Temperatures in summer are warm to very warm . The average maximum temperatures range from 28 Â C ( 82 Â F ) around Canberra and Queanbeyan to 22 Â C ( 71 Â F ) on the highest parts of the plateau . Temperatures in summer are warm to very warm , with average maxima ranging from 28 Â C ( 82 Â F ) around Canberra and Queanbeyan to 22 Â C ( 71 Â F ) on the highest parts of the plateau .