Residents in the far east of the Australian state of Victoria have been urged to flee an out-of-control blaze amid what authorities are predicting will be a "significant fire and weather day" in the state's history.

In what has been the strongest warning yet, Emergency Services Commissioner Andrew Crisp urged anyone in the Gippsland area — including locals, tourists and long-haul truckies — to leave today ahead of a horror forecast tomorrow.

There are an estimated 30,000 holiday-makers in the region right now, many of believed to be camping in the heavily forested area.

Temperatures are expected to reach the mid-40s in several cities across the state but strong winds and thunderstorms may render firefighting aircraft unable to fly.

Meteorologist Kevin Parkes said if temperatures reached the heights predicted for a third day running, it would be the first time since 1897 that had occurred.

Mr Crisp said it was predicted the fires would impact the Princes Highway and warned those who did not take advantage of current conditions to flee risked getting trapped in the area.

"When you consider the Princes Highway is the only way in and out of that part of the state, you could be stuck in East Gippsland for a number of days, because already we've closed the Bonang Rd because of the risk in that part of the East Gippsland," he said.

"The Great Alpine Rd is also closed. There isn't too many ways in and out of the state. It is important you think very, very seriously about leaving."

Mr Crisp urged residents and visitors to register at the "Register. Find. Reunite" website to allow authorities to keep track of people moving around the state. Anyone camping in the region should get out now.

"There is a lot of state park. There is a lot of forested areas. No doubt there are people that are camping in those areas. That's the last place that you should be," he said.

"Even today, but particularly tomorrow. You should not be in parks or camping in the forest. Parks Victoria are looking at closing all the parks. We are giving you fair warning — you should not be in the parks.

"You might think you know where the fires are. There could be no fires that start and they could be close to you. You might not find a way out of where you are at the moment. This is something we are taking very, very seriously.

"We've got more than 550 forest fire management Victoria people working on the fires.

"They won't be working on the fires tomorrow. They will be coming off those fires. They will be moving into protect communities."

Mr Crisp warned that while 1000 firefighters and 60 trucks were on standby, "rest assured there aren't enough trucks to go around".

"So, don't count on a fire truck protecting your particular house," he said. "You need to get out of there. Again, we are well resourced in relation to aviation. So, we will have more than 70 helicopters and aeroplanes working tomorrow, doing everything they can.

"However, the conditions are highly likely to be that they can't fly. We have heard great stories about helicopters and planes saving houses. Don't count on those helicopters and planes tomorrow. While we will do everything we can, we are asking you to now leave East Gippsland from that area, east of Barnesdale. Along the coast there, into the parks, into the forest. You should not be there tomorrow. And we want you to get out now."

An emergency warning is in place for Bonang, Cabanandra, Deddick Valley, Dellicknora, Tubbut and Amboyne, in the state's East Gippsland region, with people urged to leave immediately

"Leaving now is the safest option, before conditions become too dangerous," the

alert first issued on Saturday night said.

"Emergency services may not be able to help you if you decide to stay."

People at nearby Goongerah and Martins Creek were also told to flee the fire burning easterly towards their communities.

Police have been doorknocking in the area over the past two days.

A total fire ban will be in place for the Mallee district in Victoria's northwest, with the ban extending to the entire state tomorrow.

The Bureau of Meteorology's Kevin Parkes said tomorrow was likely to be a "significant fire and weather day in Victoria's history", with temperatures expected to reach the mid 40s in most cities.

"In fact, we are going for 43 degrees in Melbourne, 44 degrees in Mildura and Swan Hill, even in the areas where we are seeing fires in Easts Gippsland, temperature also be in the 40 degrees," Mr Parkes said.

"If we do see 40 breached in Melbourne, that will be the third time this month. We

haven't seen those sort of temperatures for three days in December in Melbourne since 1897. So, it's been a long time."

Damaging winds are also forecast for the state's southwest, including The Otways, parts of central Victoria from Geelong to Melbourne and the Alpine region, where gusts of 90 to 100km/h were expected.

Thunderstorms and dry lightening were expected in the north and east, which could spark more fires, he said.