Firefighters may never be able to extinguish some of Victoria's largest bushfires without a big soaking of rain, says the state's premier.

It's been weeks since a major rainstorm drenched parts of the state.

A watch and act remains in place for residents of Violet Town, about 170 kilometres north of Melbourne, where a bushfire of about 1300 hectares in size is continuing to burn south of the community.

Firefighters are also working on two controlled fires at Harrietville, near Mount Feathertop in the northeast, and the Aberfeldy fire in Gippsland, to the southwest, that has destroyed homes while burning through 71,000 hectares.

After days of fierce firefighting, townships like Heyfield were saved from the Aberfeldy blaze last week by a cool wind change that swept the fires away from homes.

Victorian Premier Ted Baillieu says no communities are directly under threat at this time but the massive fires will need rain to put them out completely.

"Any of these large forest-based fires are unlikely to be extinguished by hand," Mr Baillieu told reporters on Tuesday.

"They need rainfall to extinguish them finally.

"I know there's a tail of the cyclonic activity from NSW and Queensland that is impacting Victoria in the east at the moment. Let's hope some of that is spared for the Violet Town region."

Bureau of Meteorology senior forecaster Richard Carlyon said it had been a dry month and there would be very little relief from the cyclone system that impacted Queensland and NSW.

"Those fire sites have received no rain from that system," Mr Carlyon said.

The Gippsland region is forecast to receive five to 10 millimetres of rain on Thursday and Friday while the area around Violet Town will see about five millimetres on Thursday, Mr Carlyon said.

"It will be handy but we probably need heavy and more widespread rain to ease the fire situation," he said.

State control centre spokesman Stephen Walls said 100 firefighters were working on the Violet Town blaze in difficult terrain.

"If we don't get favourable weather conditions the only way to ensure it's out is to get significant rainfall, because getting into some of those areas to black out by hand is very difficult."

Milder conditions had allowed firefighters to work on consolidating fire control lines.