Mountain weather
Bannau Brycheiniog / Brecon Beacons Mountain weather forecast table
Confidence
High overall, though moderate for location and intensity of heavy and thundery showers.
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.
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.
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.
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.
Mountain weather forecast
Sunny spells and heavy, thundery showers.
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
Weather (at 600m) |
|
|
|
|
|
|
Chance of precipitation (at 600m) |
<05% | 10% | 30% | 60% | 70% | 70 |
Wind direction and speed (mph)
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 600m |
E
6
|
NE
8
|
E
6
|
E
6
|
W
6
|
W
6
|
| 300m |
E
2
|
NE
5
|
E
5
|
E
4
|
W
5
|
SW
4
|
| Valley |
N
1
|
E
4
|
E
4
|
S
4
|
W
5
|
W
4
|
Wind gust (mph)
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 600m | 8 | 11 | 10 | 10 | 10 | 8 |
| 300m | 4 | 9 | 10 | 9 | 10 | 8 |
| Valley | 3 | 8 | 9 | 9 | 12 | 9 |
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 600m |
9°
|
11°
|
14°
|
12°
|
11°
|
10°
|
| 300m |
10°
|
15°
|
16°
|
14°
|
12°
|
12°
|
| Valley |
10°
|
15°
|
17°
|
14°
|
13°
|
12°
|
| Freezing Level |
1,900m
|
1,900m
|
2,100m
|
2,200m
|
2,300m
|
2,300m
|
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 600m |
8°
|
10°
|
12°
|
11°
|
9°
|
8°
|
| 300m |
10°
|
14°
|
15°
|
14°
|
12°
|
11°
|
| Valley |
10°
|
15°
|
16°
|
13°
|
12°
|
11°
|
Additional weather information
Meteorologist's view
Bright sunshine at first, sun cream advised, but waterproofs recommended in the afternoon. Some swollen watercourses.
Weather
Any mist and shallow fog patches will soon clear to give a dry and sunny morning. Some showers will then move in from the east and north around midday, turning heavy with a risk of hail and thunder in the afternoon. Showers persisting into the evening.
Chance of cloud-free hill tops
80% during the early hours but generally 95% or more by mid-morning. Reduced to 60-80% in the afternoon.
Low cloud and visibility
Some mist and shallow fog patches initially but soon clearing. Bases generally above summits by day, lowering from late afternoon associated with rainfall to 600-700m. Good visibility with clear views of distant hills, moderate in rain or showers, poor in cloud at elevation later.
Recent rainfall
Location: Neuadd (Near Pontsticill)
Altitude: 353m
| Last 24 hours | Last 48 hours | Last 72 hours |
|---|---|---|
| 1.6mm | 35.8mm | 35.8mm |
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
Low cloud and drizzle possible during the early hours. This clearing to sunshine and showers during the morning, some heavy and potentially thundery once more.
Chance of cloud-free hill tops
40% during the early hours, then 90% from mid-morning onwards.
Maximum wind speed expected
Northwesterly 10mph gusting 15-20mph, perhaps 30-40mph in any thunderstorms.
Temperature
- At 600m Plus 8 Celsius rising to plus 12 Celsius.
- Valley Plus 12 Celsius rising to plus 20 Celsius.
- Freezing level Above the summits.
Low cloud and visibility
Bases between 400-600m in the early hours, clearing by mid-morning with cloud bases largely above the summits and excellent visibility prevailing. During heavy showers cloud bases may fall to 600m for a time and the visibility will be reduced to poor or very.
Mountain weather information
Sat 18 May
Sunrise:
Sunset:
Low cloud and light rain initially, then brightening up with sunny spells and scattered heavy showers. Light to moderate northerly winds.
Sun 19 May
Sunrise:
Sunset:
Morning fog patches soon clearing then a largely dry day with lengthy sunny periods. Light northeasterly winds.
Mon 20 May
Sunrise:
Sunset:
Morning mist and fog quickly clearing, then dry with sunny spells. Light easterly 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.