El Niño: Heading Toward One of the Most Intense Episodes Ever Measured

The World Meteorological Organization (WMO) is unequivocal: El Niño is now “firmly established” and is expected to keep strengthening in the coming months. According to the update published on September 3, 2026, the probability that the phenomenon will persist through February 2027 is close to 100%, with peak intensity expected toward the very end of the year.

An Episode Already Described as “Firmly Established”

First appearing in June 2026, El Niño crossed the “strong” intensity threshold as early as July, with the Niño 3.4 index (which measures the sea surface temperature anomaly in the equatorial Pacific) already above 2°C. The WMO's seasonal models now anticipate an average anomaly close to 3.6°C for the September-November 2026 period, a level that would rank this episode among the most pronounced ever recorded.

Toward One of the Strongest Episodes Since 1950

At Météo-France, the French national weather service, the assessment is similar. “This episode should rank among the most intense observed since 1950,” summarizes Lauriane Batté, a climatologist at the agency, who relies on Météo-France's 51-model seasonal forecasting system (MF System 9). Ocean temperature anomalies could reach 3°C at the peak of the episode, expected toward the end of 2026.

• Episode start: June 2026
• Intensity by late 2026: “strong to very strong,” comparable to the largest episodes since 1950
• Probability of persistence through February 2027 according to the WMO: close to 100%
• Expected ocean temperature anomaly (Niño 3.4): up to 3 to 3.6°C

What Consequences for France and Europe?

In Europe, the effects of El Niño are “statistically more pronounced in winter” and remain, according to Météo-France, weaker than the underlying trend linked to climate change: the heat waves observed this summer in France, for instance, are not directly linked to this Pacific phenomenon. The clearest impacts will mainly affect France's tropical overseas territories by the end of the year. Still, the broader context of repeated heat waves and drought-stricken waterways already documented in France in recent months fits into the same dynamic of climate disruption that El Niño is temporarily amplifying.

A Warming Context That Amplifies Extremes

It's the combination of the two phenomena that worries climatologists most: an exceptionally strong El Niño episode layered on top of an underlying trend already marked by climate change. The WMO estimates that global average temperature could, in 2026 or 2027, approach or even exceed the 2024 record—the year the symbolic threshold of 1.5°C of warming above pre-industrial levels was crossed. Episodes of extreme heat, such as the one that hit the Fontainebleau forest this summer, or the effects already visible on pollinators, are part of this broader context. At the same time, a positive episode of the Indian Ocean Dipole is also expected, with an average anomaly of 0.9°C over the September-November period, an additional factor likely to influence rainfall patterns in the tropics and indirectly weigh on the economy of certain agricultural regions.

Frequently Asked Questions

What exactly is El Niño?

El Niño is a natural climate phenomenon characterized by abnormal warming of surface waters in the equatorial Pacific, which alters temperature and precipitation patterns worldwide.

When is this episode expected to peak?

According to the WMO and Météo-France, the episode's maximum intensity is expected toward the end of 2026, with a likely persistence through February 2027.

Will France directly experience the effects of El Niño?

The direct effects on France remain more limited than elsewhere: Météo-France points out that El Niño's influence there is statistically more pronounced in winter and, at this stage, remains weaker than the underlying warming trend. France's tropical overseas territories are more significantly affected.

Sources

• Météo-France — El Niño is intensifying: what consequences on a global scale?
• UN News — El Niño is surging, raising fears of months of extreme heat around the world
• We Demain — El Niño 2026-2027: what should we expect in France and around the world?

This article was written with the help of artificial intelligence. Editorial policy