Extreme weather conditions including unusually heavy rainfall across the east coast drove the quarterly Australian Actuaries Climate Index to its highest level ever.

High temperatures in northern Australia also contributed to the record autumn reading, the Actuaries Institute says.

“The Australian Actuaries Climate Index clearly shows extreme weather conditions are a ‘here and now’ challenge,” President Annette King said.

“It underscores the importance of all stakeholders embracing solutions - from investment in adaptation and resilience to improved disclosures and reducing greenhouse gas emissions.”

The institute launched the index in November 2018 to measure extreme weather conditions and changes to sea levels using data from the Bureau of Meteorology.

Quarterly updates are provided, based on six components measuring changes in the frequency of extreme high and low temperatures, heavy rainfall, dry days, strong winds and changes in sea levels across 12 Australian regions that are climatically similar.

The index’s latest reading released today shows the influence of the rain-boosting La Nina event over the east coast earlier this year.

The East Coast South region, which covers Sydney and most of the NSW coast, set a record for extreme rainfall, the Actuaries Institute says.

And the Wet Tropics region, which includes the northern most parts of Queensland, recorded the second highest index value for extreme rainfall since the index began.

“This was influenced by the ongoing La Nina weather system that stayed in place throughout the season,” the Actuaries Institute says. “On the ground there was a continuation of the severe flooding that started in the previous season.

“The combination of saturated soil conditions and continued heavy rainfall throughout the season meant flooding persisted throughout the period for much of Queensland and NSW. This continues in winter.”

At the same time, extreme high temperatures were experienced in the northern parts of the country during autumn.

The Wet Tropics and Monsoonal North regions both saw the second highest extreme high temperature index value, while the East Coast North region recorded the third highest value since the index began.

Finity Consulting, the actuarial firm that calculates the index, says the extreme weather is consistent with the warnings of climate scientists.

“It is important that we invest in improving the resilience of our communities in light of trends in extreme weather, Finity Principal Rade Musulin said.

While the insurance industry is strong financially and can withstand these events, he says “we have seen before across the world severe losses can lead to market turbulence”.