Mountain weather

Mountain weather

Bannau Brycheiniog / Brecon Beacons

Confidence

High for the overall theme. Lower confidence for any heavy downpours on Friday.

Mountain hazards

Mountain weather hazards

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

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.
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

Often cloudy with showers by the afternoon.

Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
Weather
(at 800m)
Weather symbols Cloudy Light rain Light rain Light rain showers Heavy rain showers Cloudy
Chance of
precipitation
(at 800m)
Chance of precipitation
30%
20%
20%
60%
60%
30%

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 SE 7mph knots
SE
7mph
SE 11mph knots
SE
11mph
SE 9mph knots
SE
9mph
S 9mph knots
S
9mph
S 4mph knots
S
4mph
E 8mph knots
E
8mph
300m
300m E 2mph knots
E
2mph
E 5mph knots
E
5mph
SE 6mph knots
SE
6mph
SE 4mph knots
SE
4mph
SE 5mph knots
SE
5mph
E 4mph knots
E
4mph
Valley
Valley E 2mph knots
E
2mph
E 6mph knots
E
6mph
SE 7mph knots
SE
7mph
SE 4mph knots
SE
4mph
SE 5mph knots
SE
5mph
E 3mph knots
E
3mph

Wind gust

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
600m
600m 9mph 14mph 13mph 12mph 8mph 10mph
300m
300m 6mph 10mph 12mph 8mph 8mph 9mph
Valley
Valley 7mph 11mph 14mph 8mph 8mph 9mph

Altitude above mean sea level
Time
Time
06:00
09:00
12:00
15:00
18:00
21:00
600m
600m 4 degrees Celsius 4 degrees Celsius 7 degrees Celsius 10 degrees Celsius 10 degrees Celsius 7 degrees Celsius
300m
300m 8 degrees Celsius 8 degrees Celsius 11 degrees Celsius 14 degrees Celsius 11 degrees Celsius 8 degrees Celsius
Valley
Valley 8 degrees Celsius 9 degrees Celsius 12 degrees Celsius 14 degrees Celsius 12 degrees Celsius 10 degrees Celsius
Freezing Level Freezing Level
1400m
1700m
1600m
1800m
1900m
1800m

Additional weather information

Meteorologist's view

Poor conditions to start with good navigational skills required. UV still strong despite cloud cover so sun protection advised as well as a waterproof if caught in a heavy downpour.

Weather

Cloudy through the early hours with outbreaks of rain. Drier thereafter with warm sunny spells developing in the afternoon, but always with the risk of a shower, heaviest to the east of the park though mostly dry. These fading by the evening with clearer skies into the night.

Chance of cloud-free hill tops

60% rising to 90% by midday.

Low cloud and visibility

Patchy cloud around 400-500 m initially, then gradually lifting above summits by midday. Poor visibility first thing in rain then very good by the afternoon. Dropping in any sharp showers.

Ground conditions

No recent ground conditions report available.

Summit specific forecast