Swansea weather in July

Name: Swansea
Address: GB

In July, Swansea has daytime highs averaging 19 °C, nights around 13 °C, with 15 wet days, and a sea temperature of 16 °C. Figures are 1991–2020 climate normals.

18.6°C Average high
13.4°C Average low
15days Wet days
95mm Rainfall
16.4°C Sea temperature
16h Daylight

Daily temperatures through July

Daily highDaily low Day of month on the horizontal axis. Highs peak at 19.8 °C and lows bottom out at 12.6 °C.

How July develops

Averages for the first, middle and last part of the month, from daily 1991–2020 normals. Chance of rain is the share of years in which that calendar day recorded more than 1 mm.

Days	Avg high	Avg low	Chance of rain
1–10 July	18.2 °C	13.1 °C	53 %
11–20 July	18.5 °C	13.5 °C	48 %
21–31 July	18.9 °C	13.7 °C	45 %

Rain is most likely over days 1–10 of July (53 % of days) and least likely over days 21–31 (45 %).

Chance of a wet day (over 1 mm) by date in July. Wettest date over the 30 years: July 3, at 60 %. Single dates are noisy — read the shape, not the spikes.

What to expect

Measure	Typical July	Share of the month
Days above 25 °C	0.8 of 31	2 %
Days above 30 °C	0 of 31	0 %
Days below 0 °C	0 of 31	0 %
Days with more than 1 mm rain	15 of 31	48 %

Conditions in July

Measure	Average
Mean temperature	16 °C
Record high (1991–2020)	30 °C
Record low (1991–2020)	6.8 °C
Relative humidity	81 %
Wind speed	20 km/h
Cloud cover	69 %

Where Swansea ranks in July

Ranking	Position	Value
The coolest places in Europe in July	20thof 50	19 °C

July compared with the months around it

Month	Avg high	Rainfall	Cloud
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 %

See all twelve months for Swansea

July is the warmest month in Swansea.
It is the 7th driest month of the year.
It ranks 5th for least cloud cover.
Days last about 16 hours from sunrise to sunset.
It rains on 15 of 31 days — 48 % of the month.
Nights are about 5.2 °C cooler than the middle of the day.
The hottest July day on record since 1991 reached 30 °C, 11 °C above the usual daytime high.
Beach score: 25 / 100 — see how this is calculated.

Nearby destinations in July

Destination	Avg high	Wet days	Sea
Swansea	19 °C	15	16
Cardiff	19 °C	12	17
Newport	20 °C	11	18
Bristol	20 °C	11	18

QuestionsJuly in Swansea, answered

How warm is Swansea in July?

Daily highs average 19 °C and nights fall to about 13 °C, a spread of 5.2 °C between afternoon and dawn. That makes July the 2nd warmest month of the year here.

Does it rain much in Swansea in July?

July averages 95 mm of rain, spread over about 15 of the 31 days — 48 % of the month. Cloud cover averages 69 % of the sky.

Is the sea warm enough to swim in July?

The sea averages 16 °C off Swansea in July. Most people find water below 20 °C bracing and above 25 °C comfortable for a long swim; this figure is a monthly surface average, so a sheltered bay on a still afternoon can be warmer.

How long are the days in July?

Swansea averages 16 hours between sunrise and sunset in July. Day length is computed from latitude and date, so it is exact rather than modelled — but it says nothing about how much of that time is sunny.

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: daylight hours, beach and comfort scores, monthly rankings, threshold day counts, chance of a wet day by date, ten-day averages within the month. 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.