Torrential rain hit Sydney on Thursday, causing minor flooding and transport chaos in the city, local media reported.

The Bureau of Meteorology said about 119 millimeters of rain fell on parts of the Sydney central business district (CBD) on Thursday morning.

"There has been very, very heavy rain and some very strong winds," a Bureau of Meteorology spokesman told the Australian Associated Press (AAP).

The heavy rainfall sparked widespread flash flooding, bringing the city's train services to a halt and causing the closure of dozens of roads in Sydney.

Wet and wild weather also caused power outages to about 300 homes in the city.

More than 20 residents of Austral in southwest Sydney were evacuated after a local creek flooded.

At the suburb of Marrickville in Sydney's inner west, 20 homes in three streets were evacuated on Thursday morning due to severe flash flooding.

Motorists were rescued from cars caught in flooding in several suburbs of Sydney.

Flights from Sydney Airport were delayed or canceled because of strong winds and rain.

Some railway lines in Sydney were suspended on Thursday morning due to flooding on the tracks. Commuters suffered major delays.

The New South Wales Fire and Rescue said 250 firefighters from more than 50 fire stations responded to dozens of incidents caused by the heavy rain across Sydney.