Victorians are being urged not to be complacent, with authorities declaring a total fire ban as temperatures and high winds are forecast across large parts of the state.
Melbourne is forecast to reach 37C on Saturday while northern regions could exceed 40C.
Wind gusts of up to 45km/h are also forecast.
The Country Fire Authority declared Saturday a total fire ban day for the Mallee, Wimmera, South West, Northern Country, North Central and Central regions.
CFA chief officer Jason Heffernan said residents in those areas should have a fire survival plan ready to go in case the worst happened.
"Tomorrow is not the day to be complacent," he told reporters on Friday.
"Fires will occur and if they do occur, they will move incredibly fast and you will be required to take action."
Total fire bans require no fires to be lit or remain lit for the duration of the ban, including campfires and for those who have permits for fuel reduction.
People with fuel-reduction permits must postpone any burns until after the ban is lifted.
Residents in built up areas close to the city need to be cautious, Mr Heffernan said.
"In the last couple of weeks, we have seen an increase in grass fires occurring in the outer metropolitan ring of Melbourne," he said.
"It's important that if a fire should start in those areas, rather than get in the car and drive away to safety, we are asking residents to simply walk two streets back.
"It will keep the roads free and allow emergency services to get onto the scene in order to suppress that fire."
Deputy Premier Jacinta Allan urged people to be mindful of their outdoor activities and to limit travel if possible.
"Even though we're not in summer, it's one of those really difficult days that you get from time to time over the summer period where it's hot, its windy, its uncomfortable," she told reporters in Bendigo.
"Following the rain events of last year, there is a lot of grass, a lot of fuel around as it's dried out over the summer period."
A cool change is expected to move through the state on Saturday evening, with temperatures dropping by up to 15 degrees.
"That won't reach the northern and eastern parts of the state until Sunday so expect another hot start to the day up there," Bureau of Meteorology meteorologist Keris Arndt told reporters on Friday.
"But there is relief when that cool change comes through."
The bureau this week declared an end to the cooler, wetter La Nina weather pattern and issued a watch for El Nino, which is associated with drier conditions in Australia and an increased fire risk.
