El Nino may return by mid-2026 amid warming seas, says WMO

The World Meteorological Organization (WMO) has signalled a clear shift in equatorial Pacific conditions: sea-surface temperatures (SSTs) are rising rapidly,...

What Happened

The World Meteorological Organization (WMO) has signalled a clear shift in equatorial Pacific conditions: sea-surface temperatures (SSTs) are rising rapidly, indicating that El Nino conditions are likely to emerge by May–July 2026.
ENSO (El Nino-Southern Oscillation) is currently in a neutral phase, following the conclusion of the 2025-26 La Nina episode. Near-average SSTs are observed in the central and eastern equatorial Pacific, but subsurface heat content is increasing.
Multiple climate forecast models — including those from WMO, Japan Meteorological Agency (JMA), and China's National Climate Centre — are converging on a 61 percent probability of El Nino emerging in the May–July 2026 window, potentially persisting through at least the end of 2026.
Japan's meteorological bureau places the probability of El Nino emerging in northern hemisphere summer 2026 at 70 percent.
Once established, the event could intensify into a strong El Nino — with some models pointing to SST anomalies exceeding the thresholds associated with significant global climate disruption.
Land surface temperatures are expected to be above normal nearly everywhere during an El Nino period; the signal is especially strong over southern North America, Central America, the Caribbean, Europe, and northern Africa.
Rainfall patterns are expected to turn uneven: drier than normal conditions projected across South Asia, Southeast Asia, and parts of Africa; wetter conditions in parts of South America and the Horn of Africa.
A caveat persists: the spring predictability barrier (the difficulty of making confident ENSO forecasts across the March–May period) means confidence in exact timing and intensity improves significantly after April–May 2026.

Static Topic Bridges

ENSO: The El Nino-Southern Oscillation System

ENSO is a periodic oscillation of sea-surface temperatures and atmospheric pressure across the equatorial Pacific Ocean. It is one of the most powerful natural climate drivers on Earth, influencing rainfall, temperature, and storm patterns across multiple continents simultaneously.

El Nino phase: Anomalous warming of SSTs in the central and eastern equatorial Pacific; associated with weakening of trade winds, redistribution of rainfall, and warming of global mean temperatures.
La Nina phase: Anomalous cooling of SSTs in the same region; associated with strengthening of trade winds and opposite precipitation anomalies (wetter South Asia, drier Americas).
ENSO-neutral: SSTs remain near the long-term average; neither phase is active.
ENSO cycles typically last 9 to 12 months but can extend beyond two years.
The canonical El Nino threshold is a 3-month running mean SST anomaly of +0.5°C or more in the Nino 3.4 region (5°N–5°S, 170°W–120°W) for at least five consecutive overlapping seasons.
A "strong" El Nino is generally associated with SST anomalies exceeding +1.5°C to +2.0°C in the Nino 3.4 region.

Connection to this news: The WMO forecast signals a transition from the current neutral phase to El Nino conditions in mid-2026. The speed of SST rise and subsurface heat content build-up are early indicators that the forthcoming event may be significant in strength.

World Meteorological Organization (WMO)

WMO is a United Nations specialized agency for meteorology (weather and climate), operational hydrology, and related geophysical sciences. Established in 1950, it coordinates global weather observation, data sharing, and climate monitoring.

WMO coordinates the Global Climate Observing System (GCOS), including networks of weather stations, ocean buoys (Argo float network, TAO/TRITON buoy array in the Pacific), and satellites that provide the SST data underpinning ENSO forecasts.
WMO publishes regular ENSO updates — typically every three months — based on ensemble forecasts from multiple national meteorological services.
The Global Seasonal Climate Update (GSCU), issued by WMO, is the primary international reference for seasonal climate outlooks.
WMO's 2023 El Nino advisory correctly forecast the 2023-24 event, which became the strongest on record at the time.

Connection to this news: The WMO's current ENSO update, with its 61 percent El Nino probability for May–July 2026, carries significant policy weight for agriculture ministries, disaster management agencies, and water resource planners across South Asia.

El Nino and the Indian Monsoon

India's southwest monsoon (June–September), which delivers approximately 70 percent of the country's annual rainfall, is structurally sensitive to ENSO conditions. El Nino years are associated with reduced monsoon rainfall in India, while La Nina years tend to produce excess rainfall.

Historical data shows that approximately 60–70 percent of El Nino years since 1871 have produced below-normal monsoon rainfall in India.
The Indian Meteorological Department (IMD) uses ENSO phase, Indian Ocean Dipole (IOD), and other predictors in its seasonal monsoon forecast model.
A positive Indian Ocean Dipole (warmer western Indian Ocean) can partially offset El Nino's drying influence on the Indian monsoon.
Below-normal monsoon conditions reduce kharif crop production (rice, pulses, oilseeds, cotton, sugarcane) and replenishment of reservoirs that supply rabi irrigation.

Connection to this news: With El Nino likely to establish by June–July 2026 — precisely when the Indian monsoon is at its peak — the risk of a deficit monsoon in 2026 is materially elevated. India's monsoon forecast for 2026 anticipates rainfall at approximately 70–90 percent of the Long Period Average.

Key Facts & Data

El Nino onset probability (May–July 2026): 61 percent (WMO multi-model ensemble)
Japan Meteorological Agency estimate: 70 percent probability of El Nino in northern hemisphere summer 2026
ENSO-neutral probability (April–June 2026): 80 percent (as of April 2026 assessment)
Current ENSO status: Neutral, following end of 2025-26 La Nina
El Nino threshold: SST anomaly of +0.5°C or more in Nino 3.4 region for five consecutive overlapping 3-month periods
Strong El Nino threshold: SST anomaly of +1.5°C to +2.0°C
WMO established: 1950 (UN specialized agency since 1951)
WMO member states: 193 countries and territories
Spring predictability barrier: forecasts made before April–May have higher uncertainty for ENSO onset timing
Global mean temperature impact: El Nino years are typically 0.1–0.2°C warmer than ENSO-neutral years
India monsoon rainfall during El Nino years: approximately 60–70 percent of historical El Nino years produced below-normal monsoon