Fifteen fires across New South Wales are now at emergency level, with dozens more uncontrolled.
'Catastrophic' fire warnings have been issued for the Sydney, Illawarra and Hunter areas which includes the Blue Mountains and the Central Coast.
More than 3000 firefighters are fighting the blazes on the ground, supported by 60 aircraft.There are also bushfires burning in Queensland, South Australia and Western Australia.
David Bowman is the Professor of Pyrogeography as well as the Fire Science Director of the Fire Centre Research Hub at the University of Tasmania. He speaks with Karyn from their Hobart campus.