Adelaide has recorded Australia's hottest ever capital city temperature - a sweltering 46.6C - during a day that toppled records across South Australia.
The historic heat was recorded at 3.36pm on Thursday, topping Adelaide's previous hottest day of 46.1C set in January, 1939.
The reading also beats Melbourne's 2009 record of 46.4C to claim the hottest temperature ever recorded in an Australian capital city.
But the mercury rose even higher across the state, with Port Augusta the hottest reading at 49.5C and the fourth hottest temperature recorded in South Australia.
The town was one of more than 20 locations to experience record-breaking highs, others including Ceduna at 48.6C, and Port Pirie and Whaylla at 48.5C.
The unprecedented heat across southern Australia prompted the market operator to call on SA's fleet of diesel generators for the first time, amid scarce power supplies in Victoria.
At the time, South Australia was meeting its own demand using local supplies including wind and gas power, and had avoided load-shedding blackouts.
The heat also took its toll on the health system as 44 people presented to emergency departments with heat-related illnesses - 12 of those admitted for further treatment.
Total fire bans remain in place in 13 districts until midnight, while fire danger conditions have reached extreme levels in the Mount Lofty Ranges, the Kangaroo Island, Lower Eyre Peninsula and the Lower South East districts.
A cool change is expected to sweep across the state overnight, with a top of 31C expected in Adelaide on Friday.
The heat will move east, as Melbourne braces for a forecast maximum of 44C on Friday - the hottest maximum temperature since it hit 46.4C on Black Saturday in 2009.
Australian Associated Press