Weather conditions in Australia in August

I will stay in Australia. It's not cold during the day. Basically, short-sleeved shirts and jackets can be cold at night. However, the temperature difference between morning and evening is large. But the coldest time is when it starts to warm up in August. There are many places to visit now, such as Darwin, Brisbane, Gold Coast and Sydney in the north, not to mention Melbourne's Ocean Road, Penguin Island (if these scenic spots are fast, they can be visited in one day) and the Great Barrier Reef.