El Nino may turn 'very strong' by late 2026: IRI; experts see elevated risk for India

New Delhi: The El Nino weather pattern is strengthening and is likely to become "very strong" in late 2026 and early 2027, the International Research Institute for Climate and Society (IRI) at Columbia University said, raising concerns over elevated climate risk for India.

In its latest ENSO forecast, published on September 21, the IRI said the Nino 3.4 index, a key gauge of Pacific Ocean temperatures, reached +3.0 degrees Celsius in mid-September.

All 22 models it surveyed, 13 dynamical and nine statistical, forecast "very strong" El Nino conditions through the 2026-27 winter.


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The IRI put the probability of El Nino at 100 per cent through February 2027, falling to 61 per cent by mid-2027. It said the event could rank among the strongest on record.

The institute also expects the Indian Ocean Dipole (IOD) to become strongly positive from September through December 2026 before returning toward neutral conditions in early 2027. A positive IOD often occurs alongside El Nino, though the two can develop independently, the IRI said.

For India, El Nino is typically associated with weaker monsoon rainfall and can affect crop output, although the IOD can sometimes offset those effects.

Experts said the combination of El Nino and a positive IOD matters for India because El Nino's impact is not determined by Nino 3.4 alone. The IOD, monsoon circulation, regional sea-surface temperatures and winter weather patterns also play a role.

"The IRI forecast is a strong indication of elevated climate risk, but it does not by itself provide a precise rainfall or agricultural-output forecast for India," they said.

El Nino is a natural climate pattern when a large part of the Pacific Ocean becomes unusually warm. For India, it can sometimes mean less monsoon rains, a warmer and drier winter and greater stress on crops and water availability.