Arctic blast: Tasmania blanketed in snow as cold snap hits south-east Australia

South-east Australia is set to shiver through a winter cold-snap this week, with some areas experiencing sub-zero temperatures and others up to 8C below average .

Parts of Hobart woke to streets blanketed in white on Monday morning after the flurry overnight, with snow levels pushed down to 300 metres.

The low level snow has prompted a bushwalkers and road weather alert for large parts of Tasmania amid frosty roads and possible black ice.

The frigid air mass has brought Arctic temperatures that will stay for the remainder of the week.

On the weekend, winds of up to 107 km/h were reported at Mt Buller on Saturday, while St Kilda harbour was lashed with 83 km/h winds.

In the ACT, minimum temperatures were forecast to drop below zero from Tuesday morning onwards, with morning frost.

While flooding in New South Wales has eased, showers were forecast to return on Tuesday and linger all week in large parts of the state including Sydney, where there was more than a 90% chance of showers from Tuesday through to Sunday.

Sydney was already having its wettest July on record. As of 15 July, it had recorded about 340mm of rainfall, more than three times the monthly average.

It took just a fortnight to break the previously held 1950 record of 336.1mm.

Bradbury said snow levels in Victoria and southern alpine NSW would remain at about 800 metres into early Tuesday when conditions lifted.

Four flood warnings were still active across NSW for the Macquarie, Bogan, Lachlan and Darling rivers.

The Bogan River at Nyngan was expected to peak near 3.7 metres on Tuesday morning, with moderate flooding, while moderate flooding was also possible along the lower Bogan River at Mulgawarrina towards the end of the week.