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Climate in Blaenavon · Met Office 1991–2020 averages

Blaenavon sits near the bottom of UK towns for winter warmth

The warmest part of a July day comes in at 20.0°C (68°F) on average. The gap between a January night and a July afternoon is 20°C. By rainfall alone, it ranks wetter than 96% of UK towns. Garden chairs stay out from June to September, the months with highs of 17–20°C.

July afternoons: cooler than 75% of UK towns
January nights: colder than 98% of UK towns
Rain a year: wetter than 96% of UK towns

Met Office 1991–2020 averages for the town itself.

A year in Blaenavon at a glance

Each month’s typical high and low, in °C.

Jan6°C1°CFrosty nights
Feb7°C1°CColdest nights
Mar9°C2°C
Apr12°C3°C
May15°C6°C
Jun18°C8°C
Jul20°C10°CWarmest
Aug20°C10°C
Sep17°C8°C
Oct13°C6°C
Nov now9°C3°C
Dec7°C1°CWettest
A normal year

What a year in Blaenavon feels like

Typical highs and lows by season and by month, from the Met Office’s 1991–2020 averages.

Winter
7°C / 1°C
44°F / 33°F · 486 mm of rain, the wettest season
Spring
12°C / 3°C
54°F / 38°F · 302 mm of rain
Summer
19°C / 10°C
67°F / 49°F · 4 days of 25°C+ a year
Autumn
13°C / 6°C
56°F / 42°F · 455 mm of rain
Best months to be outsideJunJulAugSepHighs of 17–27°C (63–81°F) and nights of 8°C (46°F) or more
Rain

About 1,518 mm of rain a year

December is the wettest month and June the driest. About 52 days a year bring 10 mm (0.4 in) or more. 20th wettest of 38 Gwent towns of 2,500+.

1,518 mm
Rain a year (60 in)
Wetter than 96% of UK towns
52
Days a year with 10 mm of rain or more

Rain by month

Millimetres

182 mm
JFMAMJJASOND
Frost & warm days

A frosty town: 59 air frosts and 4 days of 25°C a year

On about 59 nights a year the air drops below freezing, and on about 5 days it stays below freezing all day. About 4 days a year reach 25°C (77°F).

59
Air frosts a year (below 0°C)
More frosts than 96% of UK towns
5
Days that stay below 0°C
4
Days of 25°C (77°F) or more
Fewer warm days than 80% of UK towns

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.

Weather station

The Met Office station at Cardiff Bute Park

Cardiff Bute Park is 20 miles south of Blaenavon, 9 m (30 ft) above sea level. It is the nearest of the 37 long-running stations the Met Office publishes in full.

MonthHighLowRainAir frosts
January8.6°C2.5°C127 mm8.1
February9.1°C2.5°C93 mm7.5
March11.3°C3.9°C85 mm3.9
April14.4°C5.7°C72 mm1.4
May17.4°C8.5°C78 mm0.0
June20.1°C11.3°C73 mm0.0
July21.8°C13.1°C84 mm0.0
August21.4°C12.9°C105 mm0.0
September19.1°C10.7°C87 mm0.0
October15.2°C8.0°C128 mm1.0
November11.6°C4.9°C131 mm3.7
December9.1°C2.9°C140 mm8.3
Year14.9°C7.2°C1,201 mm34

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.

Compared with other towns

How Blaenavon 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.

July afternoons20.0°C (68°F)
Cooler than 75% of UK towns28th warmest of 38 Gwent towns
January nights0.6°C (33°F)
Colder than 98% of UK towns38th mildest of 38 Gwent towns
Rain a year1,518 mm (60 in)
Wetter than 96% of UK towns20th wettest of 38 Gwent towns
Air frosts a year59 nights
More frosts than 96% of UK towns2nd frostiest of 38 Gwent towns
Days of 25°C or more4 days
Fewer warm days than 80% of UK towns36th most 25°C days of 38 Gwent towns
Next door

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.

TownJuly highJanuary lowRain a year
Blaenavon20.0°C0.6°C1,518 mm
Abersychan 3.0 mi20.0°C about the same1.2°C 0.6°C milder1,500 mm
Govilon 3.2 mi21.2°C 1.2°C warmer2.4°C 1.8°C milder940 mm
Blaina 3.2 mi19.0°C 1.1°C cooler0.8°C about the same1,530 mm
Abertillery 3.6 mi19.1°C 0.9°C cooler1.2°C 0.7°C milder1,545 mm
Llanfoist 3.6 mi21.2°C 1.2°C warmer2.6°C 2.0°C milder944 mm
Gilwern 3.7 mi21.2°C 1.2°C warmer2.1°C 1.5°C milder961 mm
Month by month

Blaenavon weather by month

Average daily high and low, mean temperature and rain, 1991–2020, for the town itself (the Met Office’s HadUK-Grid).

MonthHighLowMeanRain
January6.3°C 43°F0.6°C 33°F3.4°C174 mm 6.9 in
February6.9°C 44°F0.5°C 33°F3.7°C129 mm 5.1 in
March9.2°C 49°F1.5°C 35°F5.3°C110 mm 4.3 in
April12.2°C 54°F3.1°C 38°F7.6°C94 mm 3.7 in
May15.3°C 59°F5.6°C 42°F10.3°C97 mm 3.8 in
June18.1°C 65°F8.4°C 47°F13.2°C85 mm 3.4 in
July20.0°C 68°F10.4°C 51°F15.2°C87 mm 3.4 in
August19.6°C 67°F10.1°C 50°F14.9°C104 mm 4.1 in
September17.1°C 63°F8.0°C 46°F12.6°C106 mm 4.2 in
October13.2°C 56°F5.7°C 42°F9.4°C176 mm 6.9 in
November9.5°C 49°F3.0°C 37°F6.2°C173 mm 6.8 in
December6.9°C 44°F1.1°C 34°F4.0°C182 mm 7.2 in
Year12.9°C4.8°C8.8°C1,518 mm
Sources

Where Blaenavon’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 Blaenavon’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, 20 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 Blaenavon’s climate

How warm does Blaenavon get in summer?

July is the warmest month, with average highs of 20.0°C (68°F). About 4 days a year reach 25°C (77°F), fewer than 80% of UK towns.

How cold does Blaenavon get in winter?

February nights average 0.5°C (33°F). The air drops below freezing on about 59 nights a year, and about 5 days a year stay below freezing all day.

How much rain does Blaenavon get?

About 1,518 mm (60 in) a year, more than 96% of UK towns. December is the wettest month (182 mm) and June the driest (85 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 Blaenavon. 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 Blaenavon →

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.