Parts of south-east Australia are warned to expect a heatwave, with temperatures expected to rise in Victoria and Tasmania from this afternoon and the mercury set to soar above 40 degrees on Saturday.
Temperatures will skyrocket in Sydney's west, with the Bureau of Meteorology forecasting highs of 45 in Penrith, 44 in Richmond and 43 in Liverpool, Blacktown and Campbelltown on Sunday.
It is expected the hot weather in the Sydney area will last until early next week before a cool change.
Canberra is expected to reach 36 degrees Celsius on Saturday, and the overnight low is predicted to remain well above 20C.
The warm overnight temperatures will lead into an even hotter Sunday at 38C, with the chance of late rain.
No fire bans have been implemented in NSW or the ACT at this stage, but a total fire ban has been issued for the whole of Victoria on Saturdayand Tasmania is alsofacing a state-wide fire ban, with temperatures expected to be in the mid-30s and northerly winds gusting up to 90 kilometres an hour.
Acting deputy chief officer Jeremy Smith said the Tasmanian Fire Service was preparing for an uncontrollable fire risk with extra crews and additional aircraft.
"Any fire that is currently burning needs to be extinguished and we want to reinforce to the community if you've had a fire had a campfire in the proceeding weeks or even months, we want them to be checked and fully extinguished prior to Saturday," Mr Smith said.
Emergency Management Commissioner of Victoria Craig Lapsley said Saturday would be the "first hot day" of a "mild summer" for the state.
"It's about heat, it's about fire," Mr Lapsley said.
"We're going to see a day that is hot, dry and windy and if we have winds running in the afternoon — if there is fire — that will change the trajectory of the fire and traditionally that is where we lose our property, after the wind change," he said.
"It is a day with everything in it. The key message for Victorians is to be prepared."
The Bureau has warned Sydneysiders to check on elderly neighbours.
"Heatwaves can particularly affect vulnerable people, so the sick, the elderly and children," BOM duty forecaster Rob Taggart said.
"People should check up on their elderly neighbours, stay in cool conditions, keep hydrated and make sure that you're looking after those who might be vulnerable."