Thousands of people in NSW and Victoria have been hit with electricity outages as damaging winds toppled trees and put power lines out of action.
A late spring cold burst moving over Australia's southeast has been to blame for cold temperatures, low snow, and damaging winds in multiple states, according to the Bureau of Meteorology.
A severe weather warning area covered parts of South Australia, Victoria, and the NSW and ACT on Monday, with meteorologists warning of gusts up to 100km/h.
Thousands of customers in NSW lost power as a result, with Endeavour Energy saying they were dealing with nearly 25,000 people whose supply was affected as of Monday afternoon.
The energy company pointed to wind gusts of 90 km/h as the cause of the outages. By Monday evening the number of people affected on their network had dropped to fewer than 4000.
A severe weather warning for damaging winds was issued on Monday afternoon from the Central Coast down to the Victorian border.
It included people in the metropolitan, Illawarra, South Coast, Southern Tablelands, South West Slopes, Snowy Mountains, Riverina, Hunter and Central West Slopes, and Plains forecast districts.
The bureau warned of wind gusts more than 90km/h, with a top gust of 104km/h recorded at Cabramurra in the Snowy Mountains.
The NSW State Emergency Service received nearly 750 requests for assistance in the 24 hours to 5pm on Monday, with nearly 300 of those for metropolitan Sydney.
The vast majority of calls involved trees falling down, spokesman Greg Nash said.
"It goes to show that saturated grounds and winds cause trees to fall down," he told AAP.
Forecasters observed wind gusts of 90km/h in parts of Melbourne on Monday, and the state's strongest gust was recorded as 130km/h at Wilsons Promontory in Victoria's southeast.
As of Monday evening, more than 15,500 people were without power across Victoria.
Winds were expected to moderate over inland areas into Monday evening, with the wind risk contracting to South Gippsland overnight.
As of 6.45pm on Monday, Victoria's State Emergency Service had fielded nearly 850 calls for help in about 12 hours.
Of those, nearly 730 were for fallen trees, and more than 100 requests for assistance were still active by 7pm.
While winds would ease from the west of Australia into Monday evening, elevated parts of NSW and Victoria remained at risk of damaging winds into Tuesday morning, the bureau said.