Llanhilleth is among the wettest of UK towns: 1,538 mm (61 in) of rain a year
In January the night’s low is typically 1.3°C (34°F). In July, afternoons here are cooler than in 88% of UK towns. Only 19°C separates winter nights from summer afternoons. Radiators earn their keep from October to April, the months that average under 10°C.
Met Office 1991–2020 averages for the town itself.
A year in Llanhilleth at a glance
Each month’s typical high and low, in °C.
What a year in Llanhilleth 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.
Rain by month
Millimetres
A frosty town: 50 air frosts and 6 days of 25°C a year
On about 50 nights a year the air drops below freezing, and on about 2 days it stays below freezing all day. About 6 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 15 miles south of Llanhilleth, 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 Llanhilleth 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 |
|---|---|---|---|
| Llanhilleth | 19.2°C | 1.3°C | 1,538 mm |
| Trinant 0.6 mi | 19.5°C about the same | 1.5°C about the same | 1,577 mm |
| Swffryd 1.4 mi | 19.9°C 0.7°C warmer | 1.0°C about the same | 1,616 mm |
| Abertillery 2.0 mi | 19.1°C about the same | 1.2°C about the same | 1,545 mm |
| Newbridge 2.3 mi | 20.6°C 1.4°C warmer | 1.7°C about the same | 1,438 mm |
| Oakdale 2.4 mi | 20.6°C 1.4°C warmer | 1.5°C about the same | 1,440 mm |
| Markham 3.0 mi | 19.5°C about the same | 1.3°C about the same | 1,597 mm |
Llanhilleth 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 | 6.7°C 44°F | 1.3°C 34°F | 4.0°C | 167 mm 6.6 in |
| February | 6.3°C 43°F | 0.4°C 33°F | 3.3°C | 127 mm 5.0 in |
| March | 8.5°C 47°F | 1.4°C 35°F | 5.0°C | 107 mm 4.2 in |
| April | 11.5°C 53°F | 3.0°C 37°F | 7.3°C | 95 mm 3.8 in |
| May | 14.6°C 58°F | 5.6°C 42°F | 10.1°C | 99 mm 3.9 in |
| June | 17.3°C 63°F | 8.6°C 48°F | 13.0°C | 88 mm 3.5 in |
| July | 19.2°C 67°F | 10.6°C 51°F | 14.9°C | 96 mm 3.8 in |
| August | 18.7°C 66°F | 10.5°C 51°F | 14.6°C | 115 mm 4.5 in |
| September | 16.4°C 61°F | 8.4°C 47°F | 12.3°C | 116 mm 4.6 in |
| October | 12.4°C 54°F | 5.8°C 43°F | 9.1°C | 174 mm 6.9 in |
| November | 8.9°C 48°F | 3.1°C 38°F | 6.0°C | 169 mm 6.7 in |
| December | 6.5°C 44°F | 1.1°C 34°F | 3.7°C | 184 mm 7.2 in |
| Year | 12.2°C | 5.0°C | 8.6°C | 1,538 mm |
Where Llanhilleth’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 Llanhilleth’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, 15 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 Llanhilleth’s climate
How warm does Llanhilleth get in summer?
July is the warmest month, with average highs of 19.2°C (67°F). About 6 days a year reach 25°C (77°F), fewer than 71% of UK towns.
How cold does Llanhilleth get in winter?
February nights average 0.4°C (33°F). The air drops below freezing on about 50 nights a year, and about 2 days a year stay below freezing all day.
How much rain does Llanhilleth get?
About 1,538 mm (61 in) a year, more than 97% of UK towns. December is the wettest month (184 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 Llanhilleth. 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 Llanhilleth →
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