How Hot Is Australia In Summer?

How Hot Is Australia In Summer? During summer, average temperatures range from 18.6 – 25.8°C (65.5 – 78.4°F), and average humidity spikes to 65%. This is a great time to enjoy Sydney’s abundant beaches when water temperatures rise to 21.9 – 23.7°C (71.4 – 74.7°F). How hot was the hottest day in Australia? Australia has