A wave of summery heat moving across southeastern Australia brought a very warm Saturday, with another hot day on Sunday for Australia’s southeastern capitals.

Adelaide and Melbourne record hottest day of spring on Saturday

The burst of summer sweeping across southeastern Australia brought the warmest day of spring to both Adelaide and Melbourne yesterday. 

Adelaide reached a maximum of 26.5°C on Saturday, making it the hottest day since last autumn. The average maximum temperature in Adelaide during September is 18.5°C, 8 degrees below yesterday’s maximum.

In Melbourne, the mercury reached 26.9°C yesterday, making it the warmest September day since 2023. This was nearly 10 degrees warmer than the average September maximum temperature in Melbourne of 17.3°C.

Image: Melbourne Observation History showing yesterday’s very warm day, and current conditions as of midday, as seen on the Weatherzone App.

In the east, Sydney reached a maximum temperature of 31.0°C, which fell short of the 32.1°C experienced earlier this month on Saturday, September 5, as dry, blustery winds drove record heat across Sydney.

Another day of heat for Melbourne and Sydney

As seen in the image below, maximum temperatures across southeastern Australia are once again very warm this Sunday. Melbourne is forecast to reach 27°C, while Sydney has already reached 28.4°C just after 11am. 

Image: Forecast maximum temperatures across southeastern Australia on Sunday, September 20, 2026. Source: Weatherzone.

A cold front has already swept into Adelaide, limiting another day of heat, and will bring an end to this spell of heat later this afternoon for Melbourne, and in the late morning tomorrow for Sydney.