Australian Actuaries Climate Index

The Australian Actuaries Climate Index (AACI) is designed to provide an easy to interpret and valuable metric for actuaries, policy decision-makers and the general public to refer to when monitoring changes in climate.



The AACI includes a series of component indices and a composite index.


► The component indices show changes in the frequency of extreme levels of each of temperature (high and low), rainfall, consecutive dry days, wind and sea level.


► The composite index, the AACI, combines the measures of high temperature, rainfall and sea level into a single index.

Many of the organisations that actuaries support are concerned with climate risk and with how it will affect their business - for example general insurers, banks and investment managers. The Index is intended to provide a useful measure of how the extremes of weather are changing in order to support assessment of the change in risk.


The Index and components examine how the frequency of extreme weather has changed compared against a reference period of 1981-2010 (except for the wind component for which the reference period has a later start date).



The Index, and components, are available for 12 regions of Australia.
Results are produced for each season such that, for example, autumn is compared to previous autumns.



The underlying data is derived from individual weather station and tide gauges from the Bureau of Meteorology.



Positive exceedances indicate the frequency of extreme weather and sea levels has increased compared with what was observed during the reference period. Negative exceedances indicate the frequency of extremes has reduced compared with what was observed during the reference period.
The Index was launched in 2018.



The Institute commissioned Finity Consulting to compile the Index ahead of its launch and they remain commissioned to provide the quarterly updates.

Download the  AACI Design Documentation .



The AACI was inspired by the  The Actuaries Climate Index™ (ACI) which has been developed in North America with a similar objective.



The Indexes cannot be directly compared due to different underlying components and exceedance thresholds.

Sample calculations and comments on the extremes of the Australian Actuaries Climate Index at particular geographic locations in Australia can be found  here .