NSW SES spokesman Andrew Richards said statewide there had been 2695 calls overnight, with the South Coast and Western Sydney among the hardest hit areas.

That brings the total number of calls since the rain began late last week to more than 10,000 across the state - and 775 in the Illawarra, Southern Highlands and South Coast.

"Most of the calls in the Illawarra region overnight were for trees and branches down and leaking roofs and other storm damage," he said.

"SES crews also had to help evacuate caravan parks on the banks of Lake Illawarra overnight which were subject to rising water, which was unable to drain away due to high seas and high tides.

"Roads were closed across the Illawarra too, including many in Albion Park, and we'd again reiterate to not drive through floodwaters - to turn around and find another way."

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Mr Richards said there'd been over 200 flood rescues across the state since late late week, and 111 overnight.

"A lot of the rescues were as a result of cars entering floodwaters," he said. "The weather is shifting further south, so we're asking people to be vigilant in those areas."

Mr Richards said in many areas including the Illawarra, people may only discover damage from the high winds and storms in the light of day or as waters receded.

"We're getting more calls in this morning and would ask people to be patient with us," he said. "Ring 132 500 for assistance."