Australian Open moves play with 40C heat expected

Play will start 30 minutes earlier at the Australian Open on Saturday with temperatures set to reach 40C in Melbourne.

Play will begin on all courts at 10:30 local time (23:30 GMT) instead of the usual 11:00 start.

The Australian Bureau of Meteorology has issued a severe heatwave warning in Melbourne and the state of Victoria.

Play will be suspended at the Australian Open if the tournament's heat stress scale hits its maximum of five.

"It's not a lot of fun playing in those temperatures," said American men's 19th seed Tommy Paul.

The scale measures four factors: radiant heat (or the strength of the sun), air temperature in the shade, relative humidity and wind speed.

If a five is recorded on the heat stress scale, matches on Rod Laver Arena, Margaret Court Arena and John Cain Arena will stop to allow the roof to be closed before play can continue.

Defending women's champion Madison Keys and Czech former world number one Karolina Pliskova open play on Laver, followed by defending champion Jannik Sinner.

Another American seed, Jessica Pegula, and Italian men's fifth seed Lorenzo Musetti are among the early starters on Court and Cain.

"I wouldn't like to play the match because I think it's too much on our bodies. I'm glad that at least we have a heat rule," world number one Aryna Sabalenka said.

Ballkids will work 45-minute rotations instead of the usual one hour, with an increased one-and-a-half hour break between shifts.

Another 100,000-strong crowd is expected at Melbourne Park for Saturday's third-round matches.

The Australian Open says there will be facilities throughout the site helping people cool down, including:

Temperatures are also predicted to top 40C on Tuesday, when the singles quarter-finals are scheduled to begin.

"The weather being crazy [means] a lot of adjustment on the strings and your approach to the match," said Sabalenka, who plays Canadian teenager Victoria Mboko in the fourth round on Sunday.

"It's going like a rollercoaster. We'll see who adjusts better in the next days."

Rain will not stop play in Melbourne this weekend or early next week - but the heat might.

It will not be exceptional heat all the way, however, as the city is set to experience some wild swings in temperatures.

That is all down to Melbourne's location on the south-east coast of Australia.

With the desert interior to the north, and the chilly Southern Ocean and Antarctica to the south, a quick change in wind direction can have you reaching for a fan one day and grabbing your jumper the next.

During the summer the interior of Australia heats up rapidly, and any wind that blows in from a northerly direction will bring that searing heat with it.

However, any switch to a southerly wind will blow in air off a sea that sits at around 16-18C this time of year - the city's own version of natural air conditioning.

If the origin of this wind comes a long way from the south, then you are tapping into even colder conditions and, of course, grabbing those warmer clothes.