The United States’ National Oceanic and Atmospheric Administration (NOAA) confirmed this month that an El Niño has formed in the equatorial Pacific, and placed the odds at about 63% that it will strengthen into a “very strong” — colloquially, a “super” — event by the northern winter. India’s June rainfall, until 16th June, is roughly 35% below normal. The combination has revived a question that returns with every El Niño year: how reliably do the strongest of these events translate into a failed Indian monsoon?
An El Niño is the periodic warming of the central and eastern equatorial Pacific that tends to weaken the South Asian monsoon and whose potency is measured by how far sea-surface temperatures in a reference patch of the Pacific climb above their long-term average. D.S. Pai, Chief Forecaster at the India Meteorological Department’s (IMD) Regional Meteorological Centre in Chennai, sets out the gradations: a departure of 0.5 to 1 degree Celsius is classed as ‘weak,’ 1 to 1.5 as ‘moderate,’ 1.5 to 2 as ‘strong’, and anything beyond 2 degrees as ‘very strong.’ “People call that very strong … as you wish, super,” he told The Hindu, adding that some forecasts suggest the current event could approach a record of around 2.5 degrees.
Following a calendar
What pushes an event into that range is a self-reinforcing process. The trade winds that normally drive warm surface water westward towards Asia weaken; the eastern Pacific warms, which in turn slackens the winds further generating a feedback loop that amplifies the anomaly. Scientists note that a warmer baseline ocean, the result of long-term climate change, has raised the heat available to recent events, making them more intense than earlier ones.
In the long term however, such events remain rare. Only a handful, the instrumental record shows, have crossed the 2° threshold — 1972-73, 1982-83, 1997-98 and 2015-16.
El Niño also follows a consistent calendar, which bears directly on its monsoon impact. “It starts in one spring season, peaks in the winter, and very fast it weakens in the next spring,” Dr. Pai said, noting that an event very occasionally persists into a second year. Because the warming establishes only in spring and matures later, he said, its suppressing effect on the monsoon is felt mainly in the middle and later part of the June-September season rather than at its start. June rainfall and the pace of onset, he added, are governed largely by local and regional factors — so a weak June, including the present 35% shortfall, is not by itself a reliable guide to the season.
The 1982-83 El Niño was associated with severe drought and bushfires in Australia and dry conditions across Indonesia. The 1997-98 event drove severe forest fires and choking haze across Indonesia and Southeast Asia, killed an estimated one-sixth of the world’s coral, and helped push global temperatures to a record. The 2015-16 episode triggered mass bleaching of the Great Barrier Reef, made 2016 the warmest year then recorded, and catalysed severe drought and food shortages across southern and eastern Africa.
Paradoxically, the 1997-98 El Niño actually brought more rains — 2% more — than what’s usual for India’s summer monsoon months. This was due to a counteracting effect in the Indian Ocean, called the Indian Ocean Dipole, that brought in warm water pools, countering the Pacific-induced drying. Since that year, forecasters have consistently watched for the Dipole’s waxing and waning — particularly during El Niño monsoons — to estimate how much of it can be buffered. One of the reasons, IMD Director General, M. Mohapatra has said, for a monsoon deficit this year is that the Dipole wouldn’t be strong enough to counter the Nino.
Rainfall distribution
Setting the El Niño years since 1950 against IMD’s long-period rainfall series shows that, of roughly two dozen such years — the exact count depends on how the weaker events are classified — about 15 produced a below-normal monsoon and around 10 tipped into outright deficiency, defined as seasonal rainfall below 90% of the long-period average. That is close to three in five, a correlation strong enough to shape food and fiscal planning. Several of India’s worst droughts fell in El Niño years, among them 1972, 1982, 2009, and 2015.
“The problem is not just the total reduction in rainfall, but the way the rainfall is distributed,” G.V. Ramanjaneyulu, Executive Director, Centre for Sustainable Agriculture said in a statement, “The delay in the onset of rainfall, along with dry spells that may occur in between, will be the more serious issues. Predictions suggest that this could be one of the worst monsoons in the past 150 years.”
El Niño also redistributes the world’s tropical cyclones rather than simply adding to them. NOAA’s research arm notes that the warming generally suppresses Atlantic hurricane activity by strengthening vertical wind shear — the change in wind speed and direction with height that can tear a developing storm apart — while making conditions more favourable for hurricanes in the central and eastern Pacific. The effect tends to scale with the event’s strength, and for the basins closer to Asia the signal runs the other way: forecasters note that during an El Niño the odds of a Pacific storm intensifying into a super typhoon rise appreciably, though such systems typically recurve towards East Asia and the Americas rather than the Indian subcontinent.
The wider context is a steadily warming ocean. Each super El Niño has developed in a warmer Pacific than the one before, and forecasters expect the current event to push global temperatures higher still; Dr. Pai anticipates that 2027 could rank as the warmest year on record and may carry the world — akin to 2024 — temporarily past the 1.5-degree Celsius threshold set under the Paris Agreement.
jacob.koshy@thehindu.co.in
Published – June 18, 2026 07:45 am IST
