WMO Warns Strengthening El Niño Could Reach Historic Record Highs By December

The El Niño weather phenomenon is set to intensify ahead of its anticipated peak in December, with sea-surface temperatures in the central and eastern tropical Pacific projected to reach historic record levels.

In a global climate update issued on Thursday, October 8, 2026, the World Meteorological Organization (WMO) warned that the rapidly strengthening event will alter weather patterns worldwide, driving above-average temperatures and heightened risks of severe floods and droughts.

WMO Secretary-General Celeste Saulo highlighted that the phenomenon is developing into one of the most intense climate events in modern history.

“El Niño is firmly established and strengthening rapidly. WMO forecasts indicate a near-100 per cent likelihood that it will persist through February 2027, potentially being one of the strongest since at least 1950,” Saulo stated.

Data compiled from 13 international climate research centers shows that the Niño 3.4 sea-surface temperature index surged from 1.6°C above average in June 2026 to 2.5°C in August. The seasonal average for the October–December period is projected to hit 3.7°C above normal—surpassing the previous historic record of 2.6°C set during the 2015–2016 El Niño.

Key Climate Drivers and Atmospheric Impacts:

• Ocean Heat Release: Saulo explained that El Niño releases vast amounts of stored subsurface ocean heat into the atmosphere. Because baseline ocean temperatures are currently at all-time highs, more thermal energy is available to drive extreme global weather.

• Indian Ocean Dipole (IOD): A positive IOD is forecast to peak in October with a 0.5°C seasonal anomaly before tapering off, further influencing rainfall variability around the Indian Ocean basin.

• Equatorial Atlantic Warming: Elevated sea-surface temperatures across the equatorial Atlantic are expected to persist, interacting with Pacific climate drivers to shape broader regional weather patterns.

The WMO urged governments and disaster management agencies to prepare for widespread impacts on agriculture, infrastructure, and public health as shifting rainfall patterns increase vulnerable regions’ exposure to flash floods and prolonged dry spells.