Arriving to Melbourne at the end of February

Hello all: I am so glad you guys exist :-)

I will be coming from Chicago to Melbourne (for a PhD) in a couple of weeks and have never been in Australia before. I cannot figure out how should I pack. I will probably be wearing winter clothes arriving from cold Chicago to Australian end of summer so I have to figure out how to handle that first :-) I read that it can rain a lot over there. True? Suggestions regarding weather/appropriate clothing much appreciated.
Thanks and will be looking forward to meeting you all,
Alma