Coelbren sits near the top of UK towns for rain, with 1,867 mm (74 in) a year
On a normal January night the air cools to about 1.4°C (34°F). Temperatures cover 18°C across the year, low to high. By July afternoons alone, it runs cooler than 82% of UK towns. Gritters and ice scrapers earn their keep on roughly 48 nights a year below 0°C.
Met Office 1991–2020 averages for the town itself.
A year in Coelbren at a glance
Each month’s typical high and low, in °C.
What a year in Coelbren feels like
Typical highs and lows by season and by month, from the Met Office’s 1991–2020 averages.
About 1,867 mm of rain a year
December is the wettest month and April the driest. About 67 days a year bring 10 mm (0.4 in) or more.
Rain by month
Millimetres
48 air frosts and 5 days of 25°C a year
On about 48 nights a year the air drops below freezing, and on about 2 days it stays below freezing all day. About 5 days a year reach 25°C (77°F).
Day counts are 1991–2020 averages from the Met Office’s 2 km grid. The Met Office calls a day of 25°C or more a summer day and a night below 0°C an air frost; ground frosts, on grass, come more often.
The Met Office station at Cardiff Bute Park
Cardiff Bute Park is 29 miles south-east of Coelbren, 9 m (30 ft) above sea level. It is the nearest of the 37 long-running stations the Met Office publishes in full; at that distance read it for sunshine and the station’s own record, not as the town’s figures.
| Month | High | Low | Rain | Air frosts |
|---|---|---|---|---|
| January | 8.6°C | 2.5°C | 127 mm | 8.1 |
| February | 9.1°C | 2.5°C | 93 mm | 7.5 |
| March | 11.3°C | 3.9°C | 85 mm | 3.9 |
| April | 14.4°C | 5.7°C | 72 mm | 1.4 |
| May | 17.4°C | 8.5°C | 78 mm | 0.0 |
| June | 20.1°C | 11.3°C | 73 mm | 0.0 |
| July | 21.8°C | 13.1°C | 84 mm | 0.0 |
| August | 21.4°C | 12.9°C | 105 mm | 0.0 |
| September | 19.1°C | 10.7°C | 87 mm | 0.0 |
| October | 15.2°C | 8.0°C | 128 mm | 1.0 |
| November | 11.6°C | 4.9°C | 131 mm | 3.7 |
| December | 9.1°C | 2.9°C | 140 mm | 8.3 |
| Year | 14.9°C | 7.2°C | 1,201 mm | 34 |
Met Office historic station data, Cardiff Bute Park, 1991–2020 months averaged (a month needs 20 of the 30 years; estimated values counted, missing months left out). Sunshine: Campbell-Stokes recorder.
How Coelbren compares
Against the 2,537 towns and cities of 2,500 or more across the UK, each with its own Met Office averages, and its place among Powys towns that size.
Nearby towns’ climate
The nearest towns of 1,000+ within 12 miles: a hill, a valley or the sea can make a real difference over a few miles.
| Town | July high | January low | Rain a year |
|---|---|---|---|
| Coelbren | 19.6°C | 1.4°C | 1,867 mm |
| Seven Sisters 2.6 mi | 20.2°C 0.6°C warmer | 1.9°C 0.6°C milder | 1,921 mm |
| Glyn-neath 3.5 mi | 20.7°C 1.1°C warmer | 2.4°C 1.1°C milder | 1,605 mm |
| Ystradgynlais 3.7 mi | 20.3°C 0.8°C warmer | 2.2°C 0.8°C milder | 1,923 mm |
| Cwmgwrach 4.0 mi | 20.7°C 1.1°C warmer | 2.4°C 1.1°C milder | 1,605 mm |
| Ystalyfera 5.5 mi | 20.3°C 0.8°C warmer | 2.2°C 0.9°C milder | 1,920 mm |
| Creunant 5.5 mi | 19.8°C about the same | 2.0°C 0.7°C milder | 1,868 mm |
Coelbren weather by month
Average daily high and low, mean temperature and rain, 1991–2020, for the town itself (the Met Office’s HadUK-Grid).
| Month | High | Low | Mean | Rain |
|---|---|---|---|---|
| January | 6.9°C 44°F | 1.4°C 34°F | 4.1°C | 209 mm 8.2 in |
| February | 7.2°C 45°F | 1.2°C 34°F | 4.2°C | 157 mm 6.2 in |
| March | 9.3°C 49°F | 2.4°C 36°F | 5.8°C | 131 mm 5.1 in |
| April | 12.2°C 54°F | 3.9°C 39°F | 8.2°C | 102 mm 4.0 in |
| May | 15.4°C 60°F | 6.7°C 44°F | 11.2°C | 106 mm 4.2 in |
| June | 17.9°C 64°F | 9.5°C 49°F | 13.7°C | 106 mm 4.2 in |
| July | 19.6°C 67°F | 11.4°C 53°F | 15.5°C | 126 mm 5.0 in |
| August | 19.1°C 66°F | 11.3°C 52°F | 15.2°C | 152 mm 6.0 in |
| September | 16.9°C 62°F | 9.2°C 49°F | 13.1°C | 140 mm 5.5 in |
| October | 13.3°C 56°F | 6.8°C 44°F | 10.0°C | 211 mm 8.3 in |
| November | 9.8°C 50°F | 3.9°C 39°F | 6.8°C | 203 mm 8.0 in |
| December | 7.4°C 45°F | 1.9°C 35°F | 4.7°C | 225 mm 8.9 in |
| Year | 12.9°C | 5.8°C | 9.4°C | 1,867 mm |
Where Coelbren’s numbers come from
Averages over 30 years, not a forecast.
- Mean temperature, rain and day counts: HadUK-Grid 1991–2020 averages for the Met Office 2 km grid square nearest Coelbren’s centre (the town is smaller than one square).
- Highs and lows: the Met Office publishes average daily maxima and minima on its 12 km grid; each is moved by the difference between the town’s 2 km mean temperature and the 12 km square’s, which carries the town’s own height and setting over.
- Weather station and sunshine: Met Office historic station data for Cardiff Bute Park, 29 miles away, months of 1991–2020 averaged.
- Comparisons: every town and city of 2,500 or more across the UK, all four nations, read the same way.
Met Office HadUK-Grid · Met Office Climate Data Portal · Historic station data. Open Government Licence v3.0.
Questions about Coelbren’s climate
How warm does Coelbren get in summer?
July is the warmest month, with average highs of 19.6°C (67°F). About 5 days a year reach 25°C (77°F), fewer than 78% of UK towns.
How cold does Coelbren get in winter?
February nights average 1.2°C (34°F). The air drops below freezing on about 48 nights a year, and about 2 days a year stay below freezing all day.
How much rain does Coelbren get?
About 1,867 mm (74 in) a year, more than almost every UK town. December is the wettest month (225 mm) and April the driest (102 mm).
Where do these figures come from?
The Met Office’s HadUK-Grid 1991–2020 averages, which turn thousands of weather stations into a map of the UK in 2 km squares; the page reads the squares inside Coelbren. They are 30-year averages, not a forecast.
Contains Met Office data © Crown copyright 2026, Open Government Licence v3.0. HadUK-Grid 1991–2020 averages via the Met Office Climate Data Portal; station averages from Met Office historic station data. Today’s forecast for Coelbren →
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