Firefighters are throwing air and ground resources at a large, fast-moving grass and scrub fire burning out of control in country Victoria as temperatures near 40C.

An emergency warning was issued for Mount Bolton, north of Ballarat.

"There is a fast-moving, out-of-control grass and scrub fire travelling in a south easterly direction from Laverys Road towards Settlement Rd and the Sunraysia Highway," the CFA said.

Residents in the Mount Bolton and Addington areas have been told it's too late to leave as spot fires and ember attacks are starting up to 1.5 km ahead of the main fire.

A watch and act message has also been issued for nearby towns including Learmonth, Coghills Creek, Glendaruel.


Residents in those areas have been advised to leave.

A CFA spokeswoman said more than 25 tankers are fighting the fire with the help of nine water bombing aircraft.