“It’s really important to avoid those flash flood hot spot areas - we all know where they are, they happen every single time it rains,” SES Illawarra/Shoalhaven deputy region controller Alex McFadden said.

“So, just be wary of where you’re going, take an alternate route to school or to work this morning and just make sure that you’re keeping aware of the situation.

“Don’t put yourself in floodwater - if it’s flooded, forget it.”

Illawarra SES crews responded to 80 calls for help in the 24 hours to 8.30am on Wednesday after heavy rain lashed parts of the region overnight.

Southern areas were the hardest hit, as a low pressure trough off the coast pushed rain across the region.

SES flood rescue teams responded to two incidents in the Shellharbour area - one on Shellharbour Road, near Sunset Avenue, where one person had to be rescued from a car after they became caught in floodwater.

In the other incident, crews were called to Station Road at Albion Park Rail but arrived to find no vehicle in the water.  

The nearby Illawarra Highway was closed due to flooding - and remains blocked on Wednesday morning.

A number of other roads in the Shellharbour area were closed on Tuesday night but have since reopened.

The majority of the SES calls for assistance – more than half –  were in the Shellharbour City Council area, while Kiama also copped a battering (20 calls).

The heavy rain first hit Kiama about 8pm, Ms McFadden said, with the majority of jobs related to leaking roofs.

“The large amount of calls we had last night [Tuesday] were for roof damage,” she said.

“The next highest number of jobs we had were related to flash-flood water that’s actually impacting on property and coming in through garages and front doors.”

Only a handful of jobs came from Wollongong, Coniston and Nowra.

Ms McFadden said the recent extended spell of warm weather could be attributed to many of the leaking roofs.

“What we find whilst we’ve had a long period of dry, hot weather is … things contract and expand with the heat, so it can cause cracks in roof construction,” she said.

“When we do have our first big downpour, the majority of people who think their roofs are perfectly fine actually find themselves in some difficult situations.”

7am: Parts of the Illawarra were drenched by more than 100 millimetres of rain overnight - much of it falling in just a few hours - and there’s more wet stuff on the way.

At Albion Park, flooding has closed the Illawarra Highway in both directions between the Princes Highway and Tongarra Road. The Princes Highway is being used as a diversion.

Other parts of Shellharbour which flooded on Tuesday night have been reopened.

Twenty millimetres fell in the 30 minutes to 9.30pm at Albion Park and Foxground, as heavy rain lashed southern parts of the region.

As of 6.30am, Albion Park had recorded 110mm, while Kiama had 86.6mm.

Falls were lighter further north, with 27.8mm registered at Bellambi.

A severe weather warning was issued by the Bureau of Meteorology on Tuesday night, but it has since been cancelled.

The Illawarra can expect a cloudy Wednesday, with a very-high chance of showers, becoming less likely this evening.

The bureau says locally heavy falls are again possible on Wednesday and there’s also the chance of a thunderstorm near the coast early during the morning.

More to come