Few UK towns get more rain than Cwm: 1,564 mm (62 in) a year
On a normal July day the thermometer tops out near 19.0°C (66°F). Expect the heaviest rain in January and the lightest in June. By frosts alone, it ranks colder than 94% of UK towns. The heating season runs October to May: each of those months averages under 10°C.
Met Office 1991–2020 averages for the town itself.
A year in Cwm at a glance
Each month’s typical high and low, in °C.
What a year in Cwm feels like
Typical highs and lows by season and by month, from the Met Office’s 1991–2020 averages.
About 1,564 mm of rain a year
January is the wettest month and June the driest. About 59 days a year bring 10 mm (0.4 in) or more. 8th wettest of 38 Gwent towns of 2,500+.
Rain by month
Millimetres
A frosty town: 55 air frosts and 5 days of 25°C a year
On about 55 nights a year the air drops below freezing, and on about 4 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 17 miles south of Cwm, 9 m (30 ft) above sea level. It is the nearest of the 37 long-running stations the Met Office publishes in full.
| 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 Cwm 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 Gwent 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 |
|---|---|---|---|
| Cwm | 19.0°C | 1.0°C | 1,564 mm |
| Blaina 2.1 mi | 19.0°C about the same | 0.8°C about the same | 1,530 mm |
| Abertillery 2.2 mi | 19.1°C about the same | 1.2°C about the same | 1,545 mm |
| Markham 2.6 mi | 19.5°C 0.6°C warmer | 1.3°C about the same | 1,597 mm |
| New Tredegar 2.8 mi | 19.5°C 0.6°C warmer | 0.7°C about the same | 1,734 mm |
| Nantyglo 3.1 mi | 19.0°C about the same | 1.0°C about the same | 1,537 mm |
| Ebbw Vale 3.2 mi | 18.9°C about the same | 1.0°C about the same | 1,705 mm |
Cwm 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 | 6.0°C 43°F | 1.0°C 34°F | 3.5°C | 201 mm 7.9 in |
| February | 6.0°C 43°F | 0.4°C 33°F | 3.2°C | 128 mm 5.0 in |
| March | 8.1°C 47°F | 1.5°C 35°F | 4.8°C | 111 mm 4.4 in |
| April | 11.2°C 52°F | 3.1°C 38°F | 7.1°C | 96 mm 3.8 in |
| May | 14.4°C 58°F | 5.7°C 42°F | 9.9°C | 100 mm 3.9 in |
| June | 17.1°C 63°F | 8.6°C 48°F | 12.8°C | 88 mm 3.4 in |
| July | 19.0°C 66°F | 10.5°C 51°F | 14.8°C | 93 mm 3.7 in |
| August | 18.4°C 65°F | 10.5°C 51°F | 14.5°C | 111 mm 4.4 in |
| September | 16.0°C 61°F | 8.3°C 47°F | 12.2°C | 113 mm 4.4 in |
| October | 12.1°C 54°F | 6.0°C 43°F | 9.0°C | 171 mm 6.7 in |
| November | 8.6°C 48°F | 3.2°C 38°F | 5.9°C | 171 mm 6.7 in |
| December | 6.2°C 43°F | 1.1°C 34°F | 3.6°C | 181 mm 7.1 in |
| Year | 11.9°C | 5.0°C | 8.4°C | 1,564 mm |
Where Cwm’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 Cwm’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, 17 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 Cwm’s climate
How warm does Cwm get in summer?
July is the warmest month, with average highs of 19.0°C (66°F). About 5 days a year reach 25°C (77°F), fewer than 79% of UK towns.
How cold does Cwm get in winter?
February nights average 0.4°C (33°F). The air drops below freezing on about 55 nights a year, and about 4 days a year stay below freezing all day.
How much rain does Cwm get?
About 1,564 mm (62 in) a year, more than 97% of UK towns. January is the wettest month (201 mm) and June the driest (88 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 Cwm. 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 Cwm →
Contains public sector information licensed under the Open Government Licence v3.0. Contains HM Land Registry data © Crown copyright and database right 2026. Contains OS data © Crown copyright and database right 2026 (ONS boundaries). Northern Ireland: Source: NISRA; contains Land & Property Services data and Ordnance Survey of Northern Ireland information, © Crown copyright, licensed under the Open Government Licence v3.0. Scotland: contains National Records of Scotland data, Registers of Scotland data and SEPA data, © Crown copyright / © SEPA 2025, licensed under the Open Government Licence v3.0.