The repair bill for damage caused by a "catastrophic" hailstorm that struck Sydney and other parts of NSW is expected to exceed $125 million.
More than 25,000 people have lodged claims so far, the Insurance Council of Australia said on Friday, with three quarters relating to motor vehicle damage.
Many homes and businesses suffered damage to roofs, awnings and solar panels while overflowing gutters caused interior damage to some properties, the council said after declaring the storm a "catastrophe".
It expects the number of claims to rise sharply over the coming days.
Tennis ball-sized hailstones smashed into homes and cars in Sydney's west around 5pm on Thursday, while golf ball-sized stones battered the city's inner suburbs less than an hour later.
Windshields were smashed, roofs damaged and both cars and homes impacted by flash flooding.
NSW SES received calls to about 1800 jobs throughout the night with more than 500 volunteers responding.
"We've had lots of jobs so far where the house is uninhabitable with several rooms and ceilings collapsing," spokesman Christopher Mawn told reporters on Friday.
"We were just recovering from a previous storm cell as well, so we had outstanding jobs from there. It's been a busy few weeks for SES."
The Bureau of Meteorology called it the "worst hailstorm in 20 years." Hailstones with a diameter of five to eight centimetres fell in Berowra, Casula and Liverpool.
"While hail of this size is uncommon, we do see a lot of storms over the summer due to higher daytime temperatures," bureau forecaster Craig Ryan told AAP.
Mr Ryan said the wild weather would clear over the coming days.
Endeavour Energy on Friday afternoon said thousands of homes were still without power.
