Northern Australia - there be crocodiles. North-Western Australia - there be no water. Southern Australia - there be desert. Actually all of Australia - even the bits inhospitable to European settlers - is inhabited by Australia’s indigenous people (who, like indigenous people the world over, were minding their own business until their lands were taken away from them). I’ve no answer to that question but I think you’ll find Christmas Day temperatures at the beach anywhere in Australia would generally be closer to 35 degrees Celsius than 25.