First, What Exactly Is El Niño?
Think of El Niño as a massive, temporary warming of the ocean. Every two to seven years, the surface waters of the central and eastern Pacific Ocean become significantly warmer than average. This isn't just a local heatwave; it's a vast shift in the planet's
climate system, powerful enough to disrupt weather patterns across the globe. The phenomenon is the warm phase of a larger cycle called the El Niño-Southern Oscillation, or ENSO. It happens when the normal east-to-west trade winds along the equator weaken, allowing warm water that is usually piled up in the western Pacific to slosh back eastward. This change in ocean temperature sets off a chain reaction in the atmosphere above, altering rainfall and temperature from South America to Southeast Asia.
The Pacific's Ripple Effect on India
Thousands of kilometres away, this warming in the Pacific has a direct, and often negative, impact on India's southwest monsoon. The monsoon is essentially a giant sea breeze, driven by temperature differences between the Indian subcontinent and the ocean. El Niño disrupts this delicate balance. The altered atmospheric circulation patterns can suppress the formation of clouds and weaken the monsoon winds that bring rain to the mainland. Historically, many of India’s most severe droughts have coincided with strong El Niño years. The connection is so well-established that the emergence of El Niño conditions automatically puts weather watchers and policymakers on high alert, as it raises the probability of below-normal rainfall, which can have cascading effects on the country.
What Forecasters Are Seeing in 2026
The 2026 season is unfolding as a classic example of this connection. The India Meteorological Department (IMD) forecast a 'below-normal' monsoon for the year, predicting rainfall to be around 90% of the long-period average. This forecast was made in anticipation of a developing El Niño. So far, the prediction has been largely accurate. As of mid-August 2026, cumulative rainfall across the country was running at a deficit of around 12%. This was primarily driven by a significantly dry June, which saw a rainfall deficit of over 35%, even though July rainfall was closer to normal. Now, forecasters at agencies like the US-based NOAA are warning that the current El Niño could strengthen to become a 'strong' or even 'historic' event by the end of the year.
More Than Just a One-Man Show
However, the relationship between El Niño and the Indian monsoon is not a simple one-to-one equation. Not every El Niño year results in a drought. Other climate factors can either worsen or cushion the blow. The most significant of these is the Indian Ocean Dipole (IOD), sometimes called the Indian Ocean's own version of El Niño. The IOD refers to the temperature difference between the western and eastern parts of the Indian Ocean. A 'positive' IOD, with warmer waters in the west, can help boost monsoon rains and sometimes counteract El Niño's negative effects. For 2026, the IOD has been neutral, but forecasters note that it could turn positive towards the end of the season, potentially offering some late relief.
A Question of Critical Timing
Another crucial factor this year is timing. El Niño's influence on Indian weather doesn't happen instantaneously; there is typically a time lag of several weeks as the atmospheric changes make their way across the globe. The current powerful El Niño is expected to peak in the winter of the Northern Hemisphere. This means its strongest effects on India might be felt later in the year, after the southwest monsoon's official withdrawal date of September 30. While it has certainly influenced the current monsoon's below-average performance, its full force might have a greater bearing on post-monsoon rainfall and winter weather patterns across the country.
