An Australian Open that has been hit by weather extremes faced a new challenge on Thursday: dirty rain, after overnight downpours left courts muddy and unplayable.

Workers armed with squeegees and high-pressure hoses rushed to clean the surfaces, delaying matches on most of the courts.

The dirty rain, blamed on smoke hanging in the air from Australia’s raging bushfires, is just the latest hazard at a tournament that has been beset by meteorological mishaps.

Further rain set back Thursday’s start still further, with most courts out of action until 3 pm, four hours after they were due to begin.

“Due to the rain and dust overnight the outside courts need high pressure cleaning,” organisers tweeted. “Our team is working across Melbourne Park to prepare the outside courts for play,” they added.

Smog from the deadly wildfires hit hazardous levels during qualifying, leaving players with coughing fits and breathing problems and triggering a rash of complaints.

Although the haze cleared before the tournament’s start on Monday, it was replaced by torrential rain, which wiped out half of the day’s schedule and caused a backlog of matches.

Strong winds then buffeted Melbourne Park on Wednesday, giving players further problems as balls blew off-course and wobbled in the air.