Actuaries Climate Index Down Slightly in Latest Five-Year Average

Fall 2020 data update lowers index benchmark for the first time since 2017

Washington, D.C., Arlington, VA, Schaumburg, IL, and Ottawa, ON (June 8, 2021) –– The five-year moving average of the Actuaries Climate Index ( fell for the first time since 2017, according to the latest data release that includes fall 2020. The five-year moving average now sits at 1.22 relative to an average of zero during the 1961–1990 reference period.

“The five-year average declined because the latest seasonal measure of changes in weather extremes and sea level replaced an even higher seasonal value from the fall of 2015 that cycled out of the calculation of the average,” says Doug Collins, chair of the Climate Index Working Group.

While lower than the fall 2015 value, which was 1.70, the newly released fall 2020 seasonal value (1.33) remains at a high level relative to the ACI’s reference period. “The fall 2020 value was higher than any season before 2010,” Collins notes.


The Actuaries Climate Index is based on analysis of seasonal data from neutral, scientific sources for six index components collected since 1961. The index measures changes in these components for the United States and Canada combined and by region. Combining six components over a five-year measurement period, the index’s moving average smooths out monthly and seasonal fluctuations for a meaningful measurement of long-term climate trends.

The index, sponsored by the American Academy of Actuaries, the Canadian Institute of Actuaries, the Casualty Actuarial Society, and the Society of Actuaries, is designed to provide actuaries, public policymakers, and the general public with objective data about changes in the frequency of extreme climate conditions over recent decades.

Updated values are posted quarterly on as data for each meteorological season become available.

About the Sponsoring Organizations

The American Academy of Actuaries is a 19,500-member professional association whose mission is to serve the public and the U.S. actuarial profession. For more than 50 years, the Academy has assisted public policymakers on all levels by providing leadership, objective expertise, and actuarial advice on risk and financial security issues. The Academy also sets qualification, practice, and professionalism standards for actuaries in the United States.

The Canadian Institute of Actuaries (CIA) is the national, bilingual organization and voice of the actuarial profession in Canada. Our more than 6,000 members are dedicated to providing actuarial services and advice of the highest quality. The Institute holds the duty of the profession to the public above the needs of the profession and its members.

The Casualty Actuarial Society (CAS) is a leading international organization for credentialing and professional education. Founded in 1914, the CAS is the world’s only actuarial organization focused exclusively on property and casualty risks and serves over 9,000 members worldwide. Professionals educated by the CAS empower business and government to make well-informed strategic, financial and operational decisions.

With roots dating back to 1889, the Society of Actuaries (SOA) is the world’s largest actuarial professional organization with more than 32,000 actuaries as members. Through research and education, the SOA’s mission is to advance actuarial knowledge and to enhance the ability of actuaries to provide expert advice and relevant solutions for financial, business and societal challenges. The SOA’s vision is for actuaries to be the leading professionals in the measurement and management of risk.