Enviro News Asia, Geneva — The World Meteorological Organization (WMO) has warned that a strengthening El Niño event could drive record-high sea-surface temperature anomalies in the central and eastern tropical Pacific during October–December 2026, increasing the risk of extreme heat, drought, and flooding in different parts of the world.
In its Global Seasonal Climate Update released on October 8, the WMO forecast that El Niño would continue intensifying ahead of a potential peak in December. The organization also projected a near-100% likelihood that the climate phenomenon would persist through February 2027, potentially making it one of the strongest events since at least 1950.
“El Niño is firmly established and strengthening rapidly,” WMO Secretary-General Celeste Saulo said, highlighting the potential for widespread climate impacts on communities, ecosystems, and economies.
The WMO’s assessment draws on forecasts from 13 national and international climate prediction centres, supported by the exchange of ocean buoy, satellite, and atmospheric observation data.
Pacific Ocean Temperatures Set to Rise
The Niño 3.4 index, a widely used measure of sea-surface temperature anomalies in the central-eastern equatorial Pacific, rose from an average of 1.6°C above normal in June 2026 to 2.5°C above normal in August.
For October–December, the seasonal average anomaly is forecast to reach approximately 3.7°C, with a potential peak around December. If realized, this would exceed the previous record of 2.6°C recorded during November 2015–January 2016.
El Niño is part of the El Niño–Southern Oscillation (ENSO), a natural climate pattern that influences weather systems around the world. It can alter atmospheric circulation and shift rainfall patterns, increasing the likelihood of heat extremes and other climate-related hazards.
The WMO also highlighted unusually warm ocean conditions beyond the Pacific. A positive Indian Ocean Dipole is expected to peak in October before weakening, with its October–December seasonal anomaly forecast at approximately 0.5°C. Meanwhile, sea-surface temperatures in the equatorial Atlantic are expected to remain above normal.
Global Heat and Rainfall Patterns Expected to Shift
The WMO outlook indicates a strong likelihood of above-average temperatures across large areas of the world during October–December. The forecast signals an increased risk of heat extremes, although it does not mean every location will experience warmer-than-average conditions every day.
Rainfall patterns are also expected to shift significantly. Wetter-than-normal conditions are forecast to be more likely across the central and eastern equatorial Pacific, the Greater Horn of Africa, parts of Central Asia and coastal East Asia, northern areas of the Arabian Peninsula, parts of North America south of 45° north latitude, and southeastern South America.
In contrast, drier-than-normal conditions are forecast across the western Pacific and equatorial Atlantic, extending through parts of the South Pacific toward the southern tip of South America. The Indian subcontinent, southern Central America, parts of the Caribbean, and northwestern South America are also expected to face an increased likelihood of below-average rainfall.
These seasonal forecasts indicate probabilities rather than certainty. The WMO stressed that its global outlook complements, rather than replaces, national and local weather forecasts.
Climate Agencies Strengthen Preparedness
The WMO and its member countries are coordinating efforts to reduce El Niño’s potential impacts across economic sectors and communities. National meteorological and hydrological services, together with regional climate outlook forums, are providing regular updates to decision-makers.
The organization is also sharing recurring assessments across the United Nations system and with humanitarian partners to support preparedness and risk management through the WMO Coordination Mechanism.
El Niño and the associated risk of extreme heat were among the key topics at the Global Heat Forum, held in Bangkok, Thailand, from October 6 to 9, 2026. The event brought together approximately 600 experts to discuss ways to translate climate science into practical and sustainable solutions.
The WMO emphasized the importance of using seasonal climate information to strengthen early warning systems, prepare for potential water shortages and floods, and protect communities from extreme heat.
As the event develops toward its anticipated December peak, governments and communities will need to monitor updated forecasts and prepare for regional differences in temperature and rainfall conditions. (*)
