Swansea climate

Name: Swansea
Address: GB

Swansea is warmest in July, with average highs of 19 °C, and coldest in February, when nights average 3.6 °C. December is the wettest month (137 mm) and April the driest (76 mm). Figures are 1991–2020 climate normals.

Across a full year Swansea averages 1,232 mm of rain, 2 days above 25 °C and 14 days below freezing.

United Kingdom · population 300,352 · 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 3.6 °C
Driest month April 76 mm
Wettest month December 137 mm
Least cloud April 66 % cloud
Hottest on record July 30 °C
Coldest on record December -7.8 °C
Warmest sea August 18 °C

What to expectSwansea through the year

Swansea has a clear annual cycle: average daily highs run from 7.9 °C in February to 19 °C in July, a swing of 10 °C in mean temperature across the year.

Counted across a normal year, 2 days a year reach 25 °C, 14 nights drop below freezing. The warmest reading in the 1991–2020 record is 30 °C, in July.

Rain is spread fairly evenly through the year, from 76 mm in April to 137 mm in December. There is no dry season to aim for.

The sea off Swansea is warmest in August at 18 °C and coldest in February at 7.5 °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	7.7 °C	124 mm	74 %
February	7.9 °C	95 mm	72 %
March	9.5 °C	83 mm	70 %
April	11.8 °C	76 mm	66 %
May	14.7 °C	83 mm	67 %
June	17.0 °C	86 mm	69 %
July	18.6 °C	95 mm	69 %
August	18.6 °C	100 mm	70 %
September	16.9 °C	93 mm	69 %
October	13.8 °C	133 mm	72 %
November	10.6 °C	127 mm	74 %
December	8.3 °C	137 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	7.7 °C	4.0 °C	5.9 °C	12.9 °C	-5.3 °C	0	4
February	7.9 °C	3.6 °C	5.8 °C	15.1 °C	-6.1 °C	0	4
March	9.5 °C	4.4 °C	7.0 °C	17.0 °C	-5.4 °C	0	2
April	11.8 °C	6.0 °C	9.0 °C	21.4 °C	-1.6 °C	0	0
May	14.7 °C	8.8 °C	11.9 °C	24.6 °C	1.7 °C	0	0
June	17.0 °C	11.5 °C	14.4 °C	28.0 °C	5.3 °C	0	0
July	18.6 °C	13.4 °C	16.1 °C	29.9 °C	6.8 °C	1	0
August	18.6 °C	13.7 °C	16.2 °C	29.4 °C	8.3 °C	1	0
September	16.9 °C	12.0 °C	14.5 °C	24.3 °C	4.7 °C	0	0
October	13.8 °C	9.6 °C	11.7 °C	22.3 °C	-0.5 °C	0	0
November	10.6 °C	6.8 °C	8.7 °C	16.1 °C	-3.5 °C	0	1
December	8.3 °C	4.6 °C	6.5 °C	13.5 °C	-7.8 °C	0	3

Rain, sun and wind month by month

Month	Rainfall	Wet days	Daylight	Cloud cover	Humidity	Wind	Sea temp
January	124 mm	16	8.3 h/day	74 %	85 %	26 km/h	8.1 °C
February	95 mm	13	9.9 h/day	72 %	83 %	25 km/h	7.5 °C
March	83 mm	13	12 h/day	70 %	82 %	23 km/h	7.7 °C
April	76 mm	13	14 h/day	66 %	79 %	22 km/h	9.2 °C
May	83 mm	14	16 h/day	67 %	78 %	21 km/h	11.4 °C
June	86 mm	14	17 h/day	69 %	80 %	20 km/h	14.1 °C
July	95 mm	15	16 h/day	69 %	81 %	20 km/h	16.4 °C
August	100 mm	15	15 h/day	70 %	81 %	20 km/h	17.7 °C
September	93 mm	12	13 h/day	69 %	81 %	21 km/h	17.2 °C
October	133 mm	15	11 h/day	72 %	82 %	24 km/h	15.0 °C
November	127 mm	16	8.9 h/day	74 %	84 %	24 km/h	12.3 °C
December	137 mm	15	7.8 h/day	73 %	85 %	25 km/h	9.7 °C

How Swansea 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
Swansea	19 °C	3.6 °C	1,232 mm	2
Cardiff · United Kingdom	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

Where Swansea ranks

Ranking	Position	Value
The coolest places in Europe in July	20th of 50	19 °C
The coolest places in Europe in June	27th of 50	17 °C
The coolest places in Europe in August	30th of 50	19 °C
The coolest places in Europe in May	45th of 50	15 °C

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

QuestionsCommon questions about Swansea’s climate

When is the best time to visit Swansea?

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

How hot does Swansea get?

In July, the warmest month, daily highs average 19 °C. The highest value in the 1991–2020 record is 30 °C.

How cold does it get in winter?

Nights average 3.6 °C in February, the coldest month. A normal year has 14 nights below freezing.

Which month is wettest in Swansea?

December, averaging 137 mm over 15 days with rain. The driest month is April with 76 mm. The year as a whole averages 1,232 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 Swansea 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
Data point: 51.621°, -3.943° (the coordinates the reanalysis values are taken for)
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.