Beach
Katten
Oslo Municipality, Norway · sea 18.4 °C at its warmest, in August

Sea temperature month by month
Monthly means in °C, NOAA OISST v2.1 climatology 1991–2020, sampled 54 km offshore, at the nearest open water cell of a 0.25° grid.
About
Katten is a municipal beach in Bunnefjorden in the Nordstrand area in Oslo, Norway. The beach is suitable for children and comprises a sheltered, sandy beach, rocks and grassy hills.
Questions
How warm is the sea at Katten?
The sea off Katten averages 18.4 °C at its warmest, in August, and 2.7 °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 Katten?
The sea here never averages 20 °C in any month, so swimming means cold water all year. Some people do it anyway.
Where is Katten?
Katten is on the coast of Oslo Municipality, Norway, at 59.8553, 10.7833. The map on this site flies straight to it.