Eastern Australia will continue to shiver through unusually cold temperatures for the rest of the week, with some capitals facing their coldest morning of the year so far, as the country’s weather pattern gets “stuck in the mud”.

The prolonged cold snap comes just days out from the winter solstice — the shortest day of the year. 

A jogger enjoys the first rays of sunshine on frost-covered meadows at the Jerrabomberra Wetlands in Canberra at minus 4 degrees Celsius last Sunday.(Supplied: Ainsley Morthorpe)

Over the weekend and into Monday, early morning temperatures fell to sub-zero levels across six states and territories, from Tasmania to Queensland.

Daytime temperatures also struggled to warm up, with some parts of Victoria and South Australia experiencing their coldest June day in over 20 years during the weekend, according to the Bureau of Meteorology (BOM).

June records in Victoria and South Australia
  • 8.1C Horsham, Vic. Lowest June max on record (27 years)
  • 8.3C Hopetoun, Vic. Lowest June max on record (21 years)
  • 8.3C Nhill, Vic. Lowest June max on record (22 years)
  • 8.3C Charlton, Vic. Lowest June max on record (20 years)
  • 10.1C, Robe, SA. Lowest June max on record (21 years)

BOM senior forecaster Angus Hines said the frigid morning temperatures with clear, cool days were showing no signs of letting up, in what was proving to be an unusually long cold snap. 

“It’s quite a long time, actually,” he said. 

“We’ve had a chilly weekend, but the weather pattern is going to keep feeding in those chilly conditions through most of the rest of this week.”

Tuesday and Wednesday are expected to be the worst, with widespread areas of morning frost forecast for Tasmania, Victoria, New South Wales, and the ACT.

Queensland hit hardest by cold snap

Mr Hines said in particular places in eastern Queensland could be facing overnight minimum temperatures up to 10 degrees below average on Tuesday and Wednesday.

Wednesday morning minimum temperatures will be particularly cold across eastern Australia.(Supplied: BOM)

“We’re not forecasting any places to get their all-time records, it’s very rare that you do forecast that,” he said.

“But there are a few places we’ll be keeping a particularly close eye on … where the colder air is going to keep temperatures down in the single digits, or even toward zero, at places that rarely see that.”

This included Proserpine, in the Whitsundays region of Queensland, which was forecast to fall to 4C on Wednesday morning –  well below its average low of 12.9C, while Mackay was forecast to fall to 7C, also well below its normal.

Widespread frost is forecast from Tasmania to central Queensland on Tuesday and Wednesday.(Supplied: Ainsley Morthorpe)

Meanwhile Tasmania, Victoria, New South Wales and the ACT are forecast to get minimum temperatures broadly between 2C and 5C colder than normal for the rest of the week – something Mr Hines said was bound to be noticed given it was approaching the coldest time of year.

Melbourne and Sydney are both forecast to have their coldest morning of the year on Wednesday, with minimums of 2C and 6C, respectively.

Weather pattern ‘stuck in the mud’

Mr Hines said the cold weather was being caused by a low-pressure system sitting halfway between New Zealand and Australia, directing a stream of icy winds over the continent.

This is a typical feature to see during winter in Australia.

But in this case, it’s been unusually slow to move on, according to Mr Hines.

“This one is stuck in the mud,” he said.

“It’s not really moving anywhere over the next five days or so, continuing to steer that wind from the Southern Ocean up and over eastern Australia.”

Australia has seen several slow-moving weather patterns already this year, with the month of May dominated by “blocking highs” – another type of weather system — which led to a record run of unseasonable warmth across Western Australia, and a long spell of showery days for parts of the eastern seaboard.

Rain and gusty winds for WA and SA

In Western Australia and South Australia temperatures are tracking closer to normal, however Mr Hines said there was some much-needed rain on the horizon.

Both states have been dealing with extremely dry conditions this year, which have led to critical water shortages in some parts.

Mr Hines said during Tuesday and Wednesday a cloud band would continue to deliver unseasonal rainfall to a pocket of WA’s north-west — through the northern Gascoyne and western Pilbara, potentially up to 100mm over three days.

Then during the afternoon, a cold front was forecast to graze the south-west corner of WA.

He said this was forecast to bring showers to the area and some gusty winds on Tuesday, though it would mostly be on the lighter end.

By Wednesday, however, he said the falls would ramp up as the system made its way into South Australia, with a low-pressure system becoming embedded within it.

Mr Hines said falls of 15 to 30mm were possible across southern parts of the state, from the Eyre Peninsula to Adelaide and the south-east, with the potential for localised flash flooding in some areas.

“But by and large, it’s a good news story, with rain hitting parts of the country that do want rain, even if it comes in quite heavy for some.”

He said some of that rainfall was forecast to spill across to northern Victoria and New South Wales on Thursday into early Friday, bringing a “brief” spell of rain and potentially some snow.