Mud stops play: after smog, wind, rain, new challenge for Aussie Open

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 dirty surfaces, delaying matches by more than two hours on most of the courts.

"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.

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.

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.

The year's opening Grand Slam is more accustomed to a different kind of problem: extreme heat, which frequently causes players to don ice towels and occasionally halts matches.

Melbourne, on Australia's southern coast, has a well-earned reputation for changeable weather, as it is prone to both cold Antarctic winds blowing across the Southern Ocean, and hot Outback breezes -- sometimes in the same day.

Extreme weather is a growing concern in Australia after the bushfire emergency of recent months, which has left 29 dead and ravaged vast swathes of the country, torching thousands of homes.