Cardiff climate

Name: Cardiff
Address: GB

Cardiff is warmest in July, with average highs of 19 °C, and coldest in February, when nights average 2.9 °C. December is the wettest month (110 mm) and March the driest (70 mm). Figures are 1991–2020 climate normals.

Across a full year Cardiff averages 1,025 mm of rain, 4 days above 25 °C and 23 days below freezing.

United Kingdom · population 372,089 · 1991–2020 normals

Temperature below 0 °C to above 30 °C Rain band height is that month’s share of the wettest month

Warmest month July 19 °C
Coldest month February 2.9 °C
Driest month March 70 mm
Wettest month December 110 mm
Least cloud July 65 % cloud
Hottest on record August 31 °C
Coldest on record December -11 °C
Warmest sea August 18 °C

What to expectCardiff through the year

Cardiff has a clear annual cycle: average daily highs run from 7.8 °C in February to 19 °C in July, a swing of 11 °C in mean temperature across the year.

Counted across a normal year, 4 days a year reach 25 °C, 0 of them reach 30 °C, 23 nights drop below freezing. The warmest reading in the 1991–2020 record is 31 °C, in August.

Rain is spread fairly evenly through the year, from 70 mm in March to 110 mm in December. There is no dry season to aim for.

The sea off Cardiff is warmest in August at 18 °C and coldest in February at 7.1 °C. Sea temperature lags the air by a month or two, which is why late summer swims warmer than early summer at the same air temperature.

Month by month

Month	Avg high	Rainfall	Cloud
January	7.5 °C	96 mm	74 %
February	7.8 °C	78 mm	71 %
March	9.7 °C	70 mm	70 %
April	12.3 °C	71 mm	65 %
May	15.2 °C	74 mm	66 %
June	17.8 °C	71 mm	66 %
July	19.5 °C	75 mm	65 %
August	19.3 °C	89 mm	67 %
September	17.2 °C	77 mm	67 %
October	13.8 °C	108 mm	71 %
November	10.3 °C	105 mm	73 %
December	7.9 °C	110 mm	73 %

Temperature month by month

Month	Avg high	Avg low	Mean	Record high	Record low	Days above 25 °C	Days below 0 °C
January	7.5 °C	3.2 °C	5.4 °C	13.4 °C	-6.7 °C	0	6
February	7.8 °C	2.9 °C	5.4 °C	15.0 °C	-6.8 °C	0	6
March	9.7 °C	3.8 °C	6.8 °C	17.7 °C	-5.6 °C	0	3
April	12.3 °C	5.5 °C	8.9 °C	22.4 °C	-2.6 °C	0	1
May	15.2 °C	8.4 °C	12.0 °C	25.0 °C	1.0 °C	0	0
June	17.8 °C	11.3 °C	14.7 °C	29.2 °C	5.0 °C	1	0
July	19.5 °C	13.3 °C	16.5 °C	30.7 °C	7.1 °C	2	0
August	19.3 °C	13.3 °C	16.4 °C	31.1 °C	7.5 °C	1	0
September	17.2 °C	11.4 °C	14.4 °C	25.4 °C	4.2 °C	0	0
October	13.8 °C	8.9 °C	11.4 °C	23.4 °C	-0.8 °C	0	0
November	10.3 °C	6.0 °C	8.2 °C	16.6 °C	-4.5 °C	0	1
December	7.9 °C	3.8 °C	5.9 °C	13.9 °C	-11.1 °C	0	5

Rain, sun and wind month by month

Month	Rainfall	Wet days	Daylight	Cloud cover	Humidity	Wind	Sea temp
January	96 mm	14	8.4 h/day	74 %	86 %	27 km/h	7.6 °C
February	78 mm	11	10.0 h/day	71 %	84 %	26 km/h	7.1 °C
March	70 mm	12	12 h/day	70 %	81 %	24 km/h	7.5 °C
April	71 mm	11	14 h/day	65 %	78 %	22 km/h	9.3 °C
May	74 mm	12	16 h/day	66 %	77 %	22 km/h	12.0 °C
June	71 mm	11	17 h/day	66 %	78 %	21 km/h	15.0 °C
July	75 mm	12	16 h/day	65 %	78 %	21 km/h	17.3 °C
August	89 mm	13	15 h/day	67 %	79 %	21 km/h	18.2 °C
September	77 mm	11	13 h/day	67 %	80 %	21 km/h	17.1 °C
October	108 mm	14	11 h/day	71 %	83 %	24 km/h	14.6 °C
November	105 mm	14	8.9 h/day	73 %	86 %	25 km/h	11.6 °C
December	110 mm	14	7.9 h/day	73 %	87 %	26 km/h	9.1 °C

How Cardiff compares

The same four figures for nearby destinations, so the numbers above have something to be read against. Summer high is the warmest month's average high; winter low is the coldest month's average low.

Destination	Summer high	Winter low	Rain per year	Days above 25 °C
Cardiff	19 °C	2.9 °C	1,025 mm	4
Newport · United Kingdom	20 °C	2.5 °C	872 mm	6
Bristol · United Kingdom	20 °C	2.4 °C	790 mm	6
Swansea · United Kingdom	19 °C	3.6 °C	1,232 mm	2
Swindon · United Kingdom	21 °C	1.7 °C	724 mm	7

Where Cardiff ranks

Ranking	Position	Value
The coolest places in Europe in July	30thof 50	19 °C
The coolest places in Europe in June	41stof 50	18 °C
The coolest places in Europe in August	44thof 50	19 °C

Planning a trip? See the best time to visit Cardiff.

QuestionsCommon questions about Cardiff’s climate

When is the best time to visit Cardiff?

That depends on what you want, so the honest answer is a comparison rather than a single month. June, July, August sit closest to 20 °C on average, July is the warmest month and March the driest. The month-by-month table above has the full picture.

How hot does Cardiff get?

In July, the warmest month, daily highs average 19 °C. About 0 days a year pass 30 °C. The highest value in the 1991–2020 record is 31 °C.

How cold does it get in winter?

Nights average 2.9 °C in February, the coldest month. A normal year has 23 nights below freezing.

Which month is wettest in Cardiff?

December, averaging 110 mm over 14 days with rain. The driest month is March with 70 mm. The year as a whole averages 1,025 mm.

Are these figures a forecast?

No. They are 1991–2020 climate normals: the average of thirty years, which describes what a month is usually like in Cardiff rather than what any particular week will bring. Individual years can differ substantially from the normal.

Data sources and method

ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
Open-Meteo — Open-Meteo.com. CC BY 4.0
NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
GeoNames — GeoNames.org. CC BY 4.0

Normal period: 1991–2020
Dataset version: era5-1991-2020-scores1.1
Last processed: 1 August 2026

Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: monthly rankings, daylight hours, beach and comfort scores. Full formulas are on the methodology page.

Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.