Bannau Brycheiniog (Brecon Beacons) mountain weather forecast.

The central Beacons, Black Mountains and Fforest Fawr. Height-aware guidance for wind, cloud, rain and temperature.

Mountain Weather brief

Bannau Brycheiniog (Brecon Beacons)

Sunday 30 August 2026 · The central Beacons, Black Mountains and Fforest Fawr

Confidence: Medium

Why: Thunderstorm timing is inherently uncertain and may shift by several hours.

What matters most

Thunderstorms are the main concern, especially on exposed summits and ridges. A noticeable southwesterly breeze and Persistent rain.

High-ground wind · 700 m15–20 mph southwesterly Gusts · 700 m30 mph Cloud base400-900 m Feels like · 700 m7°C
Morning · 07:00–13:00PoorSome early summit cloud is possible.
44/100
Afternoon & evening · 13:00–22:00Poor
30/100

Conservative regional grades across representative summits, so one sheltered hill does not overstate the wider area.

01

High-ground wind (700 m)

Southwesterly 15-20 mph at 700 m. Gusts reaching around 30 mph at 700 m, with locally higher values possible on the most exposed tops. Starting nearer 10 mph, then strengthening toward 15 mph later.

02

Walking impact

Noticeable on exposed ground, but unlikely to impede most walking.

03

Thunderstorms

A high thunderstorm risk is indicated from the morning into the evening. Avoid committing to exposed summits or ridges while storms are building or nearby.

04

Ground conditions

The ground is likely to be saturated after recent rain. Expect boggy paths and rapid runoff if more rain arrives.

05

Spate risk

High spate risk based on forecast rainfall. Burns and unbridged crossings may become difficult or impassable. The heaviest rain is expected later in the day. Crossing risk is expected throughout the day, continuing overnight and easing after around 04:00 the following morning. Turn back if a crossing looks unsafe.

06

Rain and showers

Persistent rain for much of the day. The heaviest rain is expected later in the day.

07

Cloud-free summits

Around 50%. Around 55% early, falling to around 45% later.

08

Cloud and visibility

Cloud bases mostly around 400-700 m. More summits are likely to become shrouded later. Cloud is likely to come and go on the higher summits; breaks may be useful but not dependable.

09

Temperature and wind chill

Around 11°C at 700 m, feeling like 7°C in the wind.

10

Freezing level

Above the summits.

11

Daylight

Sunrise 06:21 — Sunset 20:06 — about 13.7 hours daylight.

Overnight · 6 p.m.–9 a.m.Wild campingBetaThunder risk is around 53% in parts of the area; avoid exposed pitches if storms develop. 32/100Poor · 600 m View detailsHide details
Regional night beginning Sunday 30 August 2026

Full regional overnight outlook

Across representative hills, open-hillside camping looks poor around 600 m (32/100). A wet night is likely, with around 23 mm indicated between pitching and packing up.

Overnight rain23 mmOpen ground · 600 m13 mph · gusts 25 mphMorning pack-upDampness possible
300 m36/100 · poor
Wind / gust
11 / 21 mph
Coldest
11.0°C
In cloud
Unlikely
Condensation
High
600 m32/100 · poor
Wind / gust
13 / 25 mph
Coldest
10.1°C
In cloud
56% of night
Condensation
High

The ground is likely to be very wet after recent rain; expect boggy approaches and choose a durable pitch carefully.

Open-hillside guidance across representative hills. Local shelter, ridges, tent design and the exact pitch can change conditions substantially. Read about sleeping-bag comfort ratings, pitching in strong winds or using the wild-camping forecast.

Daytime · exposed rockClimbing & scramblingBetaThunder risk is around 49% in parts of the area; exposed scrambling may be a poor choice. 7/100Poor · Very poor View detailsHide details
Across representative exposed-rock terrain

Full regional climbing & scrambling outlook

Conditions for exposed scrambling across the area look very poor (7/100). Rain is likely to leave rock wet; polished slabs, vegetation and drainage lines may be notably worse. Gusts may reach about 30 mph on exposed ground, making crosswinds an important route consideration. Mapped summit-point geology across the representative hills includes sandstone or gritstone; moisture response can therefore vary substantially between crags and routes.

Rock surfaceWet rock likelyExposed gust29 mphRain15.4 mm
Mapped rock across sampled summits1 broad familyRepresentative summit samples
sandstone or gritstone 100% 8 representative summitsUsually rough and grippy when dry. Damp sandstone and gritstone can feel greasy, and saturated sandstone may be weakened, so let the rock dry fully.

Representative summit-point samples across the region; individual crags and routes may differ.

Generic exposed hands-on-rock terrain across representative summits; mapped summit-point geology is a broad regional sample, not a named-route survey. Contains British Geological Survey materials © UKRI 2026. How to use the climbing and scrambling forecast.

Updated 30 August 2026 at 04:40 UTC. See typical weekly and monthly conditions for Bannau Brycheiniog (Brecon Beacons).

Stay near Bannau Brycheiniog (Brecon Beacons).

Use Pen y Fan as a practical starting point for whole-home stays with a useful drive to established walking routes.

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