Mountain weather
Bannau Brycheiniog / Brecon Beacons Mountain weather forecast table
Confidence
High for the changeable conditions this week, lower for day to day details.
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.
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.
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
A few bright or sunny intervals but often cloudy, with occasional showers which will be wintry on the highest hills, and with a small chance of lightning.
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 600m) |
|
|
|
|
|
|
Chance of precipitation (at 600m) |
30% | 30% | 50% | 60% | 60% | 40% |
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
16
|
SW
15
|
SW
16
|
S
14
|
S
13
|
SW
12
|
| 300m |
SW
9
|
SW
8
|
SW
10
|
S
6
|
SW
6
|
SW
7
|
| Valley |
SW
9
|
SW
7
|
SW
8
|
S
4
|
SW
4
|
SW
5
|
Wind gust (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 600m | 22 | 20 | 21 | 18 | 17 | 16 |
| 300m | 21 | 18 | 20 | 13 | 13 | 15 |
| Valley | 22 | 18 | 18 | 12 | 11 | 14 |
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 600m |
4°
|
3°
|
4°
|
4°
|
3°
|
3°
|
| 300m |
5°
|
5°
|
6°
|
6°
|
4°
|
4°
|
| Valley |
6°
|
6°
|
7°
|
7°
|
5°
|
5°
|
| Freezing Level |
1,100m
|
1,000m
|
1,100m
|
1,100m
|
1,000m
|
1,000m
|
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 600m |
-2°
|
-2°
|
-1°
|
-1°
|
-2°
|
-2°
|
| 300m |
2°
|
2°
|
4°
|
4°
|
2°
|
2°
|
| Valley |
3°
|
3°
|
5°
|
6°
|
4°
|
3°
|
Additional weather information
Meteorologist's view
Poor underfoot conditions due to the recent very wet weather with some fast flowing water courses especially at first, and some flooding in car parks and access roads
Weather
Bright or sunny intervals and a few showers in the morning then cloudier in the afternoon with more frequent showers, some heavy with the chance of thunder, and perhaps some sleet or wet snow above 800m.
Chance of cloud-free hill tops
60% in morning falling 30% in afternoon.
Low cloud and visibility
Broken or occasional cloud at 600-700m in morning becoming more extensive in afternoon with the odd patch to 450m especially in the south. Visibility occasionally good away from cloud and showers, but falling moderate to poor in the showers, and very poor in hill fog above the cloud line and in wet snow.
Recent rainfall
Location: Neuadd (Near Pontsticill)
Altitude: 353m
| Last 24 hours | Last 48 hours | Last 72 hours |
|---|---|---|
| 37.6mm | 43.4mm | 62.6mm |
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
Clear or sunny intervals and occasional showers, wintry on summits in early hours, with perhaps more extensive cloud in the morning. More persistent rain arriving later in the evening.
Chance of cloud-free hill tops
20% rising 50% in afternoon
Maximum wind speed expected
South-westerly 20 gusts 30mph.
Temperature
- At 600m Plus 2 rising to Plus 4 Celsius
- Valley Plus 5 rising to Plus 9 Celsius
- Freezing level 900m rising above summits before morning
Low cloud and visibility
Broken to overcast cloud in morning bases 500-700m with the odd lower patch, becoming more broken in the afternoon with bases rising to nearer 700-800m, still a few lower patches though. Visibility below the cloud, often good but moderate briefly poor as showers pass through.
Mountain weather information
Thu 4 Dec
Sunrise:
Sunset:
Mainly cloudy with frequent showers, falling as snow above 600-700m. Moderate to fresh south-westerly winds.
Fri 5 Dec
Sunrise:
Sunset:
A dry morning with sunny spells and patchy valley fog. Becoming cloudier in afternoon then rain and strong winds in the evening. Low confidence.
Sat 6 Dec
Sunrise:
Sunset:
Confidence remains low, but most likely a showery day with strong to gale force westerly 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.