Sydney residents sweltered through the hottest start to October, with temperatures soaring 14 degrees above average, as fire crews in several states are preparing for another busy day ahead.
The Observatory Hill weather station spiked at 35.6 degrees at 3:02pm on Sunday, smashing the previous all-time high for 1 October of 33.1C recorded in both 1961 and 2009, according to data from the Bureau of Meteorology.
Ahead of the NRL grand final clash, Penrith soared to 37.3 degrees, Richmond peaked at 36.7 degrees and Sydney Airport's mercury climbed to 36.9 degrees.
The scorching heat created dangerous conditions for firefighters on Sunday, with 85 fires burning across New South Wales alone.
Fire crews in several states have another busy day ahead, as strong winds combine with low humidity across the country's southeast to create dangerous conditions.
The Victorian Country Fire Authority has declared a total fire ban for the Mallee area in the state's northwest for Monday, with the CFA also battling several blazes in the Gippsland region.
An out-of-control fire was burning in difficult terrain north of Maffra on Sunday, with people in Briagolong, Culloden, Moornapa, Stockdale and surrounds told to evacuate.
CFA deputy chief for the southeast Trevor Owen said on Monday morning temperatures had dropped and winds had eased overnight but with 5000 hectares already blackened and the potential for the blaze to make a run east, concern remained.
"We did lose one residence in that area and we're doing some further assessment today on the impact to any other outbuildings," he told ABC radio.
"The fire ran back into the forest ... and that's the one we've been working hard on overnight and obviously yesterday as best we can."
Authorities have issued wind warnings for Monday in South Australia, Victoria and NSW amid concerns strong winds could worsen fire conditions.
A total fire ban is in place in SA for the northeast pastoral, West Coast, and Eastern Eyre Peninsula, with extreme fire danger warnings in place.
The NSW RFS has issued a total fire ban for the southwest region bordering Victoria.
"With hot, dry and windy conditions, high fire danger is forecast for several areas across the state," the warning said.
Temperatures across NSW soared into the 30s on Sunday - about 14C above average in some areas - ahead of a cool change on Monday.
The Western Australia Department of Fire and Emergency Services (DFES) has issued total fire bans for the Goldfields Midlands region for Monday.
An emergency evacuation order was issued late on Sunday in Albany, in the state's south, as a fast-moving fire threatened properties.
At least 70 fires were burning in NSW on Sunday, some 30 of them uncontained.
Fires in Queensland were at advice level, with most advisories to avoid smoke.
