La Niña May Return, but Global Warming to Persist: WMO

The probability of La Niña returning between now and December is between 55 and 60 per cent, according to the World Meteorological Organization (WMO).

The cooling climate phenomenon known as La Niña could return between now and November, but it will not halt the trend of rising global temperatures caused by human activity, UN weather experts said on Tuesday.

Latest data from the World Meteorological Organization (WMO) indicates a 55 per cent likelihood that sea surface temperatures in the equatorial Pacific will cool to La Niña levels from September to November.

About 90 per cent of the excess heat from global warming is stored in the ocean, making ocean heat content a critical indicator of climate change.

“For October to December 2025, the probability of La Niña conditions slightly increases to about 60 per cent. There is little chance of El Niño developing during September to December,” the WMO said in an update.

According to the UN agency, there is a smaller chance (45 per cent) that Pacific temperatures will remain neutral, as they have for the past six months, when neither the cooling La Niña nor its opposite, the warming El Niño, caused unusual spikes or dips in sea surface temperatures.

The WMO’s forecast for the El Niño–Southern Oscillation phenomenon is an important climate intelligence tool which could “save thousands of lives when used to guide preparedness and response actions”, said WMO Secretary-General Celeste Saulo.

The information could also translate into millions of dollars in savings across agriculture, energy, health and transport, she added.

While La Niña and El Niño significantly shape climate by altering ocean surface temperatures and influencing winds, pressure and rainfall patterns, human-induced climate change is still “increasing global temperatures, exacerbating extreme weather, and impacting seasonal rainfall and temperature patterns”, the WMO noted.

Each year of the past decade has been among the ten warmest on record, the UN agency warned earlier this year, with 2024 being the hottest yet, marked by “exceptional land and sea surface temperatures and ocean heat”.

Citing six international datasets, the WMO said that the global average surface temperature was 1.55°C (34.79°F) above the 1850–1900 average.

“Blazing temperatures in 2024 require trail-blazing climate action in 2025,” said UN Secretary-General António Guterres at the time. “There is still time to avoid the worst of climate catastrophe. But leaders must act – now,” he insisted.

Other key climate phenomena that influence global temperature include the North Atlantic Oscillation, the Arctic Oscillation and the Indian Ocean Dipole. Their impact on surface temperatures and rainfall is monitored by the WMO and published in regular Global Seasonal Climate Updates (GSCU).

The latest update indicates that from September to November, temperatures are expected to be above normal across much of the Northern Hemisphere and large parts of the Southern Hemisphere.

Rainfall predictions are expected to align with patterns typically observed during a moderate La Niña, the WMO assessment noted.