I used to live in Darwin, I had forgotton about that- its ridiculous. My work mates would be wearing wooley jumpers and scarves when it was literally 15deg for 1 hour in the mornings of winter- strange.

Have you tried the markets ( Mindil, Parap, Nightcliffe)- they have those fishermans pants etc which might be good.

I'm jealous, Darwin is unreal, have fun xx