The Bureau of Meteorology said strong winds in many areas along the east coast have made it feel even colder and below average maximum temperatures are expected to continue all week.
A low pressure system over the southeastern Tasman Sea is directing bitterly cold and blustery winds across NSW, with snow falling in the Central Tablelands towns of Blayney, Bathurst, Oberon and west of Lithgow, as well as the southern ranges.
Plummeting temperatures also brought snow to the nation's capital Canberra as ministers were sworn in on Wednesday.
Gusts of up to 124km/h were recorded on Hogan Island in Victoria and up to 119km/h at Cape Grim in Tasmania.
In NSW, Bellambi recorded gusts of 102km/h and Nowra 98km/h.
Saturated ground from the drenching NSW copped over the last few months brings an increased risk of gusting winds toppling trees and powerlines, particularly along elevated terrain.
The SES has responded to about 1400 calls for help since Monday with falling trees causing the greatest hazard.
A further 500 calls came on Wednesday, mostly in the Illawarra and South Coast regions.
"There a quite a few jobs outstanding and we're working with our partner agencies," an SES spokesperson told AAP on Wednesday evening.
"Our volunteers will be out in the freezing cold tonight making sure they can look after their communities."
Severe weather warnings for damaging winds have been withdrawn, however, there is still danger trees can topple.
Winds are expected to ease overnight into Thursday, but cold showery weather is forecast for the weekend.
The Perisher snowfields will open early this weekend after reporting 22cm of snow over the last six days.
Thredbo resort, set to open on June 11, has registered 19cm over the same period.
Mt Hotham also received significant snow and the strong winds have led to blizzard conditions in alpine areas, the BOM said on Wednesday.
The cold and snowy weather has prompted NSW Police to urge caution after two men were rescued in Kosciuszko National Park on Tuesday.
The two men aged 20 and 33 left on Sunday to climb Mt Kosciuszko but became disoriented on their return and took shelter at Seamans Hut.
They were found about 11am Tuesday after managing to contact emergency services.
The incident was a reminder to hikers to make sure they have the proper safety equipment and inform other people of their plans.
"Even the most capable hikers can get caught out, so please be mindful of changing weather conditions," NSW Police Superintendent John Klepczarek said.
The plummeting mercury comes after Sydney recorded its wettest autumn on record.
The state capital's 1008.4mm between March and May is the city's highest autumn total in records dating back to 1859, said Weatherzone meteorologist Ben Domensino.
The January-to-May period was also Sydney's wettest on record.
13°C