GENEVA, Switzerland (AFP) — The warming El Niño weather phenomenon could return later this year as its cooling opposite La Niña fades away, the United Nations said Tuesday.

The UN’s World Meteorological Organization (WMO) said the recent, weak La Niña was expected to give way to neutral conditions, which could then swing into El Niño before the end of 2026.

La Niña is a naturally occurring climate phenomenon that cools surface temperatures in the central and eastern equatorial Pacific Ocean. It brings changes in winds, pressure and rainfall patterns.

The WMO said there was a 60-percent chance of neutral conditions during the three-month window from March to May, with a 30-percent chance of La Niña conditions, and El Niño at a 10-percent probability.

There is a 70-percent chance of neutral conditions during April to June.

In May to July, the chance of neutral conditions drops back to 60 percent, with the chances of El Niño at 40 percent.

“The WMO community will be carefully monitoring conditions in the coming months to inform decision-making,” said Celeste Saulo, who heads the UN’s weather and climate agency.

“The most recent El Niño, in 2023-24, was one of the five strongest on record and it played a role in the record global temperatures we saw in 2024,” the WMO secretary-general said.

El Niño contributed to making 2023 the second-hottest year on record and 2024 the all-time high.

Above-average temperatures

The WMO underlined that naturally occurring climate events such as La Niña and El Niño take place against the backdrop of human-induced climate change, which is “increasing global temperatures in the long-term, exacerbating extreme weather and climate events, and impacting seasonal rainfall and temperature patterns.”

The US National Oceanic and Atmospheric Administration says there is a 50- to 60-percent chance of El Niño developing during the July-September period and beyond.

“Seasonal forecasts for El Niño and La Niña help us avert millions of dollars in economic losses and are essential planning tools for climate-sensitive sectors like agriculture, health, energy and water management,” Saulo said.

“They are also a key part of the climate intelligence provided by WMO to support humanitarian operations and disaster risk management, and thus save lives,” she said.

The WMO’s latest Global Seasonal Climate update says there is a widespread global signal for above-average land surface temperatures for March to May.

Rainfall predictions in the equatorial Pacific show a lingering La Niña-like pattern, but in other parts of the world the signal is more mixed, it says.