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.
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
Misty low cloud clearing then warm sunny spells and isolated heavy showers.
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
Weather (at 600m) |
|
|
|
|
|
|
Chance of precipitation (at 600m) |
<05% | 00% | 30% | 40% | 30% | 10% |
Wind direction and speed (mph)
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 600m |
S
6
|
S
5
|
S
6
|
SW
4
|
NW
6
|
NW
5
|
| 300m |
E
2
|
E
3
|
E
4
|
W
5
|
NW
5
|
W
4
|
| Valley |
NE
2
|
E
3
|
E
4
|
NW
4
|
NW
4
|
W
4
|
Wind gust (mph)
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 600m | 8 | 8 | 10 | 7 | 9 | 8 |
| 300m | 4 | 6 | 8 | 8 | 9 | 6 |
| Valley | 3 | 6 | 8 | 9 | 10 | 6 |
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 600m |
9°
|
12°
|
14°
|
15°
|
14°
|
11°
|
| 300m |
10°
|
14°
|
16°
|
18°
|
16°
|
12°
|
| Valley |
11°
|
15°
|
17°
|
18°
|
17°
|
12°
|
| Freezing Level |
2,000m
|
2,000m
|
2,100m
|
2,200m
|
2,200m
|
2,200m
|
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 600m |
7°
|
11°
|
13°
|
14°
|
13°
|
10°
|
| 300m |
10°
|
14°
|
16°
|
17°
|
16°
|
11°
|
| Valley |
11°
|
15°
|
17°
|
18°
|
16°
|
12°
|
Additional weather information
Meteorologist's view
Strong sunshine at this time of the year so ensure you have sun protection with high UV levels expected.
Weather
Any mist, fog and patchy low cloud should readily clear, followed by sunny spells but a few isolated showers developing in the morning. A warm afternoon with sunny spells but isolated slow-moving showers, some of which heavy and perhaps thundery. Becoming dry during the evening.
Chance of cloud-free hill tops
80% soon rising to 95% or more by mid-morning.
Low cloud and visibility
Some mist and fog in prone valleys steadily clearing by mid-morning. Some patches of low cloud around 200-300m, lifting and clearing most summits by mid-morning. Generally good visibility thereafter but deteriorating to mediocre in any afternoon showers, with a low risk of poor or very poor in any heavy showers or thunderstorms.
Recent rainfall
Location: Neuadd (Near Pontsticill)
Altitude: 353m
| Last 24 hours | Last 48 hours | Last 72 hours |
|---|---|---|
| 5mm | 5mm | 6.6mm |
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
Any low cloud at first, soon clearing to once again leave a day of sunny spells and showers. Perhaps fewer sunny intervals than on Friday with a higher risk of heavy showers. These could be slow-moving and locally thundery with hail possible before easing through the evening.
Chance of cloud-free hill tops
60% becoming 90% by mid-morning. Falling to 60% during showers.
Maximum wind speed expected
Northerly 10-15 mph.
Temperature
- At 600m Plus 10 Celsius rising to plus 15 Celsius.
- Valley Plus 9 Celsius rising to plus 20 Celsius.
- Freezing level Well above the summits.
Low cloud and visibility
Areas of low cloud above 500m at first and some mist or fog also possible in the valleys. Cloud and fog lifting and clearing most summits by mid-morning. Generally good visibility thereafter but deteriorating to poor or very poor in any afternoon heavy showers or thunderstorms.
Mountain weather information
Sun 19 May
Sunrise:
Sunset:
Morning fog patches soon clearing then a largely dry day with lengthy sunny periods. The small chance of an isolated afternoon shower developing. Light northeasterly winds. High UV levels.
Mon 20 May
Sunrise:
Sunset:
Morning mist and fog quickly clearing, then dry with sunny spells. Light northeasterly winds. High UV levels.
Tue 21 May
Sunrise:
Sunset:
Turning more changeable but some uncertainty in the details. Showers developing with a chance of longer spells of rain later. Winds remaining light from variable directions.
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.