Its very wintery and cold down here in Victoria at the moment, by August it will be freezing, wet and miserable. Queensland should be very nice in August. I think the average top temperature is somewhere in the mid 20's.
The Victorian top temperature is about 14 degrees with lows that can go below zero.
August is a great month to visit Victoria if you want to go skiing.
I live in Ballarat, famous for being cold and wet...also for its gold mining history and and Victorian era street-scapes [link]
I am still heading up to Queensland in August myself. Not sure exactly what week in August just yet.