Parts of southeastern Australia just had their coldest morning in more than a decade, with the mercury reaching -10 degrees in some areas.

The combination of a very cold air mass, clear skies, and light winds provided the ideal conditions for temperatures to plummet in Victoria and NSW on Wednesday night.

Image: Infrared satellite image and observed surface temperatures at 6:30am AEST on Thursday.

By Thursday morning, parts of both states were experiencing their lowest temperatures in several years. A few locations even registered their coldest morning in more than a decade.

The lowest temperature in the country on Thursday morning was -9.7 degrees at Glen Innes in northern NSW. This was the 2nd lowest temperature in Australia so far this year, behind -10.2 degrees at Liawenee in Tasmania on August 4th.

Image: Frost in Young, NSW on Thursday morning. Source: @treasures_at_derrymore / Instagram

Other notable lows in NSW included -9.3 degrees at Thredbo Top Station and -8.7 degrees at Perisher. Outside the alps, Singleton (0.2C) had its coldest morning in three years, while Gunnedah (-5.2C), West Wyalong (-2.8C), Griffith (-4C), and Deniliquin (-3.4C) all registered their lowest temperature in two years.

Image: A wintry start in Orange, NSW on Thursday morning. Source: @yamba_angus / Instagram

In Victoria, Hopetoun (-5.3C) and Nhill (-3.0) both experienced their coldest morning since 2006 and Rutherglen (-4.8C) had its coldest in two years.

The next few nights will be a bit warmer in NSW and Victoria as a low pressure system causes clouds, rain, and wind to increase over southeastern Australia. However, days are going to be very cold as the cloud and rain limits surface heating from the sun.  Some places are forecast to have maximum temperatures around 10 degrees cooler than usual for this time of year in the coming days.