The World Meteorological Organisation (WMO) is warning that La Niña may return to impact weather and climate patterns beginning September onwards. The UN organisation however says that “despite the temporary cooling influence of La Niña, temperatures are still expected to be above average for much of the world.”

According to the latest forecasts from the WMO Global Producing Centres for Seasonal Prediction, there is a 55% chance for sea surface temperatures in the equatorial Pacific to cool to La Niña levels, and a 45% chance for them to remain at ENSO-neutral levels during the upcoming September–November 2025 period. “For October, November to December 2025, the probability of La Niña conditions slightly increases to about 60%.”

“Seasonal forecasts for El Niño and La Niña and their associated impacts on our weather are an important climate intelligence tool. They translate into millions of dollars of economic savings for key sectors like agriculture, energy, health and transport and have saved thousands of lives when used to guide preparedness and response actions,” said WMO Secretary-General Celeste Saulo.

The WMO explains that, La Niña refers to the periodic large-scale cooling of the ocean surface temperatures in the central and eastern equatorial Pacific Ocean, coupled with changes in the tropical atmospheric circulation, including changes in winds, pressure and rainfall patterns. Typically, La Niña brings climate impacts that are the opposite of El Niño, especially in tropical regions.

“However, naturally occurring climate events such as La Niña and El Niño are taking place in the broader context of human-induced climate change, which is increasing global temperatures, exacerbating extreme weather, and impacting seasonal rainfall and temperature patterns,” says the statement.

While the El Niño-Southern Oscillation (ENSO) is a key driver of global climate patterns, it is not the only factor shaping the Earth’s climate. Together with ENSO, the other drivers  influencing key climate variability patterns include: the North Atlantic Oscillation, the Arctic Oscillation and the Indian Ocean Dipole (IOD).

The latest Update says that for September to November, temperatures are expected to be above normal in much of the Northern hemisphere and large parts of the southern hemisphere.