Climate change exposes hundreds of millions to longer and deadlier pre-monsoon heat in South Asia

The study finds that anthropogenic climate change approximately tripled the probability of the April 2026 heatwave in northwestern India and Pakistan, making it about 1°C hotter than it would have been in a preindustrial climate. Analysis indicates that extreme heat is occurring earlier in the season, with the likelihood and intensity of April events increasing more rapidly than those in May. This trend extends the period of dangerous heat exposure for hundreds of millions of people, compounding risks to health, agriculture, and the economy. The report also highlights systemic vulnerabilities, noting that heatwaves are not officially declared disasters in India and Pakistan, which limits access to relief funding.

• Human-induced climate change significantly increased both the likelihood and intensity of the 15-day heatwave in April 2026, approximately tripling the probability of such an event and making it about 1°C hotter than in a preindustrial climate.
• Extreme heat is increasing more rapidly in April than in May, resulting in a longer overall period of extreme heat for South Asia and increasing the risk of intense dry heat before the monsoon begins.
• In the ten years since 2016, the intensity of such heat events has increased by 0.3°C and the likelihood has risen by approximately 35%.
• Future projections indicate that with an additional 1.3°C of warming, these pre-monsoon heat events will become more than twice as likely and 1.2°C hotter.
• The warming trend in this region is partially offset by atmospheric aerosols and increased land surface irrigation, but these same factors increase relative humidity, which amplifies heat stress.
• Vulnerable populations, including outdoor workers and those in poor-quality housing, are disproportionately exposed to heat-related mortality, yet heatwaves are often ineligible for disaster relief funding in India and Pakistan because they are not notified or declared disasters.

APA

Zachariah, M., Clarke, B., Bergin, C., T, A., Saeed, F., Pundeer, V., Vahlberg, M., & Kimutai, J. (2026). Climate change exposes hundreds of millions to longer and deadlier pre-monsoon heat in South Asia. World Weather Attribution. https://www.worldweatherattribution.org/climate-change-exposes-hundreds-of-millions-to-longer-and-deadlier-pre-monsoon-heat-in-south-asia/

Chicago

Zachariah, Mariam, Ben Clarke, Claire Bergin, Arulalan T, Fahad Saeed, Vedanshee Pundeer, Maja Vahlberg, and Joyce Kimutai. Climate change exposes hundreds of millions to longer and deadlier pre-monsoon heat in South Asia. World Weather Attribution, 2026. https://www.worldweatherattribution.org/climate-change-exposes-hundreds-of-millions-to-longer-and-deadlier-pre-monsoon-heat-in-south-asia/.

Wikipedia

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BibTeX

@techreport{zachariah2026climate, author = {Zachariah, Mariam and Clarke, Ben and Bergin, Claire and T, Arulalan and Saeed, Fahad and Pundeer, Vedanshee and Vahlberg, Maja and Kimutai, Joyce}, title = {{Climate change exposes hundreds of millions to longer and deadlier pre-monsoon heat in South Asia}}, institution = {World Weather Attribution}, year = {2026}, month = may, url = {https://www.worldweatherattribution.org/climate-change-exposes-hundreds-of-millions-to-longer-and-deadlier-pre-monsoon-heat-in-south-asia/}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }