South-east Australia is set to swelter this weekend, with temperatures forecast to reach highs of 29C in Melbourne and 36C in Sydney.
The unusual heat is likely to impact both the NRL and AFL grand finals, with the NRL reportedly planning ahead with extended breaks and play potentially delayed depending on the conditions.
Most of New South Wales, South Australia and Victoria have forecast temperatures 8C above the September average.
Long term climate data shows the maximum daily temperatures for much of the weekend in Melbourne and Canberra will be in the top 10% of max temperatures for this time of year.
As recent heatwaves in the United Kingdom have shown, it’s not just absolute temperatures that are important, but how they relate to how people have become acclimatised.
“You can have relatively mild conditions in the UK, by Australian standards, that have just as big an impact as if conditions were much more severe in Australia,” says Dr Aaron Bach, a research fellow at Griffith University.
“So it might only get to 35C for a few days in England and their building infrastructure – the built environment in general, not just inside the home but all over the place – is not really equipped for that heat.
“Each city and region and climate zone will have its own limits. And people have built and become accustomed to those limits. The human body adapts to those limits. So when we have these short, sharp bursts above those limits, we’re not quite ready for that.”
Experts warn of increased risk, especially for vulnerable Australians, from the sudden unseasonably hot weather.
“Heat doesn’t just impact from heat exhaustion or heat stroke, it makes the whole body have to work harder,” says Bach.
“And if you have [certain] underlying conditions, it’s those conditions that are sort of the weak link in the chain.
“You’ll see an increase in cardiovascular conditions or an increase in complications from diabetes or kidney function diseases, renal diseases. And it’s these kind of flow on effects that are more worrying than the direct effects of heat, stroke and heat exhaustion.”
Bach says the NRL and AFL, which are typically winter sports, will likely have to put their heat policies into effect more often in the future.
“Those spring and autumn seasons will become more and more like summer over the years in the decades ahead, so we’re going to start seeing this not [only] on grand final day, but in the last few rounds of the season.”