These temperatures are well below average, even for the middle of winter.

So why is it so cold? And how long is the chill going to last?

An Antarctic blast

Much of southeastern Australia is currently under a cold air mass that has come from the south.

This is because a low pressure system that brought heavy rain, strong winds, and even a possible tornado to South Australia, has moved eastwards.

Air moves clockwise around low pressure systems in the Southern Hemisphere, so low pressure over Tasmania and the Tasman Sea means we have strong southerly and south-westerly winds over Victoria and New South Wales.

As the low pressure moves east, cold fronts and troughs have crossed the region. This has led to most of southeast Australia experiencing rain or snow.

While a high pressure system briefly dominates our weather on Thursday, a new low brings cold and wet conditions again through the weekend. Another cold front is forecast to cross Tasmania, Victoria and southern New South Wales on Friday night.