Spring freeze sends temperatures below zero across five states

A spring chill is gripping southeastern Australia this week, with temperatures dropping below zero degrees in five states and territories on Thursday morning.

A cold and dry air mass combined with relatively light winds and clear skies over southeastern Australia on Wednesday night. This combination allowed for efficient radiative cooling near the surface, which caused temperatures to plummet. By the early hours of Thursday morning, temperatures had dropped to around -7°C in parts of New South Wales and -5°C in Victoria.

Parts of NSW, Victoria, the ACT, Tasmania and SA registered temperatures lower than 0°C on Thursday morning. The coldest place in the country was -6.9°C at Goulburn Airport in NSW, which was Goulburn’s lowest spring temperature since September 2017.

Modelled minimum temperatures on Thursday, September 17, 2026
Image: Lowest minimum temperatures in NSW, Vic, ACT, Tas and SA on Thursday, September 17, 2026. Source: Weatherzone.

While winds were light enough for frost to form over a broad area of Australia's southeast mainland on Wednesday night into Thursday morning, conditions were cloudier and windier in Tas and coastal areas of Vic and NSW.

Wind gusts reached close to 100 km/h in exposed areas of southwest Tasmania on Thursday morning, with the weather station at Maatsuyker Island clocking a 98 km/h gust shortly after 9:30am.

In Sydney, winds gusting at around 30 to 40 km/h on Thursday morning made the temperature feel like 2.5°C at 6 am and still only 5°C by 8 am – a wintry shock for any underdressed commuters.

Image: Canberra observations since midnight in the Weatherzone app, as of 11:50 am AEST on Thursday, September 17, 2026. Source: Weatherzone.

Some of the cold air that sent shivers across southeastern Australia on Thursday morning even reached northern Queensland. Cairns registered a minimum temperature of 12.4°C early Thursday, which was around 6°C below average and its lowest spring temperature since September 2019.

Minimum temperatures will increase over the next few mornings as warmer air returns to southeastern Australia on the western flank of a high pressure system. This change in air masses will also cause days to become increasingly warmer, with some areas in the country’s southeast likely to have their warmest days in four-to-five months this weekend.