The frequency of extreme high temperatures during Autumn 2019 was 96% above the long-term average, according to the Australian Actuaries Climate Index, forcing organisations such as the Australian Prudential and Regulatory Authority (APRA) to consider how they are going to handle climate change.
The quarterly data from the Actuaries Institute found Autumn was the second-most extreme in the number of hot days ever recorded in the three months from March. Only Autumn 2016 showed more extreme temperatures.
The index shows changes in frequency, rate of occurrence, extreme high and low temperature, heavy precipitation, dry days, strong winds and changes in sea levels.
Extreme changes in weather posed the greatest risk to people, communities, environment and the economy as well as increased the risk of bushfires.
Actuaries Institute chief executive, Elayne Grace, said: “There is a growing urgency to understand the occurrence of extremes and the impacts of climate change on businesses and communities.
"We have seen a strong rise in the momentum of interest from various parties, including from Australia's regulators, the Australian Prudential Regulation Authority and the Reserve Bank of Australia."
Actuaries Institute president Nicolette Rubinsztein said the quarterly data allowed regulators, companies, scientists and others to monitor trends in extremes, based on the data from weather bureau stations.
"It is crucial to build the Index over time, so we can assess change based on data and objectively contribute to this important public policy issue," she said.