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Brecon Beacons - Mountain weather forecast

Weather warnings

Warnings affecting Brecon Beacons over the next 5 days


High for a chilly day, with showers Friday but medium to low for the detail through the weekend, due to uncertainty in the path of weather system which pushes through southern UK. Confidence increasing to medium to high from Monday as high pressure brings more settled conditions

  • Friday
  • Saturday
  • Further outlook

Friday 21 September 2018

Weather hazards

Gales High likelihood Hide detail

Gale force winds (gusts over 50mph) make walking difficult and strenuous with a potential to be blown over by gusts. There is often a marked increase in winds through cols or on exposed ridges and summits. Distances can take longer to cover and compass bearings become harder to follow accurately.

Learn more about gales

Poor visibility Medium likelihood Show detail

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.

Learn more about poor visibility

Thunderstorms Medium likelihood Show detail

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.

Learn more about thunderstorms

Severe chill effect Low likelihood Show detail

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.

Learn more about severe chill effect

Heavy persistent rain Low likelihood Show detail

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.

Learn more about heavy persistent rain


Blustery occasionally heavy showers. Some brighter intervals. Feeling rather cold.


06:00 09:00 12:00 15:00 18:00 21:00
Weather at 600m Light rain Heavy shower day Heavy shower day Light shower day Partly cloudy night Partly cloudy night
Chance of precipitation at 600m 60% 40% 40% 40% 30% 20%

Wind speed and direction

06:00 09:00 12:00 15:00 18:00 21:00
Altitude above mean sea level
600m W 25 32 W 28 36 W 33 46 W 29 41 W 23 32 W 23 32
300m W 14 31 W 17 35 W 21 45 W 18 40 W 12 27 W 11 22
Valley W 13 31 W 16 34 W 19 44 W 17 39 W 11 25 W 11 23


06:00 09:00 12:00 15:00 18:00 21:00
Altitude above mean sea level
600m 5 ° 6 ° 8 ° 9 ° 8 ° 7 °
300m 7 ° 9 ° 11 ° 12 ° 10 ° 9 °
Valley 8 ° 10 ° 12 ° 12 ° 11 ° 10 °

Feels like temperature

06:00 09:00 12:00 15:00 18:00 21:00
Altitude above mean sea level
600m -1 ° 0 ° 2 ° 4 ° 4 ° 3 °
300m 3 ° 5 ° 7 ° 8 ° 8 ° 6 °
Valley 4 ° 6 ° 8 ° 9 ° 9 ° 7 °

Freezing level

06:00 09:00 12:00 15:00 18:00 21:00
Freezing level i 1,200 m 1,200 m 1,400 m 1,500 m 1,500 m 1,400 m
Sunrise: 06:57
Sunset: 19:15
Moon phase: Waxing gibbous


Often cloudy across the hills, however some sunny intervals are likely, especially away from the shrouded summits. Frequent, blustery and occasionally heavy showers are likely, moving quickly through on the strong westerly breeze. These could include the odd burst of hail, along with the risk of lightning. Whilst not quite as windy as on Thursday, winds will remain strong until the evening. Showers will also gradually fade away later in the day.

Chance of cloud-free mountain/hill tops at 600m

70% for much of the day, however cloud often obscuring some summits above 800m. Occasional patches falling as low as 500m during heavy showers. Increasing to 90% into the late afternoon, as cloud clears and showers fade.


: Very good views likely, outside of any showers. However some rapid reductions likely as cloud descends, and showers move through. This likely to bring some transitory poor or very poor visibilities, then improving as showers clear.

Meteorologist's view

A blustery day, and very changeable at height. Outside of showers, conditions are likely to be fine, but windy and feeling noticeably cold. However conditions could turn difficult during showers, as cloud descends, and poor to very poor visibilities develop, along with spells of heavy rain or hail, and the risk of lightning. During heaviest showers isolated gusts could reach up to 20mph more than shown in the table above, especially on exposed ridges.

Recent rainfall

  • Location: Neuadd (Near Pontsticill)
  • Altitude: 353m
  • Measurement date: 03:00 on Fri 21 Sep 2018
  • Last 24 hours: 63.4mm
  • Last 48 hours: 71.4mm
  • Last 72 hours: 80.2mm

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.

Saturday 22 September 2018

Sunrise: 06:59
Sunset: 19:13
Moon phase: Waxing gibbous


Clear spells are likely to develop overnight, and turning cold, especially on the tops. However cloud soon thickens from the southwest during the morning, with rain spreading in by the afternoon. Whilst mostly light, this will turn persistent with the odd heavier burst possible later in the day.

Maximum wind speed expected

Westerly 15mph, gusting 25mph. Becoming Southeasterly 20mph, gusting 25mph from midday.

Chance of cloud-free mountain/hill tops at 600m

Near 100% at first, but soon falling during morning to be 40% by the afternoon with broken cloud at 600m. Best chance of staying clear across the northeast.


  • At 600m Plus 7C
  • Valley Plus 4C rising 15C during the afternoon
  • Freezing level Above the summits


: Some very good views possible at first, but falling to moderate to poor as rain develops during the afternoon

Sunday 23 September 2018

Sunrise: 07:01
Sunset: 19:11
Moon phase: Waxing gibbous

Some significant uncertainty in detail, however further outbreaks of rain likely, especially early in the day, and a risk of very strong winds for a time. Sunshine and blustery showers likely later. Freezing levels above the summits

Monday 24 September 2018

Sunrise: 07:02
Sunset: 19:08
Moon phase: Waxing gibbous

The odd shower remains possible during the morning, however much more benign and settled weather is expected than during the previous week, with winds becoming light. Some autumnal sunshine likely, but also remaining rather cool.

Tuesday 25 September 2018

Sunrise: 07:04
Sunset: 19:06
Moon phase: Full

After a cold start, with some valley frost possible, a dry and largely sunny day is expected. Winds will remain light with freezing levels above the summits.

Issued at:
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The Brecon Beacons is a mountain range in South Wales comprising six main peaks, with the highest peak, Pen y Fan, standing at 886 metres.

The summits of each peak form a long ridge with four of the peaks forming a horseshoe shape around the head of the Taf Fechan River which flows away to the south-east. The Brecon Beacons is said to be named after the ancient practice of lighting signal fires (beacons) on mountains to warn of attacks by invaders, or more recently to commemorate public and national events such as coronations or the Millennium.

For ardent mountain climbers, the Brecon Beacons National Park is among the best that Britain has to offer. While it doesn't have some of the headline-grabbing peaks of Snowdonia or the Scottish Highlands, it fits scores of slightly smaller mountains into its relatively compact 519 square mile area. These include the area's highest peak, Pen y Fan, as well as the marginally smaller Corn Du (873 metres). Both offer rather hospitable, anvil-shaped summits to those who reach the top, with plenty of space for rest and photographs, before tackling the descent.

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