Victorian authorities are preparing for the one of the worst fire danger days since the Black Saturday bushfires of 2009.
More than 8,000 firefighters are on alert and a total fire ban has been declared across the state for today.
Similar warnings , while there are .
In Victoria, temperatures are expected to hover around or above 40 degrees Celsius for the next six days.
The entire state will experience heatwave conditions, but southern areas will get some reprieve from a weak cool change on tomorrow.
At Mildura, temperatures are expected to hover between 40C and 44C.
Meteorologist James Taylor says it is the longest run of extreme heat since 2009.
"Currently we are forecasting temperatures as high as 44C across the northern part of the state over the next week or so," he said.
"We could potentially see temperatures a degree or so higher than that.
"The record for January, for Victoria, is 47.2 degrees and that was on January 10, 1939."
Emergency officials say the in south-western Victoria and the Wimmera tomorrow and severe just about everywhere else except East Gippsland.
Fire Services Commissioner Craig Lapsley says 41 aircraft are on stand-by and authorities are well prepared.
But he says the community also needs to be on alert.
"We've got absolutely everything in place. We've had small fires over the last number of days so we're not fatigued, we've got all out trucks back in stations," he said.
"We've certainly put the time to put ourselves into the right position at a very high readiness level.
"What that actually means though [is any fires will] run hard, they'll run fast, they'll be uncontrollable."
Firefighters have already brought a grass fire near Shepparton under control.
The blaze broke out at Arcadia South about 5:30am (AEDT) on Thursday.
CFA crews were also attending a small grass fire in the Mia Mia area, south of Lake Eppalock.
As the weather heats up, Deputy Premier Peter Ryan says known arsonists will be the target of specially trained police during days of high bushfire risk.
Mr Ryan is defending the Government's network of arson specialists which was announced last year as part of a bushfire prevention strategy.
A senior police officer has reportedly disputed the description of the bushfire, arson and explosives specialist group as a taskforce.
It is also claimed police may have no idea if a convicted arsonist is living locally.
Mr Ryan says people identified as convicted arsonists are placed on a police database and kept under watch on high-risk days.
"The fact is we now have a network of about 150 experienced police who are located right across Victoria, particularly in the high bushfire risk areas, who are trained as bushfire arson and explosive officers and they are there to combat the ever-present threat of arson," he said.
Mr Ryan is refusing to go into detail about how police target arsonists in an operational sense.
"Be assured those who are in the high-risk category, they are on the LEAP database; police do know who they are and these people are in different ways the focus of additional attention."
© ABC 2013
12:38 EST Tropical Cyclone Jack has rapidly developed over the warm waters of the Indian Ocean in the past 24 hours, making it the 10th system to be named this season.