Tech · CA · 05:00

Heat waves on land are starting earlier and lasting longer globally

Phys.org · Tech

Published 23 Sep 2026, 05:00 EDT · Updated 23 Sep 2026, 06:59 EDT

• Heat waves over land worldwide are beginning earlier and ending later, while occurring over longer seasons.
• The first heat wave of the season has recently shifted toward faster onset, according to research published in Nature Climate Change.
• Researchers analyzed global climate data from 1979 to 2023 and found the first heat wave began 3.29 days earlier per decade.
• The last heat wave ended 5.41 days later per decade, extending the heat wave season by 8.71 days per decade.
• Over 45 years, the first heat wave advanced about two weeks and the heat wave season lengthened by about 39 days.