The Mallee is forecast to experience temperatures in the mid 30s, strong and gusty winds and a risk of thunderstorms on Thursday.

With a severe fire danger rating, the Country Fire Authority has declared the region will be subject to a total fire ban for Thursday.

It means no open air fire can be lit or remain alight from 12.01am to 11.59pm, and strict rules also apply for use of farm machinery, chainsaws and lawn mowers.

A very high fire danger rating is forecast for the nearby Wimmera region on Thursday, while it is deemed high for the Northern Country and South West and low-moderate for the rest of the state.

Meanwhile, emergency services minister Jaclyn Symes says 50 aircraft, including firebombing planes, will be "strategically placed" across Victoria over the summer to help firefighting efforts.

These include the state's highest capacity helicopter, a CH47 Chinook carrying 11,000 litres of water or retardant, which will be used in the hottest part of the day and can continue into the night.

Two large air tankers that can carry 10,000 litres and require less room for takeoff and landing will be based at Avalon Airport, one of which will be shared with Queensland.

"These aircraft are always a critical weapon in our firefighters' arsenal during summer, ensuring that Victoria has the strongest possible fire response each year as we head into the fire season," Ms Symes said.

While the outlook for this fire season indicates a lower threat of prolonged bushfires, grass and crop blazes remain a high risk across the state after average-above average rainfall and strong fuel growth.

"Overall, we've had milder conditions leading into this fire season, but we can't afford to be complacent about these hot and windy days where the fire danger spikes," CFA chief officer Jason Heffernan said.

The Bureau of Meteorology says maximum temperatures will rise up to 10C above average in the state's north by Friday.

Australian Associated Press