Australia is facing a “perfect storm” of fire conditions as its bushfire season officially begins amid record heat.

Firefighters battled 85 active fires in New South Wales alone last night, with 39 of those not contained, an alert issued by the New South Wales Rural Fire Service stated last night.

The fires come as Sydney sweltered through its hottest-ever start to October, registering 37.3C at a weather station in the city’s west yesterday.

That smashes the previous record of 33.1C recorded at Observatory Hill in 1961 and 2009.

The bushfire season began in New South Wales and other states yesterday and NSW Emergency Services minister Jihad Dib warned locals of the heightened risk, NCA Newswire reported.

“Not only is it hot, it’s dry and it’s windy and those conditions combined are the perfect storm for the fire to run through,” Dib said.

Fire and Rescue NSW acting commissioner Megan Stiffler urged residents to be aware of warnings.

“We can’t ensure a fire truck will be at every house that’s put under threat so it’s really up to you to make sure your bushfire survival plan is in place,” she said.

In Victoria, a bushfire north of Maffra led to authorities to tell residents of Briagolong, Culloden, Moornapa, Stockdale and surrounding areas to leave immediately.

By last night that order had been replaced by a “watch and act” message that instructed residents to “prepare to evacuate immediately”.

Jason Heffernan, Chief officer at the Country Fire Authority told Guardian Australia that one house had been lost in the Briagolong region and a “significant number” of campers had been relocated.

“I anticipate we won’t see the Briagolong fire becoming contained until sometime tomorrow or the next couple of days,” he said. “It is quite large now – we’re estimating around 5000-plus hectares.”

Authorities have forecast the most destructive wildfire season during the approaching Southern Hemisphere summer in Australia’s populous southeast since the catastrophic Black Summer fires of 2019-20 that killed 33 people, destroyed more than 3000 homes and razed 47 million acres.

“We are in this run of very, very warm weather which hasn’t been seen in many, many years,” Australian Bureau of Meteorology’s senior meteorologist Miriam Bradbury said last month.

Authorities declared a “catastrophic” fire danger along the south coast of New South Wales, the highest level of danger in a five-tier rating system.

“The problem is when we get into fires in ‘catastrophic’ fire danger rating, there’s not much time for us to get on top of those fires and contain them and once they take hold we won’t be able to put those fires out,” Rural Fire Service Commissioner Rob Rogers said.

- Additional reporting, AP