Swansea, United Kingdom
Irish Sea51.59°N, 3.96°WStation UN-SWA-SWA

Swansea Bay Sea Water Temperature

A temperate beach on the Irish Sea, warmest around August at about 18°C. Today's reading, 7-day forecast, and monthly averages below.

Live readings · auto-updating
Water Temperature NowBuoy & Sentinel-3 SST

Swansea Bay water temperature

17.4
63.3°FCool / Refreshing (16°C – 20°C)

Invigorating and crisp. Tolerable for active swimming, but chilly for prolonged casual bathing.

+0°vs Sep avgIrish Sea51.59°N, 3.96°W
Activity Index:SwimmingSnorkelingSurfingTypical conditions
Marine Atmosphere Grid Live Marine Feed
Coastal Air
19°C
66°F onshore
Wind Speed
12 km/h
Surface wind
Wave Height
0.8 m
Slight shore chop
Swell
0.6 m
Deep water swell
Wave Period
6 s
Peak interval
UV Index
—
Daily maximum
Sunrise
—
First morning light
Sunset
—
Golden hour close

7-Day Water Temperature Forecast

Open-Meteo ocean model
Today
WedSep 30
17.4°C
63.3°F
Waves: 1m
Refreshing
ThuOct 1
17.7°C
63.9°F
Waves: 0.9m
Refreshing
FriOct 2
17.8°C
64°F
Waves: 0.7m
Refreshing
SatOct 3
17.7°C
63.9°F
Waves: 0.6m
Refreshing
SunOct 4
17.4°C
63.3°F
Waves: 0.7m
Refreshing
MonOct 5
17.1°C
62.8°F
Waves: 0.9m
Refreshing
TueOct 6
17°C
62.6°F
Waves: 1m
Refreshing
Forecast cooling trend: -0.4°C over 7 days at Swansea Bay.
Confidence: High

Swansea Bay Monthly Water Temperature Averages

Historical monthly climatology. The warmest water in Swansea Bay occurs inJuly, August, September, October — peaking at18°C (64.4°F) in August.

Year-Round Water Temperature Curve (°C / °F)

Hover a bar for details
Current month Comfortable (20–24°C) Warm (24°C+) Cool (<20°C)
8
Jan
8
Feb
8
Mar
9
Apr
12
May
15
Jun
17
Jul
18
Aug
Current
17
Sep
16
Oct
13
Nov
10
Dec
Full 12-month data table — min / avg / max & swimming comfort
MonthMin Water TempAverage Water TempMax Water TempSwimming Comfort
January6.1°C8.3°C9.9°CVery Cold (< 16°C)
February6.2°C7.6°C8.9°CVery Cold (< 16°C)
March6.4°C7.8°C9.3°CVery Cold (< 16°C)
April7.6°C9.4°C11.3°CVery Cold (< 16°C)
May9.7°C11.6°C14°CVery Cold (< 16°C)
June12.8°C14.5°C16°CVery Cold (< 16°C)
July15°C16.6°C18.2°CCool / Refreshing (16°C – 20°C)
August16.7°C18°C18.8°CCool / Refreshing (16°C – 20°C)
SeptemberCurrent15.8°C17.4°C19.3°CCool / Refreshing (16°C – 20°C)
October13.4°C15.5°C17.4°CVery Cold (< 16°C)
November10.4°C12.5°C14.7°CVery Cold (< 16°C)
December8.6°C9.7°C11.7°CVery Cold (< 16°C)

Swimming FAQs for Swansea Bay

Is the sea warm enough to swim in Swansea Bay today?

Typical sea surface temperature in Swansea Bay this time of year is 17.4°C (63.3°F) — classified as Cool / Refreshing (16°C – 20°C). Invigorating and crisp. Tolerable for active swimming, but chilly for prolonged casual bathing. Live readings load automatically.

What are the warmest months for swimming in Swansea Bay?

The highest water temperatures in Swansea Bay typically occur duringJuly, August, September, October, when monthly averages reach peak seasonal levels.

What is the typical water temperature in Swansea Bay in September?

Historically in September, water temperatures in Swansea Bay average around17.4°C (63.3°F), fluctuating between a recorded minimum of 15.8°C and a maximum of 19.3°C.

Other Beaches in United Kingdom

Explore all United Kingdom stations

Swansea Bay Coastal Zone Map

Live OpenStreetMap