The intense heatwave currently baking parts (or in some cases all) of every Australian state and territory has just delivered the nation’s highest temperature in almost two years.

Just after 4:30pm (ACDT), the coastal South Australian town of Ceduna registered 49.5°C. This was:

• The hottest temperature ever recorded in the popular fishing and tourist town in records going back to 1939.
• The hottest temperature recorded anywhere in South Australia since 2019 when Nullarbor, about 300 km west of Ceduna, reached 49.9°C in December.
• Possibly the equal-highest temperature ever recorded at a location directly on Australia’s southern coastline (along with 49.5°C at Port Augusta in SA in January 2019), although there are no official records for that statistic.

Meanwhile Adelaide hit 44.7°C on its hottest day of what has been a very hot start to 2026, with four days this month now reaching 42°C or higher. 

Image: The famous Ceduna jetty on a somewhat more benign day.

Why was Australia Day so hot in a coastal location?

South Australia's coastline is no stranger to extreme heat. Before Australia Day 2026, Ceduna's previous high mark was 48.9°C.

That said, you tend to think of SA’s dry interior when you think of the hottest days. For example, the outback town of Oodnadatta, in the North East Pastoral forecast district, jointly holds Australia’s high temperature record of 50.7°C.

But this Australia Day, the core of the heat (the hottest air) was just northwest of Ceduna, and the winds took care of the rest.

"North to northwesterly winds were gusty enough and skies were sunny enough to take that temperature close to the coast,” Weatherzone meteorologist Brett Dutschke explains.

"Nullarbor, the nearest official weather station to Ceduna's west, picked up a sea breeze instead of the norhwesterlies so it only reached the high 30s."

While Ceduna can expect a cool change from the west overnight with a relieving maximum of 27°C on Tuesday, eastern and northern parts of South Australia can expect the extreme heat to continue.

After maximums of 46.9°C, 48.5°C and 47.2°C across the Australia Day long weekend, Oodnadatta is expecting 46°C, 46°C, 49°C, 49°C and 47°C from Tuesday through to Saturday.

And South Australia is not the only place likely to see 49 degrees this week.

Victoria to endure extreme heat on Tuesday

Image: Forecast Victorian maximums for Tuesday, January 27, according to the ECMWF model.

Victoria has never recorded a 49-degree day, in data extending back more than a century at many locations.

But numerous Victorian towns are forecast to hit 49°C on Tuesday, including Mildura and Ouyen. There are even indications that some nearby spots could nudge 50°C, including the small town of Hopetoun, south of Mildura, which holds the current state record of 48.8°C.

As you’d expect, Tuesday has been declared a day of total fire bans across Victoria, with extreme fire danger in most districts.

Melbourne is heading for a top of 45°C. The city’s hottest day on record was 46.4°C on the infamous "Black Saturday" of February 7, 2009.