Melbourne Airport and Flinders Street station experienced flooding after the deluge.

As torrential rain poured down steps to flood Flinders Street station, commuters were seen removing their shoes to walk through ankle-deep water and even climbing railing to escape the water.

More than 7000 homes were left without power, including about 5000 in Melbourne and 2000 in the Geelong area.

Some roads were turned into rivers after rain hit about 3.30pm.

Docklands recorded 33 millimetres of rain between 3.30pm and 5pm, while the CBD had 24 millimetres.

Melbourne Airport's international terminal, T2, was flooded after 32 millimetres of rain fell in just 30 minutes.

Airport spokesman Grant Smith said the deluge had affected some of the check-in counters.

"We would encourage everyone to make their way as safely as they can through the terminal and follow the directions of staff who are making sure that people can continue to check in for their flights," he said on Saturday.

"For anyone travelling domestically, we are suggesting that they get to the airport 20 minutes earlier than they otherwise might have, just to take in to account the conditions."

Drivers have been urged to take care on the roads after the "intense rainfall".

Bureau of Meteorology forecaster Michael Efron said there were a series of slow-moving storms over central Melbourne, extending over the inner-east and north-eastern suburbs and out towards Healesville and Lilydale.

"Because these storms are slow-moving, we have seen some pretty intense rainfall across inner suburbs of Melbourne," he said.

"For instance, the Melbourne station (at Olympic Park) has recorded around 10 millimetres in about 20 minutes.

"Around Docklands, there's been about seven millimetres in about 15 minutes."

City Road at Southbank was turned into a river with water lapping at vehicles' number plates, while a car became stuck in the York Street underpass.

Another car was destroyed when a man drove into floodwater under the Dudley Street rail bridge in West Melbourne.

"People should take care on the roads," Mr Efron said.

"There's some pretty intense rainfall out there which is reducing visibility in parts of Melbourne."

SES spokesman Kelvin Jewell said several trees had been downed across the state, causing traffic hazards.

"As little as 15 centimetres of water, which is about the size of an average pen, can be all that it takes for a car to lose traction and start to float," he said.

Victoria Police tweeted a warning to motorists to slow down amid reports of flash flooding.

Emergency crews were able to clean up quickly, however, with the SES reporting on Sunday that crews had a relatively quiet night.

No weather records were broken during Saturday's storms with the forecast looking a lot nicer for the rest of the weekend.

Sunday is expected to reach a maximum of 28 degrees after a low of 18, with a slight chance of a shower, or even a thunderstorm, in the afternoon.

Humid weather is set to continue for much of next week, reaching 29 degrees on Monday and 30 on Tuesday and Wednesday.

With Steve Lillebuen