With an overnight minimum of a bone-chilling -13.2°C, Thredbo Top Station just registered Australia's coldest night of 2025 to date by more than three degrees.

It was the coldest temperature recorded anywhere in New South Wales since 2018, and the coldest in Australia since -13.5°C was recorded in the tiny town of Liawenee on Tasmanian’s Central Plateau on the morning of July 4, 2024 – a record for both the site and the state.

The coldest temperatures recorded overnight in Australia's eight states and territories were:

• NSW -13.2°C at Thredbo Top Station
• VIC -7.6°C at Mount Hotham
• ACT -6.1°C in Canberra
• QLD -4.3°C at Applethorpe on the Granite Belt
• TAS -4.2°C at Ouse in the Upper Derwent Valley
• SA -0.1°C at Keith West in the Upper South East forecast district
• NT 1.4°C at Alice Springs Airport
• WA 2.4°C at Forrest in the Eucla forecast district

Why was it so cold in eastern Australia last night?

A very dry polar airmass is sitting over southeastern Australia, with clear skies enabling considerable radiational cooling (where the Earth radiates heat away from the surface).

In the case of Thredbo Top Station – which is Australia's highest weather station sitting at an exposed site at an elevation of 1957m – a rare windless winter night contributed heavily to the frigid temperatures, with conditions completely calm for much of the night and early morning.

Image: Location of Thredbo Top Station AWS (automated weather station) as captured on the Thredbo snow cams on the morning of Monday, August 18, 2025. Source: Thredbo.

A third factor also helped the extreme chill develop at Thredbo Top Station, namely fresh snow.

A moderate snowfall of around 10cm occurred on the weekend. As Weatherzone meteorologist Tim Woebbeking explains, fresh dry snow acts as insulation, keeping ground heat from convecting upwards.

"It’s like a big puffer jacket for the ground that prevents heat being transferred to the near-surface air," Woebbeking said.

Meanwhile Thredbo Top Station can expect a comparatively balmy maximum of -1°C this Monday after its severe overnight low. A gradual warming trend will then set in for much of the working week, with overnight temperatures falling well below zero but unlikely to match Monday morning’s reading.

Remember to check the Weatherzone snow page throughout the 2025 Australian snow season for the latest forecasts, cams, and much more.