Communities will be threatened and lives put at risk if serious bushfires break out in South Australia amid severe conditions on Wednesday, the Country Fire Service says.
Assistant chief officer Rob Sandford said conditions across most of the state would be some of the worst ever experienced in April.
"People will be put at risk tomorrow if fires start," Mr Sandford told reporters.
Total fire bans will be in force in 10 South Australian districts as temperatures push into the mid to high 30s for the fourth day in a row.
Severe bushfire conditions have been declared in nine of those while the risk will be extreme across the Mount Lofty Ranges.
Strong winds, forecast to reach up to 50km/h, will add to the fire danger.
"Normally in April we would start to see milder conditions," Mr Sandford said.
"But because of the lack of rain across the state, the really dry conditions have been sustained and we're seeing fire behaviour that we would normally see earlier in the year.
"People need to be aware of that and be vigilant."
On Tuesday the CFS battled two serious fires, one at Birdwood, in the Adelaide Hills, and one at Stansbury on Yorke Peninsula.
The Birdwood fire was sparked by a failed water pump on a local property and destroyed about 35 hectares of stubble.
The Stansbury blaze was a burn-off that got out of control and destroyed about 350 hectares.
Mr Sandford said the CFS was concerned about the speed with which both of those fires got up and running.
The Bureau of Meteorology predicts Adelaide will have a top temperature of 36C on Wednesday.
But it says a cool change will move across SA late in the day bringing much milder conditions for the rest of the week with temperatures in the low 20s.
Adelaide could also get as much as 25mm of rain spread across the four days from Friday to Monday.
But Mr Sandford said that would not be enough to signal a permanent change in the fire danger.
He said season-breaking rains of up to 150mm would be required to significantly change the risk profile.
