Oodnadatta in South Australia is forecasted to reach 45°C on Monday, while Birdsville in Queensland is expected to endure over five days of temperatures exceeding 40°C, highlighting the severity of the heat event.

Wednesday is predicted to be particularly hot, with Sydney expected to reach 38°C and potential record-breaking temperatures in other towns like Lightning Ridge, Bathurst, and Orange.

A significant heatwave is impacting Australia, with temperatures soaring approximately 12°C above average across South Australia, south-west Queensland, and western New South Wales, pushing some locations close to October temperature records.

While a three-day heatwave is unlikely in Sydney, parts of the Northern Territory, Queensland, and northern New South Wales may experience well above-average temperatures, increasing heat-related risks.

The extreme heat is accompanied by high fire danger across Western Australia, Queensland, northern South Australia, and New South Wales, with parts of the Illawarra, Sydney metropolitan area, and Hunter facing extreme fire risks due to hot, windy, and dry conditions.

Adding to the weather volatility, severe thunderstorms with the potential for giant hail are forecasted for Saturday in south-east Queensland and north-east New South Wales.

Over the weekend, new October temperature records were set in Western Australia, with Telfer reaching 44.3°C and Warburton 43.9°C, as well as in South Australia, where Ernabella hit 40.9°C and Tarcoola 43.9°C.

Since 1910, Australia's land surface has warmed by 1.5°C, a change linked to climate change that has increased the frequency and severity of extreme weather events.