Thousands of Victorian firefighters are on high alert as the state braces for some of the worst bushfire danger since the deadly Black Saturday fires.
But fire authorities say they are well prepared for the threat and have learnt much since 173 people were killed in 2009.
Many parts of the state are expected to experience temperatures above 40C until mid-next week, with an extreme fire rating declared in the southwest region for Friday.
Country Fire Authority (CFA) state duty officer Tony Bearzatto says about 8000 firefighters from the CFA, Department of Sustainability and Environment (DSE) and Metropolitan Fire Brigade (MFB) are on standby.
Forty aircraft, including two aircranes, are also ready to be called into action.
He while no total fire ban has been declared in Victoria on Thursday, most regions have fire restrictions.
Mr Bearzatto has urged Victorians to avoid doing anything that might spark a fire, particularly farmers using machinery for harvesting.
"Today's very hot statewide, with fire danger ratings high to very high in most parts of the state," he said.
"Tomorrow we're expecting hotter and drier and windier conditions with extreme fire danger ratings in the southwest and the Wimmera area, which is the first for the season, and severe fire danger ratings for the rest of the state, except east Gippsland."
Mr Bearzatto said while conditions were extreme, they were not as bad as the lead-up to Black Saturday.
"The conditions in 2009 were worse than they are now and of course we also had a longer drying period and longer period of drought prior to 2009," he said.
"But having said that, it doesn't mean that the risk is any less.
"We're still talking about extreme conditions where the fires will quickly become uncontrollable and unpredictable and fast-moving, so people need to be aware of that and plan accordingly."
Mr Bearzatto said the state was better prepared to respond to major bushfires.
"We certainly have improved structures in place, better work between agencies and also communication procedures and information flow to the public," he said.