Climate & Environment

El Niño Intensifies, Forecasting Record‑High Pacific Temperatures for Late 2026

By Today News Hours Editorial Desk

Sea‑surface temperatures in the central and eastern tropical Pacific are projected to rise to record levels during October‑November‑December 2026, signalling a strengthening El Niño that will influence global weather patterns and affect economies, ecosystems and communities worldwide. The World Meteorological Organization’s (WMO) Global Seasonal Climate Update states that El Niño will continue to intensify toward its peak in December, likely bringing above‑average temperatures to much of the globe and altering rainfall patterns, which could raise the risk of droughts and floods in various regions.

The Update provides authoritative information on large‑scale climate drivers, including the El Niño‑Southern Oscillation (ENSO), the Indian Ocean Dipole (IOD) and tropical Atlantic sea‑surface temperatures, all of which impact seasonal temperature and rainfall. It complements WMO’s quarterly El Niño/La Niña Update.

"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," said WMO Secretary‑General Celeste Saulo. The near‑certainty figure is a consensus across thirteen national and international centres, based on real‑time exchange of ocean buoy, satellite and radiosonde data coordinated by WMO.

Saulo explained at the Global Heat Forum in Bangkok that El Niño does not add new heat to the planet; it releases heat the ocean has already been storing beneath the surface, which is why a strong event often becomes one of the hottest years measured, as with 2024. "The ocean it's drawing from is the warmest we've ever measured it. There is simply more heat available to release," she said.

Sea‑surface temperature anomalies in the central‑eastern equatorial Pacific, measured by the widely used Niño 3.4 index, increased from an average +1.6 °C above normal in June 2026 to +2.5 °C above normal in August. For October‑November‑December, the seasonal average Niño 3.4 anomaly is forecast to reach approximately +3.7 °C, peaking around December. This is the highest since observations began and exceeds the previous record of +2.6 °C in November 2015‑January 2016.

Other ocean basins also contribute to the outlook. A positive IOD, which can strongly influence rainfall around the Indian Ocean, is expected to peak in October and then decline, with an October‑December seasonal anomaly forecast at about +0.5 °C. Sea‑surface temperatures in the equatorial Atlantic basin are forecast to remain above normal.

The Global Seasonal Climate Update notes that the Earth had the hottest August on record, according to monthly reports from the European Union’s Copernicus Climate Service, the US National Oceanic and Atmospheric Administration and NASA. Global sea‑surface temperature reached an all‑time observed high in August.

The Update predicts an overwhelming likelihood of above‑average (1993‑2009) temperatures across large areas in October‑December, indicating a strong seasonal signal that raises the likelihood of heat extremes and heat‑related impacts. It also forecasts large, coherent shifts in rainfall patterns consistent with a strong El Niño event. The dominant wet signal is above‑normal rainfall across the central and eastern equatorial Pacific east of the Date Line, the Greater Horn of Africa, parts of Central Asia and coastal East Asia, northern parts of the Arabian Peninsula, parts of North America south of 45°N and southeastern South America. In contrast, a broad dry signal is forecast over the western Pacific and the equatorial Atlantic Ocean, stretching across the South Pacific to the southern tip of South America, and over the Indian subcontinent, southern Central America and parts of the Caribbean and northwestern South America.

WMO and its Members have mobilized to help minimize the impacts of El Niño across all sectors of the economy. National Meteorological and Hydrological Services and regional climate outlook forums are engaging regularly with and providing updates to decision‑makers. Recurring updates are being provided across the United Nations system and to humanitarian partners to support preparedness and risk‑management efforts through the WMO Coordination Mechanism.

The El Niño event and the associated forecasted increase in extreme heat are one of the themes of the Global Heat Forum taking place in Bangkok, Thailand, from 6‑9 October. WMO is one of the sponsors of the event, which brings together 600 experts and provides a unique opportunity to transform science into proactive, sustainable and effective solutions.

For further information, contact: - Clare Nullis, WMO media officer, cnullis@wmo.int, +41 79 709 13 97 - Global Communication and Engagement, media@wmo.int