Soaring temperatures are expected to hit Australia's east coast today, as extreme early spring heat moves towards New South Wales.
The rising temperatures could even break records for the hottest NRL grand final in history, Bureau of Meteorology senior meteorologist Angus Hines told Weekend Today.
Temperatures are expected to peak around 3pm, as fans start packing Accor Stadium, with the mercury set to drop back to the high 20s by kick-off in the main game between the Penrith Panthers and Brisbane Broncos at 7.30pm.
"It's going to be a warm one across Sydney and New South Wales," Hines said.
"We are forecasting to reach 36 degrees at the stadium and if that comes through it will make it the hottest grand final on record, topping the 34.7 degrees in 2014.
"It's looking to be a scorcher on the field."
That's a whopping 14 degrees above the average October maximum of 22.2 degrees, and not far short of the October record of 38.2 degrees (in stats going back to 1858).
Total fire bans have been issued for greater Sydney, the Hunter, the far south coast and across north-western NSW - with the fire danger rating also sitting at extreme in those areas.
Hines said hot, gusty north-westerly winds are expected to cross the state today, increasing the risk of fires.
"We have all the ingredients for the high fire danger," he said.
"We have the warm sunny conditions, but as the day goes on, we will see the wind pick up across coastal areas and we will see the hot and dry winds build - which means the fire risk increases."
Footy fans sweltered in Melbourne yesterday, peaking at 29.7 degrees during the first quarter of the AFL grand final
Meanwhile, South Australia recorded its hottest September day in 12 years, recording a top of 31.5 degrees.
It will be a sunny and clear day in Brisbane today, with a top of 27 degrees expected, while Darwin will see a top 34 degrees.
It will be a little cooler in Melbourne with a top of 22 degrees, Adelaide 21 degrees, and Hobart 20 degrees.
Meanwhile, there will be a shower or two in Perth with 21 degrees.