Australasian Science: Australia's authority on science since 1938

The Tennis Is Hotting Up

Extreme summer temperatures in Melbourne have become more prevalent over summer, especially when the Australian Open tennis tournament runs, according to a study published in the Bulletin of the Australian Meteorological & Oceanographic Society.

Ben Hague of the University of Melbourne was motivated to conduct a historical observational study of temperature and humidity data in Melbourne after maximum temperatures exceeded 41°C for four consecutive days during the 2014 Australian Open. The heat wave caused heat-related stress for players, officials and spectators at the tournament.

“This was a particularly extreme event,” Hague says, “but the point of this study is to measure whether these events are happening more often. The results suggest that they are.”

Hague found that both hot days and measures of heat stress increased significantly across all of summer, but mainly in January – particularly mid–late January when the international tennis tournament takes place.

The study focused on temperature and humidity trends since 1987, which was when the Australian Open became a mid–late January event.

“The average afternoon temperatures during January have increased at a rate of 0.8°C per decade,” Hague says, “but the temperatures during the Australian Open’s afternoon sessions have risen by 1.25°C per decade. This is significant because this is the time when the players are on court: right in the heat of the afternoon.”

Despite humidity decreasing in Melbourne, the increases in temperature were large enough to significantly increase measures of heat stress experienced by Australian Open competitors, officials and spectators.

While the main focus of the study was the 27 years since the Australian Open moved to late January, Hague also investigated more than 100 years of Melbourne’s summers and saw an overall increase of both maximum and minimum temperatures during the season. He found that average daily maximum temperatures throughout all of summer have increased by 2°C since 1911. Astonishingly, 1.8°C of this warming occurred since 1990.

Melbourne’s hottest days are also getting hotter, with Hague saying that there has been a 5°C increase in the average temperature of Melbourne’s hottest December day since 1989.