The tropical Pacific is warming rapidly and scientists no longer have any doubts: El Niño is back. And it could become one of the most intense ever observed. This is confirmed by the latest updates from the European Center for Medium-Range Weather Forecasts (ECMWF), which show an increasingly marked anomaly in ocean surface temperatures in the equatorial Pacific.
According to climate scientists, 2026 could evolve towards a real “super El Niño”, a scenario capable of altering the global climate, amplifying extreme events and pushing world temperatures further upwards.
The picture emerges as the Copernicus Climate Change Service (C3S) certifies that April 2026 was the third warmest April on record globally, with an average temperature of 14.89°C, equal to +1.43°C compared to pre-industrial levels.
The “super El Niño”
Climatologists and meteorologists have been following the evolution of the phenomenon for months. Already at the beginning of April, the ECMWF analyses, in line with those of NOAA and the IRI of Columbia University, indicated a very high probability of the development of El Niño. Now the latest updates further strengthen the signal: the event is considered practically certain and could take on historic dimensions.
This is explained by Luca Lombroso, meteorologist at Meteored Italia, who describes the functioning of the ECMWF monitoring through the “Niño 3.4 SST Anomaly” product, based on ERA5 data relating to sea surface temperature in the tropical Pacific.
The system uses a “plume” graph, i.e. a set of ensemble simulations: each line represents a possible evolution in the key areas of the Pacific called Niño 1+2, 3, 3.4 and 4. When the lines remain close to each other, it means that the models show high agreement and therefore greater forecast reliability.
The official threshold for declaring El Niño is exceeded when the sea temperature anomaly in the Niño 3.4 area stably exceeds +0.5°C compared to the climatological norm. Between +0.5 and +1°C we speak of a weak event. But this time the numbers are much higher. According to the ECMWF update, the threshold will be exceeded in a stable manner between May and June, with persistence for at least three months. The official start of the event could therefore be declared as early as June or July.
Subsequent simulations indicate an impressive acceleration: between July and August the anomalies could reach +1.5/+2°C, while between September and November many scenarios show values between +2.5 and +3°C, with peaks up to +4°C. Exceptional values, even higher than the great El Niños of 1984, 1997 and 2015.
For experts, we talk about “super El Niño” when the sea temperature anomaly exceeds +2°C for at least three consecutive months.
April 2026 among the hottest ever
The new warning comes as the oceans are already showing off-scale signals. According to the Copernicus climate bulletin, in April 2026 the average sea surface temperature in the extra-polar oceans reached 21°C – the second highest value ever recorded for the month.
Marine temperatures have reached record levels in a vast band from the central equatorial Pacific to the western coasts of the United States and Mexico, in the presence of strong marine heat waves.
The data is considered particularly important because the warming of the oceans represents the “engine” of El Niño: the more the tropical Pacific accumulates heat, the more the phenomenon tends to strengthen and influence global atmospheric circulation.
In Europe, the month was the tenth warmest April on record, but with very stark contrasts: temperatures well above average in Spain and southwestern Europe, while eastern Europe experienced colder than normal conditions.
And in Italy?
As for Europe and Italy, the direct effects of El Niño remain more difficult to predict.
The so-called “teleconnections“, i.e. the atmospheric connections between the Pacific and the Euro-Mediterranean area, are in fact very complex. According to experts, no immediate direct effects are expected in the summer of 2026, but the phenomenon could still influence the behavior of the African and Azores anticyclones, accentuating the heat anomalies.
In any case, the latest ECMWF seasonal projections already indicate a summer that is most likely warmer than average, with thermal anomalies between +1 and +2°C and the most important consequences could however emerge between autumn and winter, especially if the phenomenon were to really evolve into a super El Niño. In that case there could be strong undulations in the jet stream, persistent atmospheric blocking and phases of intense precipitation alternating with long dry periods.
In short, all scenarios that scientists are observing with increasing attention, because they could translate into unprecedented recent meteorological events on a global and European scale.
