El Niño events in India led to intensification of extreme daily rainfall, according to new research published in Science on September 18, 2025.
Although the well-documented effect of El Niño events is to decrease summer rainfall, it also paradoxically intensified extreme daily precipitation amounts. Throughout India, the study—using observational data spanning 1901 to 2020—found that El Niño events counterintuitively, simultaneously intensify extreme daily rainfall.
The research specifically examined extreme daily rain during El Niño years to reach the surprising conclusion. To understand the connection between rainfall in India and El Niño, the researchers analysed India Meteorological Department (IMD) daily rainfall records (1901-2020).
The study was led by Spencer A Hill from City College of New York, US. It found a direct connection between Indian rainfall and El Niño. In the drier regions of southeastern and northwestern India, the climate phenomenon reduces total rainfall and the intensity of extreme events. In the wet central and southwestern parts of the country, it results in less frequent but more intense downpours.
“This is partly driven by increases in extreme daily values of convective buoyancy, provided that both the undilute instability of near-surface air and the dilution by mixing with drier air above are considered,” said the study.
The key finding is that “you tend to get more days with extreme amounts of rainfall within India, not less, in El Niño summers. An El Niño event means that ocean surface temperatures in the eastern equatorial Pacific Ocean are warmer than usual,” said Spencer Hill.
The findings were unexpected because “it has been known for over a century that El Niños do precisely the opposite, meaning they promote drought, for total rainfall summed over the rainy season, June through September,” added Hill.
The research illuminated a complex facet of El Niño’s influence on India’s monsoon — while overall summer rainfall declines, the intensity and likelihood of damaging extreme downpours rise sharply in wetter areas.
The implications of the findings are manifold, especially in the context of a warming global climate. The researchers said El Niño could plausibly drive similar changes in other tropical regions and the framework used in the study could be further applied to changes in hourly extremes, to other internal variability modes, and to forced trends under climate change.
Extreme weather events can have devastating consequences, with flooding inundating villages, sweeping away homes and causing major economic hardship. Authorities and farmers need to better prepare for the dangerous events.
“This raises the prospect of skillful ENSO-based (El Niño–Southern Oscillation) seasonal forecasts of extreme rainfall probabilities within monsoonal India,” added the research team.
With more accurate forecasts that take into account El Niño patterns, India could better mitigate flood risks and protect lives and livelihoods.