La Nina may return from September, global temperatures to stay above average

The World Meteorological Organization (WMO) has said that La Nina conditions may re-emerge from September 2025, potentially reshaping weather and climate patterns across the globe.

In its latest update, WMO noted that while La Niña usually has a cooling effect, global temperatures are still expected to remain above average because of the broader backdrop of human-induced climate change. Rising greenhouse gas emissions, it said, are amplifying extreme weather events and altering rainfall and temperature cycles.

El Niño and La Niña are opposite phases of the El Niño–Southern Oscillation (ENSO). While El Niño is linked to warmer waters in the Pacific Ocean near Peru—often weakening India’s monsoon and making winters milder—La Niña cools those waters, typically strengthening the monsoon and leading to harsher winters.

Since March this year, the Pacific has been in neutral conditions, with sea surface temperatures staying close to average. However, forecasts from WMO’s Global Producing Centres for Seasonal Prediction suggest a 55% chance of La Niña developing between September and November, and about a 60% chance from October to December. The likelihood of El Niño remains low during this period.

“Seasonal forecasts for El Niño and La Niña and their impacts are vital climate intelligence. They save lives and help protect key sectors like agriculture, energy, health, and transport by guiding preparedness,” WMO Secretary-General Celeste Saulo said.

For September to November, WMO projects above-normal temperatures across much of the Northern Hemisphere and significant parts of the Southern Hemisphere. Rainfall patterns are expected to mirror those typically associated with a moderate La Niña.

The update also underlined that ENSO is not the only driver of Earth’s climate, with other patterns—such as the North Atlantic Oscillation, Arctic Oscillation, and Indian Ocean Dipole—also shaping seasonal weather outcomes.