Wet weather: 961 mm (38 in) a year falls on Gilwern, more than on 75% of UK towns
High summer brings afternoon highs near 21.2°C (70°F). Winters are mild: January nights here are milder than in 71% of UK towns. Expect the heaviest rain in January and the lightest in July. Gritters and ice scrapers earn their keep on roughly 43 nights a year below 0°C.
Met Office 1991–2020 averages for the town itself.
A year in Gilwern at a glance
Each month’s typical high and low, in °C.
What a year in Gilwern feels like
Typical highs and lows by season and by month, from the Met Office’s 1991–2020 averages.
About 961 mm of rain a year
January is the wettest month and July the driest. About 39 days a year bring 10 mm (0.4 in) or more.
Rain by month
Millimetres
Sunshine by month
Hours of bright sunshine at Ross-on-Wye
43 air frosts and 10 days of 25°C a year
On about 43 nights a year the air drops below freezing, and on about 1 days it stays below freezing all day. About 10 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 Ross-on-Wye
Ross-on-Wye is 23 miles east of Gilwern, 67 m (220 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 | Sun (hours) |
|---|---|---|---|---|---|
| January | 8.0°C | 2.2°C | 76 mm | 9.0 | 55 |
| February | 8.7°C | 2.1°C | 55 mm | 8.4 | 77 |
| March | 11.2°C | 3.3°C | 53 mm | 4.9 | 118 |
| April | 14.2°C | 5.0°C | 55 mm | 2.0 | 165 |
| May | 17.4°C | 7.8°C | 57 mm | 0.1 | 202 |
| June | 20.3°C | 10.7°C | 56 mm | 0.0 | 201 |
| July | 22.3°C | 12.6°C | 52 mm | 0.0 | 209 |
| August | 21.7°C | 12.5°C | 64 mm | 0.0 | 188 |
| September | 19.1°C | 10.3°C | 57 mm | 0.0 | 143 |
| October | 14.8°C | 7.7°C | 85 mm | 1.2 | 104 |
| November | 10.9°C | 4.6°C | 80 mm | 4.5 | 63 |
| December | 8.3°C | 2.4°C | 79 mm | 8.8 | 47 |
| Year | 14.7°C | 6.8°C | 768 mm | 39 | 1,570 |
Met Office historic station data, Ross-On-Wye, 1991–2020 months averaged (a month needs 20 of the 30 years; estimated values counted, missing months left out). Sunshine: Kipp & Zonen recorder.
How Gilwern 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 |
|---|---|---|---|
| Gilwern | 21.2°C | 2.1°C | 961 mm |
| Govilon 1.3 mi | 21.2°C about the same | 2.4°C about the same | 940 mm |
| Llanfoist 2.8 mi | 21.2°C about the same | 2.6°C 0.5°C milder | 944 mm |
| Crickhowell 3.1 mi | 21.4°C about the same | 2.5°C about the same | 1,203 mm |
| Abergavenny 3.2 mi | 21.2°C about the same | 2.3°C about the same | 1,110 mm |
| Blaenavon 3.7 mi | 20.0°C 1.2°C cooler | 0.6°C 1.5°C colder | 1,518 mm |
| Brynmawr 4.1 mi | 19.4°C 1.9°C cooler | 1.1°C 1.0°C colder | 1,522 mm |
Gilwern 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 | 7.8°C 46°F | 2.1°C 36°F | 4.9°C | 142 mm 5.6 in |
| February | 8.2°C 47°F | 1.8°C 35°F | 5.0°C | 76 mm 3.0 in |
| March | 10.5°C 51°F | 2.8°C 37°F | 6.6°C | 66 mm 2.6 in |
| April | 13.5°C 56°F | 4.4°C 40°F | 8.9°C | 64 mm 2.5 in |
| May | 16.6°C 62°F | 6.9°C 44°F | 11.7°C | 53 mm 2.1 in |
| June | 19.4°C 67°F | 9.7°C 49°F | 14.5°C | 57 mm 2.2 in |
| July | 21.2°C 70°F | 11.6°C 53°F | 16.4°C | 48 mm 1.9 in |
| August | 20.6°C 69°F | 11.2°C 52°F | 16.0°C | 66 mm 2.6 in |
| September | 18.0°C 64°F | 8.9°C 48°F | 13.5°C | 69 mm 2.7 in |
| October | 14.2°C 58°F | 6.7°C 44°F | 10.4°C | 107 mm 4.2 in |
| November | 10.6°C 51°F | 4.1°C 39°F | 7.4°C | 108 mm 4.3 in |
| December | 8.0°C 46°F | 2.1°C 36°F | 5.0°C | 106 mm 4.2 in |
| Year | 14.1°C | 6.0°C | 10.0°C | 961 mm |
Where Gilwern’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 Gilwern’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 Ross-On-Wye, 23 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 Gilwern’s climate
How warm does Gilwern get in summer?
July is the warmest month, with average highs of 21.2°C (70°F). About 10 days a year reach 25°C (77°F), fewer than 51% of UK towns.
How cold does Gilwern get in winter?
February nights average 1.8°C (35°F). The air drops below freezing on about 43 nights a year, and about 1 days a year stay below freezing all day.
How much rain does Gilwern get?
About 961 mm (38 in) a year, more than 75% of UK towns. January is the wettest month (142 mm) and July the driest (48 mm).
How sunny is it?
The nearest Met Office station with a sunshine record, Ross-on-Wye (23 miles away), averages 1,570 hours of bright sunshine a year. Sunshine isn’t on the town grid, so this is the station’s figure.
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 Gilwern. 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 Gilwern →
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.