Mountain weather
Bannau Brycheiniog / Brecon Beacons Mountain weather forecast table
Confidence
High for the changeable theme continuing this week with periods of wet and windy weather and some drier and brighter interludes. Lower confidence for details and timings of rainfall after Wednesday.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
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.
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.
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.
Mountain weather forecast
Unsettled with heavy, persistent rain and poor visibility.
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 600m) |
|
|
|
|
|
|
Chance of precipitation (at 600m) |
>95% | >95% | 80% | 80% | 80% | 80% |
Wind direction and speed (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 600m |
SW
31
|
SW
32
|
SW
27
|
SW
24
|
SW
22
|
SW
22
|
| 300m |
SW
19
|
SW
20
|
SW
17
|
SW
14
|
SW
13
|
SW
13
|
| Valley |
SW
16
|
SW
17
|
SW
14
|
SW
12
|
SW
11
|
SW
11
|
Wind gust (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 600m | 38 | 41 | 36 | 32 | 29 | 29 |
| 300m | 38 | 39 | 33 | 29 | 27 | 26 |
| Valley | 37 | 37 | 31 | 27 | 25 | 25 |
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 600m |
13°
|
14°
|
14°
|
14°
|
14°
|
14°
|
| 300m |
14°
|
15°
|
16°
|
16°
|
16°
|
16°
|
| Valley |
15°
|
16°
|
17°
|
17°
|
16°
|
16°
|
| Freezing Level |
3,300m
|
3,800m
|
3,800m
|
3,800m
|
3,800m
|
3,500m
|
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 600m |
8°
|
8°
|
10°
|
10°
|
11°
|
10°
|
| 300m |
11°
|
12°
|
13°
|
14°
|
14°
|
14°
|
| Valley |
12°
|
13°
|
14°
|
15°
|
15°
|
14°
|
Additional weather information
Meteorologist's view
A very wet autumnal day with poor visibilities. Treacherous conditions expected, slippery underfoot with waterlogged ground, so waterproofs will be a necessity. Strong winds expected, with buffeting on the summits.
Weather
Heavy and persistent rain throughout much of the day, perhaps turning lighter into the second half of the afternoon. Strong winds with gales likely over the summits.
Chance of cloud-free hill tops
Less than 10%
Low cloud and visibility
Widespread low cloud down 300-400 m, dropping down to 200 m in the heaviest downpours. Very poor visibility throughout.
Recent rainfall
Location: Neuadd (Near Pontsticill)
Altitude: 353m
| Last 24 hours | Last 48 hours | Last 72 hours |
|---|---|---|
| 6.8mm | 13.8mm | 46.2mm |
Measurement date:
Rainfall data provided by Natural Resources Wales. The Met Office is not responsible for content provided by third parties and may remove this data without warning.
Mountain weather information
Weather
Heaviest and persistent raining clearing through the early hours, leaving a largely cloudy day with drizzle on and off. Staying blustery and mild.
Chance of cloud-free hill tops
20% rising to 50% in the east.
Maximum wind speed expected
Southwesterly 40-45 mph.
Temperature
- At 600m Plus 11 Celsius rising to plus 14 Celsius.
- Valley Plus 17 Celsius rising to plus 20 Celsius.
- Freezing level Above summits.
Low cloud and visibility
Similar to Wednesday with widespread low cloud down to 400m. Best of any breaks to the east of the dark during the afternoon. Overall very poor visibility.
Mountain weather information
Fri 19 Sep
Sunrise:
Sunset:
Low confidence in any details on Friday Largely cloudy with outbreaks of rain, turning heavy at times. Moderate southwesterly winds.
Sat 20 Sep
Sunrise:
Sunset:
Further outbreaks of showers or longer spells of rain on Saturday, possibly heavy at times. Moderate southwesterly to westerly winds.
Sun 21 Sep
Sunrise:
Sunset:
Rain expected in the morning, easing off and becoming drier in the afternoon, with brighter spells possible, though low confidence in the detail. Turning colder with moderate to strong northerly winds.
Updated at:
Summit specific forecast
Mountain summit forecast map
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Key
Mountain summits
Other points of interest
Cluster of multiple stations
The Bannau Brycheiniog / Brecon Beacons is a mountain range in South Wales comprising six main peaks, with the highest peak, Pen y Fan, standing at 886 metres.