hail at times with a small risk of thunder. Some clear or sunny spells likely, but skies often quickly cloud. There is also a small risk of thunderstorms, particularly during the afternoon.

Chance of cloud-free hill tops

70% becoming 90% into the morning.

Low cloud and visibility

There may be a little cloud with bases 500-600m to start, quickly rising above all summits into the morning. Visibility will generally be very good, although falling rapidly within any heavy showers to become moderate to poor.

Ground conditions

No recent ground conditions report available.

Summit specific forecast