I think the sea is warmer AFTER the intense part of the summer (July & Aug) than before.

I've been to Olu in June & thought the open sea too cold to bathe, but the lagoon nice. In fact that lagoon is the only place I really like swimming.

Mind you I've been back a couple of weeks & the sea temperture difference between Turgutreis (where we stayed) & Gumsluck a few miles down the road was quite different.

But then take no notice of me, I'm a wooss who likes the sea as warm as a bath.

sea temperatures are not that bad at the moment warmer than the pools in hisaronu and olu

Went to Olu Deniz last year for 2 weeks starting 14th of june. The sea was cold for the first week but it is so beautiful that you soon get used to it esp., as unlike here it is lovely and warm when you get out. Children rarely seem to freak out about water temperatures in the way us adults do anyhow.

The second week the sea was much warmer at the surface. But the sun was really very, very hot. We had to be really careful as we are not sun people and we were frying in minutes.

I think that you made the right choice to go early in June with a young child. Cold sea is far less of a concern than heat with very young ones i would think.

All that said we are going back for last week in June this year. It simply came down to time management in the end.