The calendar may not have ticked over yet, but the wintry weather has arrived — and forecasters say the frosty conditions are far from over.
Large parts of southern-eastern Australia were plunged into freezing conditions on the weekend, as icy air from Antarctica was pushed across the eastern states by a strong cold front.
The strong winds disrupted flights in Sydney, while people from New South Wales, Victoria, the ACT and Tasmania took to social media to share photos of the swathes of hail and snow blanketing the streets and mountain tops.
And while the wet weather may have eased, the Bureau of Meteorology has warned the cold conditions are far from over with all states, except for Western Australia, expected to receive below-average temperatures on Monday and Tuesday.
So just how cold did it get and what's in store over coming days?
Record cold for NSW, ACT
Across New South Wales temperatures were between 4 and 8 degrees Celsius cooler than usual on Sunday, with hail falling across large parts of the state.
It was particularly cool in the state's south-east, with some towns breaking May temperature records.
Cooma reached 2.7C on Sunday, its coldest May maximum on record, while Canberra peaked at just 7.8C, its coldest May day in more than 20 years.
Many inland areas were hit with minimum temperatures below zero on Monday morning, including Bathurst, Orange and Cobar.
As the temperature plunged there was also precipitation, resulting in the first decent snow of the year for the alpine regions.
Bureau of Meteorology senior forecaster Dean Narramore said snow fell to 700 metres including a "few centimetres" outside of the alpine areas in places such as Jindabyne, Cooma and Oberon.
The snowy mountains, ACT and central tablelands were covered by 10 to 20 centimetres of snow just weeks out from the official ski seasons, as Thredbo fell to -7C.
"Sometimes, the 'feels-like temperature' there felt like minus 20C," Mr Narramore said.
In Sydney, the mercury fell to 7.1C on Monday morning with dozens of flights cancelled or delayed at Sydney Airport due to the strong winds.
The airport had been operating with just one runway since Sunday night.
An Airservices Australia spokesperson said crosswinds on the parallel runways had reached 30 knots.
"This decision is purely weather-related," the spokesperson said.
The airport returned to normal operations early Monday afternoon, but some flight delays are still likely as the airport deals with the backlog.
Deep snowfall across Victoria's alpine region
Victoria was also cold and snowy across much of the state.
In the Yarra Valley, Mount Donna Buang recorded about 15cm of snow, with 10 to 20cm of snow also falling at Mount Buller and Mount Hotham over the weekend.
The cold extended right across the state with some of the chilliest morning temperatures recorded on Monday morning.
Rutherglen fell to –2C while parts of the Wimmera and south-west regions hit zero.
"Much of south-eastern Australia had their coldest temperatures so far this year, and for some their coldest since last winter," Mr Narramore said.
Widespread frost for Tasmania
For Tasmania, Sunday and Monday were the coldest days with widespread frost across the state.
Parts of the central plateau dropped to –7C on Sunday morning, with snow falling on kunanyi/Mount Wellington and some of the higher terrain.
Mr Narramore said the southernmost state had received a few centimetres of snow rather than the 10 to 20 cm in New South Wales and Victoria.
Fingal, in the state's north-east fell to –4C on Monday morning.
While Launceston dropped to –2.5C Monday morning, well below its average minimum temperature of 5.1C in May.
Antarctic air to reach almost all of Australia
The rain, snow and hail conditions have now eased.
But there is plenty more cold weather to come with the cold air from Antarctica expected to reach the northern parts of Queensland and the Northern Territory on Monday and Tuesday, according to the BOM's forecast.
Mr Narramore said the cool conditions would spread across the entire country except for Western Australia.
"The low pressure system off New South Wales will maintain cold and chilly conditions right across the country on Monday," he said.
"And Tuesday morning we could see widespread frosts through southern inland areas of Queensland and once again parts of inland New South Wales, Victoria and Tasmania."
Large and hazardous swell is also forecast across a large part of the New South Wales' coast from Newcastle to the Victorian border.
Mr Narramore said swells of 5 to 6 metres were forecast with a warning of possible erosion.
