River & lake beach
Alexander Meghna Beach
Char Alexander Union, Bangladesh · sea 29.3 °C at its warmest, in October

Sea temperature month by month
Monthly means in °C, NOAA OISST v2.1 climatology 1991–2020, sampled 55 km offshore, at the nearest open water cell of a 0.25° grid.
About
beach at Char Alexander union of Lakshmipur in Bangladesh
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 Alexander Meghna Beach?
The sea off Alexander Meghna Beach averages 29.3 °C at its warmest, in October, and 21.5 °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 Alexander Meghna Beach?
The sea reaches 20 °C or more from All year. Twenty degrees is where most swimmers stop calling water cold; below it, a wetsuit helps.
Where is Alexander Meghna Beach?
Alexander Meghna Beach is on the coast of Char Alexander Union, Bangladesh, at 22.6481, 90.9249. The map on this site flies straight to it.