All of Australia’s mainland states, and the Northern Territory, had areas that reached more than 40C on Wednesday, as residents were warned it was too late to leave as two serious bushfires hit areas of South Australia.

Meanwhile, a code red bushfire warning – signifying the worst possible conditions – was issued for parts of Victoria for Thursday.

By 3pm AEDT on Wednesday, the highest temperatures recorded were 43.4C at Smithville in New South Wales and 42C at Walpepup in Victoria. Ballera in Queensland reached 43.7C, Warburton in WA got 43.8C, Nullarbor in South Australia recorded 46.6C and Lajamanu in the Northern Territory had hit 42.7C.

The Bureau of Meteorology said there had been multiple times when all mainland states had recorded temperatures of at least 40C. The record for the earliest date for such a record was 12 October 2004.

A pre-summer heatwave has Victoria ready for code red bushfire conditions in the north as well as a state-wide total fire ban on Thursday.

Overnight temperatures are forecast to stay at 30C and northerly winds will hit high speeds to put the Mallee and the Northern Country districts on a code red alert.

Residents in northern Victoria will swelter through temperatures over 40C, and Emergency Management Victoria recommended regional populations move to their nearest city centres.

Code red signals the worst possible bushfire conditions and the safest place to be is away from high risk fire areas within those districts, the CFA advised.

As a result of the predicted conditions, some schools and early childhood centres will be closed in some districts and community services may not be available.

All public parks in the Code Red areas will be closed.

Houses thought lost in SA

Houses and sheds are thought lost in a bushfire that was threatening lives on South Australia’s Yorke Peninsula. The fire started close to homes on Wednesday as the state sweltered through catastrophic conditions with soaring temperatures and high winds.

The loss of property was yet to be confirmed but there were reports at least two houses had been destroyed in an area home to about 1000 people. There were no immediate reports of any injuries with the fire burning mostly in stubble as conditions in the area continually changed.

In the latest emergency warning, the Country Fire Service urged everyone in Yorketown to take shelter as it was no longer safe to leave. This fire was burning in a northwesterly direction towards Waterloo Bay and Wattle Point.

An emergency warning was also declared for another fire on Yorke Peninsula with the blaze at Price flaring after initially being downgraded. It was subsequently downgraded again but authorities warned it was still to be contained.

They were among more than 40 fires across SA, including two others north of Adelaide and one in the Barossa Valley which also sparked emergency warnings at one stage.

CFS deputy chief officer Rob Sandford said the efforts of firefighters across the state on Wednesday had been outstanding.

“The work crews have done to halt these fire has been nothing short of amazing,” he said.

The fires across SA came as the state sweltered through record-breaking temperatures with many regional centres posting their hottest November day.

Adelaide fell short with a top of 42.2C at the Bureau of Meteorology’s Kent Town observatory – just shy of the record 42.7C recorded there in 1962.

Those conditions also prompted SA Power Networks to cut electricity to more than 10,000 properties on the lower Eyre Peninsula amid safety concerns.

“With fire conditions expected to continue well into this evening, be prepared for a potentially extended outage before it is safe to restore power supply,” the company said.

A cool change was expected to sweep across the state by early Thursday but the CFS warned the dangerous conditions would linger.

The bureau issued a severe weather warning for potentially damaging winds across a wide area including most of the York and Eyre Peninsulas and the Adelaide Hills.

It said wind gusts of up to 90km/h were possible as the front moved through.

Thursday to bring difficult conditions in NSW

NSW is facing widespread severe bushfire danger as predicted hot winds blowing in from the south present yet more challenging conditions for firefighters.

Rural Fire Service NSW Commissioner Shane Fitzsimmons said a weather system coming in from South Australia will bring hot easterly winds on Thursday.

“We know over the coming days, particularly tomorrow, we’re expecting again widespread very high to severe conditions,” Fitzsimmons told ABC TV.

“This time, the indications are [it will be] the southern half of NSW with some of the more widespread, worst conditions. We’ve got a long way to go yet.”

There are 12 total fire bans in place across the state.

A severe fire danger rating is in place for 10 areas, including Illawarra/Shoalhaven, North Western and the Southern Riverina.

Most fires were at advice level on Wednesday evening. However, alerts were elevated to watch and act for a near-20,000 hectare blaze at Ebor near Armidale, and a bushfire at Myall Creek Road in Bora Ridge, southeast of Casino which has consumed more than 30,000 hectares.

There were 50 fires across NSW on Wednesday afternoon, 24 of which were uncontained. More than 1000 firefighters remain in the field.

Sydney’s air quality, which has deteriorated in a smoky haze in recent days, is unlikely to improve anytime soon as the fires continue, the Bureau of Meteorology said.

There are also concerns that weekend thunderstorms, which won’t bring much rain, could see lightning strikes ignite additional fires.

Six lives and 577 homes have been lost to date this fire season, with more than 420 homes lost in the past fortnight.

Tasmanians told to prepare for dangerous conditions

Tasmanians are also being told to prepare for the most dangerous fire conditions so far this bushfire season, with high temperatures and strong winds to hit the state.

The fire danger rating in the south and southeast will reach severe levels on Thursday, the Tasmania Fire Service has warned.

Temperatures are forecast to peak in the mid-30s across the island, with Hobart expected to reach 30C.

“These are the most dangerous fire weather conditions forecast so far this bushfire season and any fires that start will be difficult to control,” deputy chief officer Bruce Byatt said on Wednesday.

A 24-hour total fire ban has been declared for the north and south from 2am on Thursday, with landowners told to put out any fires before then.

Dry winds of 60-70km/h are forecast, but relief from the hot weather is expected on Thursday afternoon when a cold front crosses the state.