Beach
Williamstown Beach
City of Hobsons Bay, Australia · sea 20.7 °C at its warmest, in February

Sea temperature month by month
Monthly means in °C, NOAA OISST v2.1 climatology 1991–2020.
About
Beach in Williamstown, Victoria, Australia
Wikipedia has no article about this beach yet. It is on the atlas from its Wikidata record and its photograph.
Questions
How warm is the sea at Williamstown Beach?
The sea off Williamstown Beach averages 20.7 °C at its warmest, in February, and 11.1 °C at its coolest. These are monthly means from NOAA's OISST v2.1 satellite and buoy record for 1991 to 2020, sampled at the beach's own coordinates.
When can you swim at Williamstown Beach?
The sea reaches 20 °C or more from January to February. Twenty degrees is where most swimmers stop calling water cold; below it, a wetsuit helps.
Where is Williamstown Beach?
Williamstown Beach is on the coast of City of Hobsons Bay, Australia, at -37.8671, 144.8908. The map on this site flies straight to it.