What Happened
- Historical analysis of El Niño years since 1980 shows that approximately 70% of El Niño years coincided with deficient or below-normal Indian summer monsoon rainfall.
- Climate models now indicate that a strong El Niño is likely to develop within months, potentially affecting the 2026 southwest monsoon season.
- The IMD has already forecast 2026 monsoon rainfall at 92% of the Long Period Average (LPA) — placing it in the "below normal" category.
- The convergence of El Niño risks and already-forecast below-normal rainfall heightens the threat to India's kharif agriculture output, food prices, and rural economy.
- The statistical link between El Niño and deficient Indian monsoon, while strong, is not absolute — some El Niño years have seen normal or above-normal rainfall due to counteracting factors such as a positive Indian Ocean Dipole (IOD).
Static Topic Bridges
El Niño and the Walker Circulation: Mechanism
El Niño refers to the anomalous warming of the central and eastern tropical Pacific Ocean sea surface temperatures, typically occurring every 2–7 years. It disrupts the Walker Circulation — the large east-west atmospheric loop in the tropics — by weakening Pacific trade winds, shifting the warm water pool eastward, and suppressing convection over the western Pacific. This reduces moisture transport into South Asia, weakening the Indian monsoon.
- El Niño: warming of central-eastern Pacific SSTs by ≥0.5°C above normal for at least 5 consecutive 3-month periods
- La Niña: cooling of the same region; typically enhances Indian monsoon
- El Niño years since 1950: approximately 16 events
- Historically, 6 out of 10 El Niño years associated with below-normal or deficient Indian monsoon
- The statistical linkage is strongest over peninsular and northwest India; has weakened over central India in recent decades
Connection to this news: The probability of a strong El Niño developing in mid-2026 makes the IMD's "below normal" forecast for 2026 consistent with historical El Niño–monsoon patterns.
ENSO Monitoring and Forecasting
ENSO monitoring is conducted globally by national meteorological agencies and international bodies. In India, the IMD uses its Monsoon Mission Climate Forecast System (MMCFS) and Multi-Model Ensemble (MME) to predict monsoon variability under different ENSO states.
- Nino 3.4 region (5°N–5°S, 170°W–120°W): standard ENSO monitoring zone
- Southern Oscillation Index (SOI): pressure-based measure of ENSO; negative SOI = El Niño
- Spring predictability barrier (March–May): ENSO predictions beyond this period carry higher uncertainty
- NOAA (USA) and Bureau of Meteorology (Australia) also issue ENSO outlooks that inform IMD forecasts
Connection to this news: Climate models globally are signalling a transition from ENSO-neutral to El Niño conditions during mid-2026, strengthening the basis for IMD's below-normal monsoon forecast.
India's Monsoon and Agricultural Vulnerability
The southwest monsoon (June–September) delivers approximately 75% of India's annual rainfall and is the backbone of kharif agriculture. Rain-fed agriculture, which covers nearly 50% of India's cultivated area, is directly tied to monsoon performance. A below-normal or deficient monsoon reduces kharif crop yields (rice, pulses, oilseeds, cotton), pushes up food prices, reduces rural incomes, and can trigger demand slowdown in the broader economy.
- Major kharif crops: rice, maize, cotton, sugarcane, groundnut, soybean, tur (arhar), moong, urad
- Agriculture contributes ~17% of India's GDP and employs ~45% of the workforce
- Food inflation and rural wage growth are closely correlated with monsoon performance
- RBI and government budget estimates factor in monsoon forecasts for fiscal planning
Connection to this news: A 70% historical probability of poor monsoon in El Niño years, combined with IMD's below-normal forecast, raises the risk of kharif output shortfall, food inflation pressure, and potential drought-like conditions in vulnerable districts.
Indian Ocean Dipole (IOD) as a Modulating Factor
Not all El Niño years result in monsoon failure. A positive IOD — where the western Indian Ocean is warmer than the eastern Indian Ocean — can counteract El Niño's suppressive influence and provide additional moisture to the Indian subcontinent. The co-occurrence of El Niño with a positive IOD has historically buffered monsoon rainfall.
- Positive IOD can boost Indian monsoon rainfall by 10–20%
- In 1997 (a strong El Niño year), a simultaneous positive IOD helped India avoid severe monsoon deficit
- IMD expects a positive IOD to develop toward the end of the 2026 monsoon season
- The IOD's peak influence is typically September–October, providing only partial relief
Connection to this news: The anticipated positive IOD developing late in 2026 may help avert the worst-case deficient scenario, but June–August remains at elevated risk of below-normal rainfall.
Key Facts & Data
- ~70% of El Niño years since 1980 have coincided with deficient or below-normal Indian monsoon
- IMD 2026 monsoon forecast: 92% of LPA (±5%), classified "below normal"
- LPA (1971–2020 baseline): 868.6 mm for June–September
- El Niño defined as Nino 3.4 SST anomaly ≥ +0.5°C sustained for ≥5 consecutive 3-month periods
- Strong El Niño developing by mid-2026 indicated by multiple global climate models
- Southwest monsoon delivers ~75% of India's annual rainfall
- Agriculture: ~17% of GDP; ~45% of workforce dependent on sector
- Positive IOD expected to develop late 2026 — may partially buffer El Niño impact