Photo: Jaggery · CC BY-SA 2.0Blackwood is among the wettest of UK towns: 1,538 mm (61 in) of rain a year
On a normal July day the thermometer tops out near 20.4°C (69°F). A year here swings 19°C from midwinter lows to midsummer highs. In July, afternoons here are cooler than in 68% of UK towns. Frost greets about 44 mornings a year, so leave time to clear the car.
Met Office 1991–2020 averages for the town itself.
A year in Blackwood at a glance
Each month’s typical high and low, in °C.
What a year in Blackwood feels like
Typical highs and lows by season and by month, from the Met Office’s 1991–2020 averages.
About 1,538 mm of rain a year
December is the wettest month and June the driest. About 49 days a year bring 10 mm (0.4 in) or more. 14th wettest of 38 Gwent towns of 2,500+.
Rain by month
Millimetres
44 air frosts and 7 days of 25°C a year
On about 44 nights a year the air drops below freezing, and on about 2 days it stays below freezing all day. About 7 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 12 miles south of Blackwood, 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 Blackwood 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 |
|---|---|---|---|
| Blackwood | 20.4°C | 1.7°C | 1,538 mm |
| Fleur-de-lis and Pengam 0.8 mi | 20.4°C about the same | 2.0°C about the same | 1,637 mm |
| Pontllanfraith 1.1 mi | 20.7°C about the same | 1.8°C about the same | 1,435 mm |
| Tir-y-berth and Glan-y-nant 1.1 mi | 20.4°C about the same | 1.9°C about the same | 1,525 mm |
| Oakdale 1.4 mi | 20.6°C about the same | 1.5°C about the same | 1,440 mm |
| Pen-pedair-heol 1.7 mi | 20.4°C about the same | 1.9°C about the same | 1,525 mm |
| Ystrad Mynach 1.8 mi | 20.4°C about the same | 2.0°C about the same | 1,637 mm |
Blackwood 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 | 7.1°C 45°F | 1.7°C 35°F | 4.4°C | 162 mm 6.4 in |
| February | 7.4°C 45°F | 1.5°C 35°F | 4.4°C | 133 mm 5.2 in |
| March | 9.6°C 49°F | 2.6°C 37°F | 6.1°C | 110 mm 4.3 in |
| April | 12.8°C 55°F | 4.3°C 40°F | 8.6°C | 91 mm 3.6 in |
| May | 16.0°C 61°F | 7.1°C 45°F | 11.5°C | 91 mm 3.6 in |
| June | 18.7°C 66°F | 10.0°C 50°F | 14.4°C | 86 mm 3.4 in |
| July | 20.4°C 69°F | 11.7°C 53°F | 16.1°C | 100 mm 3.9 in |
| August | 19.9°C 68°F | 11.6°C 53°F | 15.8°C | 112 mm 4.4 in |
| September | 17.5°C 63°F | 9.5°C 49°F | 13.4°C | 116 mm 4.6 in |
| October | 13.6°C 56°F | 7.0°C 45°F | 10.3°C | 177 mm 7.0 in |
| November | 9.9°C 50°F | 4.1°C 39°F | 7.0°C | 171 mm 6.7 in |
| December | 7.5°C 45°F | 2.1°C 36°F | 4.7°C | 191 mm 7.5 in |
| Year | 13.4°C | 6.1°C | 9.7°C | 1,538 mm |
Where Blackwood’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 Blackwood’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, 12 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 Blackwood’s climate
How warm does Blackwood get in summer?
July is the warmest month, with average highs of 20.4°C (69°F). About 7 days a year reach 25°C (77°F), fewer than 66% of UK towns.
How cold does Blackwood get in winter?
February nights average 1.5°C (35°F). The air drops below freezing on about 44 nights a year, and about 2 days a year stay below freezing all day.
How much rain does Blackwood get?
About 1,538 mm (61 in) a year, more than 97% of UK towns. December is the wettest month (191 mm) and June the driest (86 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 Blackwood. 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 Blackwood →
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