Drivers are being urged to take care on the roads this morning, with overnight storms causing multiple issues across the state.

Multiple sets of lights are out across Melbourne and Geelong, with flash flooding also closing lanes on the Ring Road, Altona-bound.

And anybody heading to NSW from Melbourne will face a significant detour.

The Hume Freeway is closed between Benalla and Chiltern due to flooding.

The Murray Valley Highway is also closed between the Hume Freeway and Rutherglen.

A severe thunderstorm warning has been issued for Hastings, Western Port, Cowes and Phillip Island.

A flash flooding warning has also been issued for Mount Martha, Mornington, Hastings and Dromana.