Perth has sweltered through its hottest night on record, a portent of the extreme conditions that will pose a health risk across the southern states over the next week.
Temperatures in Perth peaked at more than 43C on Saturday, and dipped to a still-steamy low of 29.7 just after 3am on Sunday.
That beat the previous record of 29.3 in 1962. The mercury rose again to 39.7 in the city just after 9am.
In Victoria, the bureau has forecast three days of more than 40 – Tuesday, Thursday and Friday – with no relief until Saturday. The temperatures for the first five days of the Australian Open, starting on Monday, are tipped to be 35, 41, 39, 41 and 40.
The southern capitals will also experience sweltering nights. The minimum temperature predicted for Friday for both Melbourne and Adelaide is 28.
In South Australia, nurses will increase their checks on vulnerable people in the community as temperatures soar.
“Apart from the extreme coastal locations, you really could get a 45C-type maximum anywhere,” said senior forecaster Tom Boeck.
The State Emergency Service issued an extreme heat warning on Sunday and says hot weather conditions from Monday to Friday might be a risk to public safety.
Premier Jay Weatherill said people needed to revisit bushfire action plans and be prepared for an emergency.
“With several days forecast to be over 40 degrees, fire danger will be incredibly high, so it’s important people have plans in place to deal with an emergency,” he said.
Fire authorities will be on high alert, and police are expected to instigate Operation Nomad patrols, which check on known firebugs.