Climatic conditions played havoc with the Australian Open again on Thursday as dust carried from the Outback coated the courts.

Heavy rain on Wednesday evening dumped the dust all over the city, with the Yarra river turning brown, and, when it cleared on Thursday morning, it became clear the Melbourne Park groundstaff had a lot of work to do.

Play started as scheduled on the three courts with roofs, which had all been covered, but it was delayed by three hours on most of the outside courts, and then further by more heavy rain.

Last week qualifying was disrupted by smoky haze from the wildfires and a thunderstorm that brought huge hailstones.

The start of main draw action on Monday, meanwhile, coincided with the wettest day in the city for nearly a decade.