This has just been an abnormally hot summer in southern Australia, coming after a normal one last year (with no heat complaints outside of a select few serial whingers) and a dramatically cooler than usual one two years ago - and the Australian Open is more often disrupted by rain than heat.
Melbourne's January stats have an average of only 3.6 days (out of 31) with maximum temperatures ≥ 35°C and only 0.7 days with a maximum temperature ≥ 40°C. There's actually over twice as much chance of it raining on any given January day in Melbourne (average of 8.3 days out of 31) than of it being really hot, and a look back at the history of the Australian Open would reflect that. There was one year the Yarra River flash-flooded from further upstream (no rain in central Melbourne) and the first the tennis people knew of it was during a prime night match when water came up from the stormwater drains and started turning Rod Laver Arena into a swimming pool* - which a then-teenager Martina Hingis used as such!
The UCI WorldTour teams were copping the same treatment on training rides around my home city of Adelaide last week leading up to the Tour Down Under, we had
five days in a row with maxima over 42°C. It was the first heatwave ever to meet the classification of 'severe' (above a heatwave but below an extreme heatwave) which illustrates how abnormal it has been. The TDU race stages have gone ahead in more normal summer weather this week, the bigger threat being a bushfire last weekend which was close to the area where a women's race was held on Monday and the first TDU stage on Tuesday but ended up not being a problem thanks to the heroic volunteer firefighters of the CFS.
The same statistics for Adelaide in January are:
Average days with maximum ≥ 35°C: 6.0 (currently eight for this month, and four more forecast to come)
Average days with maximum ≥ 40°C: 1.7 (currently five, two more to come)
Average number of rainy days: 4.4
I don't think the Australian Open needs to change location or dates but the extreme heat policy could do with some transparency and clarification to catch up with the better heat policies of other sports - and having the new retractable roof for Margaret Court Arena next year will help things as well. As long as it's not too extreme, the heat is a fair part of the game in Melbourne, just like the rain interruptions at Wimbledon, the wind at New York and the feral French crowds at Paris. Any other time would see more rain disruption, and it would take place outside of the summer holiday season which is so crucial for the sport of tennis in Australia when all the other big tournaments take place when people are asleep.
The first better heat policy example I can think of is cricket below elite national level. Adelaide had similar conditions last week while the national under-17 cricket cup was held here. They simply started play at 8am, allowed more liberal use of substitute fielders and shortened the games to 30 overs each.
The second better example is cycling. The stages of the Tour Down Under are restricted to a 150km competitive distance every year, and they'll start earlier in the day if the forecast is ≥40°C. The 'Challenge Tour' public event linked with stage 4 (I completed this yesterday, the full 155.4 km distance later covered by the same WorldTour teams which contest the Tour de France) would be cancelled if the forecast was for ≥40°C and participants encouraged to swap to a shorter distance and/or take a shortcut missing the King Of the Mountain climb. Unlike the opaque Australian Open heat policy, this was all in the Challenge Tour handbook posted online before Christmas.
* interestingly, a temporary competition pool was put in there for the Swimming World Championships a few years ago, and the stadium renamed the Susie O'Neill Pool for three weeks!
