last year I had all turtles outside in ponds, snakenecks, red ears and Reeves, depends on age of them.
just keep an eye on them, I had one reeves with an underlying shell rot problem that I brought back in and treated and one red ear started basking a lot so also brought in and treated for mild flu, both ok and outside again.
that is out of 20 odd turtles so pretty good.
Auckland weather similiar to where you find some snakenecks in lower Aussie and Reeves come from climates that get very cold in winter.