Mountain Weather
Information Service
Brecon Beacons Forecast

Brecon Beacons

Includes all higher summits in the southern half of Wales: the Bannau Brycheiniog / Brecon Beacons National Park, southern Cambrian Mountains and highest Preseli hills.

Saturday's Forecast

Windy, walking impeded
Frequent or persistent rain
Chilly

Click an icon for more information or click here for a key to all icons.

Click here to download the latest PDF Last Updated Fri 12th Sep 25 at 4:29PM Last Updated Fri 12th Sep 25 at 4:29PM
View our low-graphics version Last Updated Fri 12th Sep 25 at 4:29PM Last Updated Fri 12th Sep 25 at 4:29PM

Viewing Forecast For

Brecon Beacons
Saturday 13th September 2025
Last updated Fri 12th Sep 25 at 4:29PM

Summary for all mountain areas

Showery south-westerly airflow across the mountains. Most frequent showers western hills, where they will band into prolonged rain for a time with heavy or even torrential bursts. Scattered heavy showers spreading to eastern mountains too. Risk of thunder. Cloud shrouding western hills, occasional further east.

Headline for Brecon Beacons

Blustery and showery day with a marked chill. Cloud frequent higher areas.

How windy? (On the summits)

Southwesterly 25 to 40mph, speeds likely to vary during day.

Effect of the wind on you?

Frequently strenuous walking on high terrain, affecting balance on exposed tops and ridges. Considerable wind chill.

How Wet?

Frequent heavy showers

Clusters of showery rain, merging to be more constant rain for periods. Heavy bursts on and off, risk of hail and thunder. Tending to become more well scattered from west in afternoon, but still a focus around coastal hills.

Cloud on the hills?

Varied over high tops

Cloud base frequently changing, mostly confined to higher summits, bases typically 700-800m. Breaks to tops more often toward east, best afternoon.

Chance of cloud free summits?

40%

Sunshine and air clarity?

Brief glimpses of sun mostly in east Wales. Visibility often reduced by rain, intermittently good.

How Cold? (at 750m)

6 or 7C. Feeling sub-zero, around -4C on highest tops directly in the wind.

Freezing Level

Above the summits

Viewing Forecast For

Brecon Beacons
Sunday 14th September 2025
Last updated Fri 12th Sep 25 at 4:29PM

How windy? (On the summits)

South to south-easterly, later veering southwesterly, in the range of 40 to 60mph, through the day.

Effect of the wind on you?

A very turbulent day on the hills. Significant wind chill and buffeting leading to widely difficult conditions.

How Wet?

Very wet

Rainfall constant for much of the day, and often heavy with scope for some torrential bursts to develop. May ease from the west toward dusk. Scope for thunder.

Cloud on the hills?

Extensive

Be prepared for cloud to be extensive for much of the day, with limited if any breaks. Bases varying around 500-800m.

Chance of cloud free summits?

20%

Sunshine and air clarity?

Mostly overcast. Visibility often poor due to rain.

How Cold? (at 750m)

8C lifting to 11C

Freezing Level

Above the summits

Viewing Forecast For

Brecon Beacons
Monday 15th September 2025
Last updated Fri 12th Sep 25 at 4:29PM

How windy? (On the summits)

West to south-westerly 45 to 60mph, may reach 70mph for a time.

Effect of the wind on you?

Be prepared for difficult or very difficult conditions much of the day, with significant wind chill and buffeting.

How Wet?

Frequent showers

Frequent showers, often heavy, will drive in from the west through the day.

Cloud on the hills?

Most likely extensive.

Varying bases, but often around 600-800m, covering the the hills in cloud. Occasionally patches below 500m.

Chance of cloud free summits?

20%

Sunshine and air clarity?

Glimpses of sun, mostly in the east. Visibility sometimes poor due to rain.

How Cold? (at 750m)

8C

Freezing Level

Above the summits

Planning Outlook

Staying unsettled and cyclonic through into next week with temperatures staying on the cool side, often feeling below freezing in exposure to wind on higher terrain. During Sunday and into Monday, a deeper Atlantic low is expected to move in, bringing more extensive heavy rain northwards and gales - the strongest wind probably focused on England & Wales. Some improvement expected for a time into middle of next week, but the longer range outlook into late September remains unsettled.