Flooding, traffic chaos as heavy rains lash Sydney

Flights were cancelled, railway lines closed and motorists stranded on flooded roads, as a month's worth of rain fell on Sydney early Wednesday, leaving emergency services battling to respond.

Severe thunderstorms and heavy rainfall lashed Australia's largest city, with the local Bureau of Meteorology reporting more than 106 millimetres of rain fell in some places within a few hours.

The city usually sees an average of 84 millimetres for the entire month of November.

One person was said to have died in a storm-related traffic accident and two police officers were injured by a falling tree while performing a rescue, including one female constable who sustained a broken leg.

The emergency services said they had carried out 12 flood rescues by mid-morning.

"The conditions we are experiencing today are some of the worst I've ever seen, and I am appealing to everyone, motorists and pedestrians alike, to take care," said assistant police commissioner Michael Corby.

The police urged residents to use caution and not drive vehicles into flooded roads, saying that a "major cause of death during floods is by people entering floodwater. Find an alternate route and avoid unnecessary travel." Electricity providers reported at least 6,600 people were left without power.

At the city's main international airport, multiple flights were cancelled or delayed and aircraft were left stranded on the tarmac as ground crews took shelter from the downpour and electrical storms.

"Due to adverse weather conditions today, we expect that International and Domestic terminals will experience some flight delays and cancellations," said the airport authority.

Rainfall was forecast to continue throughout the day and a flood warning was in effect for some minor rivers in the city.

Australia is no stranger to extreme weather, experiencing flash floods, sandstorms and even extreme drought in areas that are now being inundated.

Meanwhile in Queensland state to the north a dry spell fuelled bushfires that forced scores of people to flee their homes.