A is in effect across Victoria today, as fire authorities brace for some of the worst bushfire conditions since the Black Saturday bushfires.
The next six days are expected to be the hottest period since the 2009 bushfire season.
Temperatures are forecast to top 40 degrees Celsius in many parts of the state.
Mildura is expecting a run of five days over 40C.
Victorians sweltered through a hot night, with temperatures in Melbourne not dropping below 23.7C.
Richard Carlyon, from the Bureau of Meteorology, says the cool change will not arrive in Melbourne until sometime between 9:00pm and midnight.
"It will be above 40C for quite a few hours before that cool change moves through," he told ABC local radio.
"Right through the weekend, temperatures [will remain] in the low 40s across northern Victoria.
"It's just the wind direction saving Melbourne from further heat [on the weekend.]"
And he says there is little respite from the hot weather in the coming week.
"Even if Melbourne does have some cool days in the next week they very hot air won't be too far away," he said.
"Any northerly winds mean hot weather for Melbourne."
The Bureau of Meteorology says in the the next few days.
Countrywide, the average temperature on Wednesday was 39.21 degrees, just below the record set in December 1972.
Meanwhile, 8,000 firefighters are on the highest level of alert, with gusty northerly winds expected to create challenging conditions, especially in the state's north-west.
The CFA's is back online, after problems this morning.
Web users had been reporting the website was running slow, or not working at all.
Fire Services Commissioner, Craig Lapsley, says while authorities are well prepared to deal with the threat, the high winds will make it difficult to control a fire once it starts.
"So it is important to understand where you are. The conditions are conducive to run a fire," he said.
"Have a plan, understand where you are, understand what you need to do."
Holiday-makers are also being urged to familiarise themselves with the local area.
Police are warning they will be out in force in high risk areas today to make sure no fires are deliberately started.
Assistant Commissioner Steve Fontana wants people to call Crime Stoppers or triple-0 if they see any suspicious behaviour.
"We're asking the community if they see anything suspicious, please ring police.
"If they have any information about people who might be involved in this type of activity, to call Crime Stoppers.
"If they see it [suspicious activity] on the day, particularly on high risk days, please call triple-0 so that we can respond."