What Happened
- The World Meteorological Organization (WMO) confirmed that the 2024-25 La Nina event has significantly weakened and the tropical Pacific is transitioning to ENSO-neutral conditions.
- WMO's Global Producing Centres placed the probability of El Nino emerging between May and July 2026 at approximately 40%, up sharply from 10% projected earlier.
- Observations of increasing subsurface warm water in the central Pacific Ocean — a leading indicator of El Nino development — signal that conditions are ripening for a potential El Nino in the second half of 2026.
- Above-average land surface temperatures are forecast across large parts of the globe for the March-May 2026 period, consistent with the underlying global warming trend amplified by the loss of La Nina's cooling effect.
- Meteorological agencies worldwide, including India's IMD and Skymet Weather, have begun factoring in rising El Nino probability when producing long-range monsoon forecasts for the 2026 kharif season.
Static Topic Bridges
La Nina: Mechanism, Duration, and Global Impacts
La Nina is the cooling phase of the El Nino-Southern Oscillation (ENSO) cycle, characterized by below-average sea surface temperatures in the central and eastern tropical Pacific Ocean. It arises when easterly trade winds strengthen, pushing warm water westward toward the Indo-Pacific region and allowing cold water to upwell along the South American coast and the central Pacific. La Nina typically brings above-normal rainfall to Australia, South Asia, and Southeast Asia, and below-normal rainfall to parts of the Americas.
- La Nina is declared when Nino 3.4 region SSTs drop 0.5°C below the 30-year climatological average for at least 5 consecutive three-month periods.
- Duration: typically 9-12 months; "double-dip" or multi-year La Ninas (as in 2020-23) can persist for 2-3 years.
- The 2024-25 La Nina was classified as "weak" — SST anomalies did not significantly exceed the -0.5°C threshold.
- La Nina is generally associated with above-normal Indian monsoon rainfall (good for agriculture, but also heightens flood risk in some regions).
- Global effects: increased Atlantic hurricane activity; drought in southern South America and southern Africa; stronger monsoon over South Asia.
Connection to this news: The weakening and imminent end of the 2024-25 La Nina removes the climate driver that has been supporting above-normal rainfall conditions globally. Its replacement — first by ENSO-neutral and potentially by El Nino — creates a fundamentally different and more uncertain climate backdrop for the 2026 monsoon season.
Indian Ocean Dipole (IOD) as a Monsoon Moderator
The Indian Ocean Dipole (IOD) — sometimes called the "Indian Nino" — is an ENSO-like climate oscillation within the Indian Ocean itself. It is defined by the difference in sea surface temperatures between the western Indian Ocean (Arabian Sea region) and the eastern Indian Ocean (Bay of Bengal / Indonesian region). A positive IOD (warmer western, cooler eastern Indian Ocean) supports stronger monsoon rainfall over India, often offsetting the weakening effect of El Nino.
- IOD is measured by the Dipole Mode Index (DMI).
- Positive IOD events: associated with above-normal Indian monsoon rainfall (e.g., 2019 — despite weak El Nino, monsoon was normal due to positive IOD).
- Negative IOD events: associated with drought in India, Australia, and East Africa.
- The 2019 positive IOD was a landmark case of IOD modulating El Nino's influence on the Indian monsoon.
- IOD events are partially independent of ENSO, giving Indian Ocean warming patterns their own role in monsoon determination.
- IMD includes IOD forecasts alongside ENSO in its long-range monsoon prediction models.
Connection to this news: Even if El Nino emerges by mid-2026, a concurrent positive IOD — which is independently driven by Indian Ocean dynamics — could partially or fully offset El Nino's drying influence on the Indian monsoon, making the IOD evolution in April-June 2026 a critical variable to monitor.
Disaster Management and Drought-Proofing in India
Drought is classified as a natural disaster under the Disaster Management Act, 2005. The National Disaster Management Authority (NDMA) has issued guidelines for drought risk reduction and management. Given India's reliance on rain-fed agriculture (over 60% of cultivated area is rain-fed), ENSO-related monsoon deficits are among the most significant systemic risks to rural livelihoods, food prices, and national food security.
- India's drought classification: Meteorological drought (rainfall deficiency), Hydrological drought (groundwater/river depletion), Agricultural drought (soil moisture deficiency), Socio-economic drought (production failure affecting incomes).
- The Manual for Drought Management (2016, MoAFW) provides the standard protocol for drought declaration and relief measures at state and district levels.
- Pradhan Mantri Fasal Bima Yojana (PMFBY), launched 2016: provides crop insurance coverage against natural calamities including drought; a key instrument for farmer income protection under El Nino risk.
- Mahatma Gandhi National Rural Employment Guarantee Act (MGNREGA) acts as a drought relief mechanism by providing guaranteed employment in drought-affected rural areas.
- India's National Food Security Act, 2013 provides legal entitlement to subsidized food grains (5 kg/person/month) for 81.35 crore beneficiaries — a social protection buffer against food price shocks from drought.
Connection to this news: A potential El Nino in the second half of 2026 creates the precise climate risk scenario for which India's drought management framework, crop insurance scheme, and food security programs are designed — making this WMO forecast operationally significant for government preparedness planning.
Key Facts & Data
- La Nina status (March 2026): Weakening significantly; ENSO-neutral expected by March-May 2026
- El Nino probability for May-July 2026: ~40% (up from ~10% earlier)
- ENSO-neutral probability: 60-70% for March-June 2026
- Leading indicator of El Nino: subsurface warm water accumulation in central Pacific
- WMO: World Meteorological Organization — UN specialized agency, 193 member states
- La Nina declaration threshold: SST anomaly ≤ -0.5°C in Nino 3.4 region, 5 consecutive three-month periods
- El Nino declaration threshold: SST anomaly ≥ +0.5°C in Nino 3.4 region, 5 consecutive three-month periods
- India's rain-fed agriculture: over 60% of cultivated area dependent on monsoon
- Key moderating factor: Indian Ocean Dipole (IOD) — positive phase can offset El Nino's drying influence
- Crop insurance mechanism: Pradhan Mantri Fasal Bima Yojana (PMFBY), 2016
- India drought law: Disaster Management Act, 2005; NDMA Drought Guidelines
- 2023-24 El Nino: kharif rice production fell ~3.79%; above-normal heat events; 2024 confirmed as warmest year on record