Heatwaves are more than a nuisance - they are a health hazard in our warming world

 

Well this last week of November 2025 certainly brought a reminder that heatwaves are not just a feature of an Australian summer, they are also a definite health hazard for many in our communities. 

Particularly those with pre-existing health conditions, as well as the very young and those in older age brackets. People who work outdoors are also at increased risk. 

[Australian Climate Service, 2025, "Australia’s National Climate Risk Assessment"]

Between 1990 and 2023, the average annual number of heat wave days was 15.6 days. 

[Monash University, News, 21 July 2025, "30+ years of heat wave data to reduce impacts of extreme heat"]

In the four years between 2016 and 2019, the deaths of 1,006 people were attributable to heatwave conditions. 

[Zhihu Xu, et al, Sept 2025,Mapping heatwave-related mortality across 2288 local communities in Australia: a nationwide time-series analysis"]

During those same four years the annual heatwave-related attributable mortality rate (per 100,000 residents per year) was 1.08 nationally. While New South Wales had an annual heatwave-related attributable mortality rate (per 100,000 residents per year) of 1.38.

By way of examples closer to home, when it came to the annual heatwave-related attributable mortality rate in North East NSW during 2016-2019:

Casino Region mortality rate was 5;

Kyogle mortality rate was 4.6;

Maclean-Yamba-Iluka area mortality rate 3.7; 

Murwillumbah mortality rate 2.9;

Lismore Region mortality rate 2.6;

Grafton Region mortality rate was 1.9; and

Lennox Head-Skennars Head mortality rate 0.9. 

[The Guardian, 17 Sept 2025, "Heatwaves caused more than 1,000 deaths in Australia over four-year period, study finds"]

From 2019 to 2022, there were 2,143 hospital admissions related to extreme heat, including 717 patients from Queensland, 410 from Victoria, 348 from NSW, 266 from South Australia, 267 from Western Australia, 73 from the Northern Territory, 23 from the ACT and 19 from Tasmania. 

[AIHW, media release, 2 Nov 2023, "Extreme weather is leading to more injury hospitalisations, with heat being the main cause"]