Heatwaves becoming hotter and longer, accelerating faster than global warming

Climate change will not only make heat waves hotter and longer, but will also cause their duration to increase at an accelerating pace with every additional fraction of a degree of global warming, according to new research.

The study, published in the journal Nature Geoscience, found that the longest and rarest heat waves, some lasting for weeks, are likely to see the biggest increases in both duration and frequency as the planet continues to warm.

Researchers from the University of California, Los Angeles (UCLA) and the Universidad Adolfo Ibanez in Santiago, Chile, found that each additional increment of warming will have a greater impact on extending heat waves than the previous one.

“Each fraction of a degree of warming will have more impact than the last,” said David Neelin, a UCLA climate scientist and senior author of the study. The findings underline the urgent need to accelerate adaptation planning. (Photo: PTI)

The findings raise fresh concerns about the growing risks posed by prolonged extreme heat to human health, animals, agriculture and ecosystems.

Longer heat waves can also intensify drought conditions, increase stress on power grids and worsen the risk of wildfires.

The researchers developed an equation that allows scientists to study the changing behaviour of heat waves in individual regions or examine patterns across multiple regions. Their approach also incorporates how temperatures on one day influence temperatures on the days that follow, a factor that helped reveal the accelerating trend at a global scale.

The study found that the longest and rarest heat waves in a region are expected to show the greatest increase in frequency.

“We found that the longest and rarest heat waves in each region, those lasting for weeks, are the ones that show the greatest increases in frequency,” said lead author Cristian Martinez-Villalobos. Southeast Asia and equatorial regions of Africa and South America could face some of the most dramatic changes. (Photo: PTI)

The impacts are unlikely to be distributed equally across the planet. Tropical regions, where temperature variations are generally smaller, are expected to experience larger changes than temperate regions. Summer heat waves are also projected to lengthen more rapidly than winter warm spells.

Southeast Asia and equatorial regions of Africa and South America could face some of the most dramatic changes.

The researchers projected that heat waves lasting more than 35 days in equatorial Africa could become 60 times more frequent in the near future, between 2020 and 2044, compared with the period from 1990 to 2014.

The researchers said the findings underline the urgent need to accelerate adaptation planning. As warming continues, cities, farms and power systems may need to prepare for heat events that last not just days, but increasingly for weeks.

The challenge, scientists warn, is that adaptation will need to speed up even if the pace of global warming remains unchanged.- EndsPublished By: Sibu Kumar TripathiPublished On: Sep 14, 2026 12:41 IST