It's a white Christmas in the heart of summer in Australia's southernmost state, as snow falls in elevated parts of Tasmania this Thursday, December 25, 2025.
Snow is falling as low as 700 metres above sea level on Christmas morning, meaning that the summit of 1271m kunanyi/Mt Wellington above Hobart is receiving its fair share of snowflakes.
This Christmas morning snowfalls are a continuation of a Tasmanian cold outbreak that started late on Tuesday and continued through Wednesday.
You can see the moisture-laden airmass responsible for the Christmas morning snowfalls surging towards Tasmania and coastal parts of the SE mainland in the loop below. The speckled cloud pattern is typically associated with airmasses with polar origins.
Image: Four-hour combined satellite and radar loop over Tasmania on the morning of Thursday, December 25, 2025.
Why is it snowing in the Australian summer?
Summer snow is far from a rare event in the highest parts of Tasmania and Australia's southeast mainland, and tends to occur at least once each summer.
Indeed, Tasmania saw snow a week ago even as bushfires burned in the state’s east, while snow was reported at the mainland ski resorts on December 1.
Even in Australia's warmest and driest year on record in 2019, heavy snow fell on the mainland high country in December.
Image: A slightly blurred image due to the Christmas Day snowflakes sticking to the screen at the Mt Mawson shelter, Tasmania, on Thursday, December 25, 2025. Source: Mt Mawson.
While the cold fronts that circulate the Southern Ocean tend to slip southwards during the Australian summer, the occasional pool of unstable polar air is always a chance to push northwards at this time of year.
That’s what has happened this week, and it’s largely thanks to the jet stream – the swift-moving "river" of air high in the atmosphere which generally blows from west to east.
The jet stream tends to move in waves in what is known a meridional pattern, sharply dipping to the north and south as it moves east. This week, the meridional pattern has allowed cold air to be dragged up over Tasmania.