Super El Nino

Super El Niño 2026 has strong implications for India’s Monsoon and Tamil Nadu Flood Risk. Read here to learn more.

The World Meteorological Organisation (WMO), in its Global Seasonal Climate Update issued on 8 October 2026, warned that the ongoing El Niño is intensifying and could become one of the strongest on record.

The Niño 3.4 sea-surface-temperature anomaly is forecast to reach approximately +3.7°C during October-December 2026, potentially exceeding the previous peak of +2.6°C recorded during November 2015-January 2016.

The development raises concerns about global temperature records, rainfall variability, drought and flood risks. For India, the impact will depend on the interaction of El Niño with the Indian Ocean Dipole (IOD), the Madden-Julian Oscillation (MJO) and regional weather systems.

What is El Niño?

El Niño is the warm phase of the El Niño-Southern Oscillation (ENSO), a coupled ocean-atmosphere phenomenon originating in the tropical Pacific Ocean.

• Under normal conditions, easterly trade winds push warm surface waters toward the western Pacific, allowing colder, nutrient-rich water to rise along South America’s western coast.
• During El Niño, these trade winds weaken, warm water spreads towards the central and eastern Pacific, and the upwelling of cold water off Peru and Ecuador is suppressed.
• This warming alters atmospheric circulation, shifting rainfall patterns and influencing temperatures across the world.
• The Oceanic Niño Index (ONI) traditionally identifies El Niño when the three-month running mean of Niño 3.4 sea-surface-temperature anomalies reaches at least +0.5°C and persists for the required number of overlapping seasons, alongside the broader ocean-atmosphere context.

What is a Super El Niño?

“Super El Niño” is an informal expression used to describe an exceptionally strong El Niño event.

• It is commonly associated with Niño 3.4 anomalies of around +2°C or more, although the term has no universally established official classification.
• The current forecast of approximately +3.7°C would indicate an exceptionally strong event if realised.
• However, the forecast should not be interpreted as certainty about its eventual peak or its precise regional impacts.

How Does El Niño Influence India’s Monsoon?

1. Walker circulation

• The Walker circulation is an east-west atmospheric circulation system over the tropical Pacific. During El Niño, its rising branch and major areas of convection shift eastward, altering atmospheric pressure and circulation over the Indian Ocean.
• These changes can weaken monsoon circulation over India, reduce moisture transport and suppress rainfall during the June-September Southwest Monsoon.
• Consequently, El Niño is an important risk factor for deficient monsoon rainfall, although it does not determine the outcome by itself.

2. Indian Ocean Dipole

The Indian Ocean Dipole (IOD) is a climate phenomenon involving differences in sea-surface temperatures between the western and eastern equatorial Indian Ocean.

• Positive IOD: The western Indian Ocean is relatively warmer than the eastern Indian Ocean. It can strengthen moisture transport and partly counteract El Niño’s adverse influence on the Indian summer monsoon.
• Negative IOD: The eastern Indian Ocean is relatively warmer, potentially reinforcing conditions unfavourable to Indian monsoon rainfall.

The WMO’s October-December 2026 outlook forecasts a positive IOD, with a seasonal mean anomaly of approximately +0.5°C. Its evolution and interaction with El Niño will influence regional rainfall patterns.

3. El Niño Modoki

• El Niño Modoki is a form of Pacific warming concentrated in the central Pacific, with relatively cooler conditions towards the eastern and western ends.
• Its atmospheric effects can differ from those of a conventional eastern-Pacific El Niño.
• However, its effects on Indian rainfall and cyclone activity are not uniform. The location and intensity of warming, background ocean conditions and atmospheric circulation all influence the outcome.

4. Madden-Julian Oscillation

• The MJO is a large-scale pattern of enhanced and suppressed tropical rainfall that moves eastward around the equator, typically over a period of several weeks.
• Its active phase can promote convection and rainfall over the Indian Ocean, while its suppressed phase can temporarily inhibit them.
• MJO activity may therefore alter the timing and intensity of rainfall even during a strong El Niño.

Why Can Tamil Nadu Experience Heavy Rainfall During El Niño?

India’s Southwest Monsoon occurs mainly from June to September, whereas the Northeast Monsoon occurs primarily from October to December and is particularly important for Tamil Nadu and parts of southeastern India.

• Tamil Nadu receives a substantial share of its annual rainfall during the Northeast Monsoon.
• The retreat of the Southwest Monsoon, the establishment of northeasterly winds and the formation of low-pressure systems over the Bay of Bengal influence rainfall along the coast.
• Research has found that El Niño years have often been associated with enhanced Northeast Monsoon rainfall over southern peninsular India, including Tamil Nadu.
• Nevertheless, this is a statistical relationship rather than a guarantee of excess rainfall in every El Niño year.

Several factors shape the outcome:

• Bay of Bengal weather systems: Low-pressure areas, depressions and cyclones can bring intense rainfall to coastal Tamil Nadu. Their tracks, intensity and interaction with coastal geography are critical.
• Ocean heat and moisture: Warmer sea surfaces can provide additional heat and moisture to developing weather systems, although atmospheric conditions determine whether this translates into heavy rainfall.
• Seasonal wind reversal: The northeast monsoon brings winds from the northeast towards southeastern India. Their interaction with Bay of Bengal disturbances can produce concentrated rainfall.
• East India Coastal Current (EICC): This current reverses seasonally along India’s eastern coast, broadly changing from poleward flow in the warmer months to equatorward flow during the post-monsoon and winter period. It forms part of the regional ocean circulation system, but a direct causal link between its 2026 behaviour and extreme Tamil Nadu rainfall should not be assumed without specific evidence.

Thus, a strong El Niño may coincide with a weaker Southwest Monsoon over much of India and a wet Northeast Monsoon over Tamil Nadu. The two outcomes are not contradictory because they occur in different seasons under different regional circulation patterns.

Historical Context

• 1876-1878: Severe drought and famine affected large parts of India during this period. Historical reconstructions associate the period with major climate variability, including El Niño-related conditions, but famine mortality also reflected colonial policies, poverty and failures of relief.
• 1997-1998: A powerful El Niño occurred alongside a strong positive IOD. India received broadly normal Southwest Monsoon rainfall, illustrating how other oceanic drivers can modify El Niño’s effects.
• 2015-2016: The strong El Niño was associated with deficient Southwest Monsoon rainfall in India. Tamil Nadu, however, experienced devastating floods in December 2015 during its Northeast Monsoon, demonstrating the importance of regional and seasonal differences.

These examples show why the strength of El Niño alone cannot reliably predict rainfall over a particular Indian state.

Potential Impacts on India

1. Agriculture and rural livelihoods

• A deficient Southwest Monsoon can reduce soil moisture, reservoir inflows and crop yields, particularly in rain-fed agricultural regions.
• This may increase irrigation demand, raise cultivation costs and affect rural incomes.

2. Water and energy security

• Reduced rainfall can put pressure on drinking-water supplies, groundwater and hydropower generation.
• At the same time, higher temperatures may increase electricity demand for cooling and irrigation pumping.

3. Food prices and inflation

• Weather-related crop losses can raise prices of vegetables, pulses and other agricultural commodities.
• The scale of the impact will depend on crop conditions, irrigation availability, food stocks, trade policy and market responses.

4. Urban flooding in Tamil Nadu

• Intense Northeast Monsoon rainfall can overwhelm drainage systems, flood low-lying neighbourhoods and disrupt transport, electricity and essential services.
• The risk is heightened where wetlands, lakes and natural drainage channels have been encroached upon or obstructed.

5. Public health

• Floods can contaminate drinking-water sources and increase the risk of waterborne diseases.
• Drought and heat can also affect sanitation, livelihoods and access to safe water, making climate preparedness a public-health priority.

Challenges in Forecasting and Managing the Event

• Seasonal uncertainty: Forecasts of ocean temperatures are more reliable at some lead times than precise local rainfall forecasts. A strong El Niño does not translate directly into a fixed rainfall deficit or flood outcome.
• Compound climate drivers: El Niño, IOD, MJO, Indian Ocean conditions and regional disturbances interact, making impacts difficult to attribute to a single factor.
• Uneven vulnerability: Rain-fed farmers, informal urban settlements and communities dependent on local water sources may face greater exposure and have fewer resources to recover.
• Infrastructure limitations: Inadequate stormwater drainage, wetland loss, poor reservoir coordination and limited flood-warning coverage can turn extreme rainfall into a disaster.

Way Forward

• Strengthen impact-based forecasts: The India Meteorological Department and state agencies should translate seasonal outlooks into district-level advisories for agriculture, water management, public health and disaster response.
• Prepare for both drought and floods: Water planning should account for potential Southwest Monsoon deficits while Tamil Nadu improves readiness for intense Northeast Monsoon rainfall.
• Build climate-resilient agriculture: Promote crop diversification, drought-tolerant varieties, efficient irrigation, soil-moisture conservation and timely weather-based advisories.
• Improve urban flood management: Restore wetlands and natural drainage channels, enforce floodplain zoning, upgrade stormwater infrastructure and strengthen last-mile early-warning systems.
• Manage reservoirs and groundwater sustainably: Use rainfall and inflow forecasts to improve reservoir operations, recharge groundwater where feasible and protect drinking-water supplies.
• Strengthen regional climate monitoring: Improve observations of Pacific and Indian Ocean temperatures, coastal currents, atmospheric circulation and local rainfall to refine seasonal and short-range forecasts.
• Integrate climate risk into planning: Incorporate ENSO-related risks into crop insurance, disaster-management plans, public-health preparedness and state climate adaptation strategies.

Conclusion

The potential Super El Niño of 2026-27 highlights the growing importance of climate-informed planning. Its effects on India will not be uniform: a weakened Southwest Monsoon could increase drought and agricultural risks, while Tamil Nadu may face heavy rainfall during the Northeast Monsoon.

Preparedness must therefore be regional, seasonal and impact-based, combining reliable forecasts with resilient agriculture, sound water management and climate-sensitive urban planning.