Climate

'Possible record global heat'. El Niño is coming back: when will it develop and how much will it affect

Climatologist Pasini: 'We still have to see how strong it will be, but it will probably still exceed that critical threshold of the Paris Agreement'

by Lorenzo Pace

25 April 2026

2' min read

Translated by AI

Versione italiana

2' min read

Translated by AI

Versione italiana

The El Niño phenomenon is about to return and with it, in some parts of the world, extreme weather events, from heat waves to floods. Its influence, however, will be global, with widespread temperature increases that could last well into winter.

What is El Niño

El Niño is a climatic phenomenon that develops in the tropical Pacific Ocean. It is explained by Antonello Pasini, a climatological physicist at the CNR and scientific director of the Milan Duomo Meteorological Observatory.

This is a cyclical event, alternating with a cold phase (La Niña) and occurring every 2 to 7 years. The last time it occurred was between 2023 and 2024, years in which record temperatures were reached, above the critical threshold of 1.5 degrees (identified with the Paris Agreement) compared to pre-industrial levels.

But how does it work? Sea surface temperatures rise by at least 0.5 °C for more than five months, causing different meteorological reactions around the world.

Heat waves and floods

In Australia, for example, the consequences are 'direct'. It means heat waves and droughts. The same goes for South America, in countries such as Peru, where 'floods and heavy rains' will arrive. In this sense, direct effects in Europe will be more difficult to see. What will certainly come is an increase in temperatures.

Why we talk about Super El Niño

But how much? As mentioned, it is a cyclical event that occurred even a few years ago. However, its impact is not always equal: 'It depends on the strength,' Pasini explains, 'and there are projections showing that it should be quite strong.

Only signals at the moment: since it will really start to develop between May and June/July, it may be premature to speak of an exceptionally hot wave even now. Of one thing, however, Pasini is almost certain: 'We will probably still exceed that critical threshold of the Paris Agreement. We can expect a record global average'.

This, of course, is also due to the factor of the growing human influence over the years. Emissions will also help extend the power of the phenomenon in the following months.

Not just summer

It is not certain, in fact, that this will happen in the summer. 'We are now entering the new cycle,' the climatologist points out, 'but strong El Niño will occur in the summer, in the autumn, and could perhaps even last into the first half of next year.