Parts of Australia face a catastrophic fire risk this Friday as a strong heatwave sweeps across most of the country. Every state and territory, except Queensland, is under severe to extreme heatwave warnings. Victoria has declared a total fire ban and closed 450 schools, childcare centres, and parks in the north. Fire danger there is set at "catastrophic" – the highest level. Meteorologists warn that the mix of extreme heat and fire risk is the worst seen since the 2019-2020 Black Summer fires. Many fires broke out on Thursday in Victoria and New South Wales. Firefighters used a dozen water planes to tackle a large blaze near Wodonga city. Melbourne hit its hottest day in six years on Wednesday, reaching 40.9°C, while parts of Western Australia hit 49°C. In New South Wales, the heatwave will peak on Saturday with Sydney facing 42°C. South Australia and Western Australia expect temperatures over 40°C in the coming days. Angus Hines from the Bureau of Meteorology said Friday is the "real peak" of the heatwave for much of South Australia, Victoria, New South Wales, and parts of Tasmania. Strengthening winds, dry lightning, and little rain increase fire risks. Emergency officials say catastrophic fire danger means fires can be unpredictable and uncontrollable. Victoria's Emergency Management Commissioner Tim Wiebusch urged people to "prepare now and enact your bushfire survival plan" and leave early if in high-risk areas. Australia’s fire risk scale ranks from low to catastrophic, with the latter being the most severe. Heatwaves are declared when unusually high temperatures last at least three days.