Mountain weather
Bannau Brycheiniog / Brecon Beacons Mountain weather forecast table
Confidence
High overall though moderate in northern extent of persistent rainfall through Tuesday morning. Lower for details around low pressure systems arriving later in the week.
This evening forecast
Scattered showers, sometimes heavy, interspersed with some dry, clear spells.
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
A band of rain moves eastwards through the morning, followed by blustery, sometimes heavy and thundery showers in the afternoon.
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
Weather (at 600m) |
|
|
|
|
|
|
|
|
Chance of precipitation (at 600m) |
80% | 80% | 80% | >95% | >95% | 70% | 60% | 40% |
Wind direction and speed (mph)
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 600m |
SW
15
|
S
15
|
S
16
|
SE
15
|
SE
12
|
SE
7
|
W
7
|
SW
10
|
| 300m |
SW
8
|
SW
8
|
S
6
|
SE
7
|
SE
6
|
E
6
|
SW
4
|
SW
6
|
| Valley |
SW
7
|
SW
4
|
SE
4
|
E
6
|
E
6
|
SE
5
|
SW
4
|
W
6
|
Wind gust (mph)
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 600m | 21 | 20 | 20 | 20 | 16 | 11 | 10 | 14 |
| 300m | 18 | 19 | 16 | 15 | 12 | 10 | 8 | 14 |
| Valley | 18 | 15 | 13 | 13 | 11 | 9 | 9 | 14 |
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 600m |
10°
|
10°
|
10°
|
11°
|
12°
|
13°
|
13°
|
11°
|
| 300m |
12°
|
12°
|
12°
|
13°
|
15°
|
16°
|
15°
|
13°
|
| Valley |
12°
|
12°
|
12°
|
13°
|
15°
|
16°
|
16°
|
14°
|
| Freezing Level |
2,000m
|
2,100m
|
2,100m
|
2,500m
|
2,600m
|
2,600m
|
2,500m
|
2,300m
|
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 600m |
7°
|
7°
|
7°
|
8°
|
10°
|
12°
|
12°
|
10°
|
| 300m |
10°
|
10°
|
10°
|
12°
|
14°
|
15°
|
15°
|
12°
|
| Valley |
11°
|
11°
|
12°
|
13°
|
14°
|
16°
|
16°
|
13°
|
Additional weather information
Meteorologist's view
A wet and windy day, waterproofs are essential, especially if planning to walk in the morning. Whilst they are likely to be infrequent, be prepared to take shelter if thunderstorms develop. Sun protection recommended if walking in the afternoon, as UV levels will rise during any sunny spells.
Weather
Some early clear spells will soon be replaced by cloud thickening from the southwest, with a band of rain moving across the area through the morning. Some heavy downpours are possible, especially over the highest mountains, bringing the risk of thunder. Turning brighter into the afternoon with rain turning more showery, with dry spells becoming more prolonged into the evening.
Chance of cloud-free hill tops
20% becoming 60% in the afternoon.
Low cloud and visibility
Some clear spells at first, but cloud will soon become widespread with bases between 300-500m, obscuring the summits. Very poor visibility in extensive hill fog and persistent rain through the morning, but improving by the afternoon. Cloud bases lifting to mostly above the summits with visibility becoming very good in dry periods, however sudden, sharp deteriorations in cloud bases and visibility are likely during showers into the afternoon.
Recent rainfall
Location: Neuadd (Near Pontsticill)
Altitude: 353m
| Last 24 hours | Last 48 hours | Last 72 hours |
|---|---|---|
| 12.4mm | 15.2mm | 25.7mm |
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
Widely wet and windy through the morning with cloud and rain spreading in from the southwest. Remaining blustery into the afternoon, with frequent heavy showers developing, with the occasional rumble of thunder possible at times too, however a few sunny spells will also develop.
Chance of cloud-free hill tops
10% through the morning, becoming 60% through the afternoon.
Maximum wind speed expected
Southwesterly 40-45 mph.
Temperature
- At 600m Plus 9 Celsius increasing to 13 Celsius.
- Valley Plus 12 Celsius increasing to 19 Celsius.
- Freezing level Above the summits.
Low cloud and visibility
Widespread low cloud will cover the summits above 400m through the morning, with very poor visibility in prolonged and sometimes heavy spells of rain. Brighter later with cloud mostly lifting to above the summits. Very good visibility in drier periods, with excellent air quality allowing for far reaching views of distant peaks, however sharp, sudden deteriorations are expected during showers.
Mountain weather information
Thu 4 Sep
Sunrise:
Sunset:
A mixture of sunshine and scattered showers, these sometimes heavy, but less frequent than previous days. Feeling warm in sunny, sheltered spots, but still rather breezy in showers.
Fri 5 Sep
Sunrise:
Sunset:
Cloudy at first, but dry with sunny spells expected to develop throughout the day. The odd light shower can't be ruled out, but most places remaining dry with moderate to fresh southwesterly winds.
Sat 6 Sep
Sunrise:
Sunset:
Another more settled day, with spells of warm sunshine in sheltered spots. Mostly dry, but skies likely turning hazy into the afternoon as cloud approaches from the west. A few spots of rain arriving later.
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.