Sydney has been lashed with "phenomenally heavy" rainfall, as a bank of thunderstorms rolled across the city, causing flash flooding and trapping people in their cars.
The storms moved in from the south and southwest from about 9pm on Sunday, dumping as much as 26mm of rain in 10 minutes in some places, the NSW Bureau of Meteorology (BoM) said on Monday.
It caused severe flash flooding in low-lying areas in the south of the city, trapping up to eight people in their cars in Waterloo, the State Emergency Service (SES) said.
About 11 other flood rescues took place in cars at suburbs that included Alexandria, Zetland, Rosebery, Mortdale, Gymea and Darlington, SES spokesman Phil Campbell said.
The SES received 300 calls for assistance, he said.
BoM duty forecaster Chris Webb said most areas saw heavy rainfall for no more than an hour.
"It was only brief, but it was phenomenally heavy," Mr Webb told AAP.
Peakhurst saw 26mm in just 10 minutes and 75mm in one hour, while Terrey Hills saw 69mm of rain in less than an hour.
The storms have moved to the northeast of the state, with some isolated storms expected over the central tablelands and Blue Mountains.
"One or two of these may hit western Sydney," Mr Webb said.
However, Sydney city was unlikely to see much more rain throughout Monday, apart from a couple of isolated showers in the afternoon, he said.
A Sydney airport spokeswoman said several flights were delayed due to flooding.
Flights were delayed for between an hour and 90 minutes on Sunday evening after flash flooding hit the airport.
Seven News reported a car park in Terminal 2 had been inundated, with several cars flooded.
The spokeswoman said there no delays on Monday morning.
"It's business as usual today," she said.
