Tasmania just registered one of its coldest autumn mornings on record as a thin layer of icy air became trapped over the state’s interior thanks to a strong temperature inversion.

Clear skies and light winds developed over Tasmania on Monday night under the centre of a slow-moving high pressure system.

These clear and calm conditions allowed the ground to cool steadily overnight, as heat from the previous day radiated up towards space. This efficient and constant radiative cooling allowed a thin layer of very cold air to develop near the ground. As temperatures plunged, fog could be seen oozing through valleys and across lakes in the state’s central highlands.

Video: Satellite imagery showing fog sitting in valleys across Tasmania on Monday morning, slowly clearing as temperatures rose through the morning.

By the early hours of Tuesday morning, temperatures were near or below zero degrees at most of the weather stations in central Tasmania.

The state’s lowest officially recorded temperature on Tuesday morning was -9.9ºC at Liawenee, which occurred at 7:20am. This was the lowest autumn temperature observed anywhere in Tasmania since 2010. It was also the state’s third lowest autumn temperature on record.

Hobart was kept much warmer on Monday night by a layer of cloud drifting over southeast Tasmania, with the city only cooling to a low of 6.8ºC at 8:15am.

Tasmania’s lowest autumn temperature on record is -10.5ºC at Liawenee on May 30, 2006. The national autumn record is -13.4ºC at Charlotte Pass in NSW on May 24, 2008.