Get Keen: Melbourne's Copping Its First 30-Degree Day In Seven Months Tomorrow

Victoria is set to experience a burst of heat with temperatures expected to climb to 40C in parts of the state, sending the fire danger soaring.

The hottest conditions will be in the north on Thursday before a cool front arrives bringing milder weather over the weekend, the Bureau of Meteorology Victoria said.

Melbourne could see temperatures as high as 33C, marking its hottest day since March.

Temperatures will build in the north to the mid-30C on Wednesday and reach 40C in parts on Thursday, with winds bringing an increased fire risk.

But the hot spell will be short-lived.

"A cool change will move through on Friday," meteorologist Richard Carlyon said on Tuesday.

"It will be hot at first in northern and eastern parts, but by the end of the day we will see the cooling-off effect from that cold front."

More fire restrictions have been announced in northwest Victoria, as forecasters predict drier and warmer conditions in the coming months.

The fire danger period will begin in Mount Alexander Shire on Monday, weeks earlier than it has traditionally, the Country Fire Authority (CFA) said.

"Low winter rainfall across the northwest means the grass and bush are dry and the fire potential is further increased by Bureau of Meteorology forecasts that the next three months will be drier and warmer than average," regional operations manager Bill Johnstone said.

He urged the local community to "use common sense and take responsibility" for preventing fires.

- AAP