Well, if you like temperatures between 10 and 20C ... Perth, Adelaide, even Melbourne might do. Have a look at the August temps in those areas. Probably Perth would be better than the other two. 10-20C are late autumn & late winter/early spring temps.
It gets quite a bit colder in South Korea than it does here, even in the colder parts of Australia. Tasmania, where we live now, and the part of Victoria where we used to live (in the mountains) are both some of the coldest parts of Australia. But even so it is a rare day when the temps drop below freezing.