Intensifying El Niño Sets Pacific Temperature Record and Raises Prospects of Hottest Year

An intensifying El Niño has already produced the highest sea-surface temperatures on record in a key monitoring region of the tropical Pacific and is on track to rank among the strongest events ever observed. Carlo Buontempo, director of the EU’s Copernicus Climate Change Service, said the pattern could help make 2026 or 2027 the hottest year globally.

Copernicus reported that temperatures in the Niño 3.4 region reached 29.70 degrees Celsius in September, exceeding the peaks recorded during the strong El Niño events of 1982–83, 1997–98, and 2015–16. Daily anomalies in the same region passed the previous record set in November 2015. Japan’s Meteorological Agency stated that the current event had reached its strongest intensity on record.

El Niño is the warm phase of a natural cycle that raises sea temperatures in the equatorial Pacific and alters weather patterns worldwide. It does not add new heat to the climate system; it releases heat already stored in the ocean. The current episode began in June and is expected to peak later this year or early next. Forecasters project monthly anomalies could reach around 4 degrees Celsius above average at their maximum.

Global average sea-surface temperatures also set a September record at 21.05 degrees Celsius. Surface air temperatures in September ranked as the second-hottest on record after a record August. Buontempo noted that if the event follows past patterns, 2026 could become the warmest year measured, with 2027 potentially hotter still.

The World Meteorological Organization has described the episode as a very strong, or Super, El Niño and said there is a near-100 percent chance it will persist into early 2027. NOAA has indicated a high probability that the event will exceed the strength of any El Niño recorded since 1950.

Strong El Niño events are associated with increased risks of drought in some regions and flooding in others. They can reduce rainfall in parts of Australia, Indonesia, and southern Africa while increasing it in parts of the Americas. The current event has already been linked to a weak Indian monsoon, elevated wildfire risk in Indonesia, and pressure on sugar and coffee production in Brazil.

The combination of a record-strong El Niño and the long-term rise in baseline temperatures from greenhouse-gas emissions increases the likelihood of extreme heat and related impacts over the next 18 months. Scientists caution that the final ranking of the event will not be known until it peaks and that global temperature records depend on the precise timing of that peak relative to the calendar year.

Monitoring agencies will continue to track ocean temperatures and atmospheric responses through the end of 2026. The data already in hand show that the Pacific is warmer, earlier in the cycle, than during any previous El Niño in the instrumental record.