Fire Services Commissioner Crag Lapsley warns that everyone should keep their mobile phones close to them while they sleep in case emergency warnings are sent out.
Mr Lapsley says several extended heatwaves, followed by the current high temperatures, have pushed the state's fire danger rating to extreme in six districts.
He says temperatures are also forecast to remain high overnight, meaning firefighters won't see a lull in fire activity before temperatures rise again on Sunday morning, followed by an afternoon wind change.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
"All Victorians should know that tomorrow, fires will run and run hard. Fire intensity, they will be furios, they will be fast, they will be out of control and people need to be very aware of that."
