Mountain weather
Bannau Brycheiniog / Brecon Beacons Mountain weather forecast table
Confidence
High for the overall story. Moderate for extent and intensity of showers. Lower for precipitation detail on Wednesday.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
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.
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.
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
Bright spells and well-scattered afternoon showers.
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 600m) |
|
|
|
|
|
|
Chance of precipitation (at 600m) |
<05% | 10% | 20% | 20% | 10% | <05% |
Wind direction and speed (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 600m |
E
12
|
E
10
|
NE
8
|
NE
8
|
NE
6
|
N
5
|
| 300m |
NE
6
|
E
7
|
E
6
|
NE
6
|
NE
3
|
NW
4
|
| Valley |
E
5
|
E
6
|
E
6
|
N
4
|
N
3
|
NW
4
|
Wind gust (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 600m | 17 | 14 | 12 | 12 | 9 | 8 |
| 300m | 11 | 12 | 11 | 11 | 7 | 7 |
| Valley | 10 | 11 | 11 | 9 | 7 | 7 |
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 600m |
6°
|
9°
|
11°
|
13°
|
13°
|
10°
|
| 300m |
8°
|
12°
|
15°
|
15°
|
15°
|
10°
|
| Valley |
9°
|
13°
|
16°
|
16°
|
16°
|
11°
|
| Freezing Level |
1,700m
|
1,600m
|
1,800m
|
1,800m
|
1,800m
|
1,800m
|
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 600m |
3°
|
6°
|
9°
|
11°
|
11°
|
9°
|
| 300m |
6°
|
10°
|
13°
|
14°
|
14°
|
10°
|
| Valley |
8°
|
12°
|
15°
|
15°
|
15°
|
10°
|
Additional weather information
Meteorologist's view
High UV forecast so sun protection advised during the day in sunny spells. Sharp showers may lead to a sudden deterioration in otherwise fine walking conditions including thunderstorms and slippery surfaces.
Weather
Patchy cloud across eastern slopes clearing to leave bright or sunny spells. Cloud bubbling up by late-morning with well-scattered showers likely during the afternoon, with the chance that these are locally heavy or thundery. Showers easing during the evening and skies largely clearing overnight.
Chance of cloud-free hill tops
70% in the east during the early hours, otherwise around 90%
Low cloud and visibility
Areas of low cloud in the east of the park initially, with bases around 500m. Cloud soon lifting and breaking to be above summits. In the vicinity of showers, cloud may briefly obscure higher tops or routes. Visibility generally very good or excellent outside of cloud, but temporarily dropping to moderate or poor as showers pass through.
Recent rainfall
Location: Neuadd (Near Pontsticill)
Altitude: 353m
| Last 24 hours | Last 48 hours | Last 72 hours |
|---|---|---|
| 0mm | 0mm | 0mm |
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
Any early mist and fog patches soon clearing. A widely fine and bright morning with plenty of sunshine. Cloud building through the afternoon with scattered showers again developing, these turning heavy and possibly thundery at times. Cloud spilling eastwards during the evening, thickening to give a risk of rain by midnight.
Chance of cloud-free hill tops
90% or higher
Maximum wind speed expected
Northeast 10-15 mph turning northwest 10-15 mph and gusting 20-25 mph by evening.
Temperature
- At 600m Plus 8 Celsius, rising to plus 14 Celsius.
- Valley Plus 7 Celsius, rising to plus 19 Celsius.
- Freezing level Above the summits.
Low cloud and visibility
Cloud likely remaining above summits, although patches may briefly shroud tops in the vicinity of showers. Generally very good visibility, but poor or very poor in early mist or fog, and moderate or poor near showers.
Mountain weather information
Wed 21 May
Sunrise:
Sunset:
Cloudy and unsettled morning as an area of locally heavy rain or showers runs eastward across southern Wales and southwest England. This is expected to clear to warm sunny spells and isolated showers. Moderate to fresh northwest winds. Moderate confidence in details. Freezing level above tops.
Thu 22 May
Sunrise:
Sunset:
A narrow band of cloud is expected to pass over the park during the morning, clearing to long spells of sunshine. Fair weather cloud bubbling up during the afternoon but likely to remain dry. Gentle north to northwest breeze, becoming blustery during the afternoon. Freezing level remaining above summits.
Fri 23 May
Sunrise:
Sunset:
Most likely a fine and dry day with variable cloud and warm sunny spells. Afternoon sunshine turning increasingly hazy as cloud thickens from the west. Gentle northwest winds, turning southwest by the afternoon. Rain likely to arrive overnight. Moderate confidence in details. Freezing level well above tops.
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.