WMO Warns of Possible La Niña Return Amid Rising Global Temperature Trends

The World Meteorological Organization (WMO) has issued its latest El Niño/La Niña update, warning that La Niña conditions could return as early as September 2025, influencing global weather and climate patterns. Despite La Niña’s typical cooling effect, forecasters stress that above-average global temperatures are expected to persist due to the long-term impacts of climate change.

ENSO Outlook: Neutral Shifts Toward La Niña

Since March 2025, the Pacific Ocean has remained under ENSO-neutral conditions, with sea surface temperatures in the equatorial Pacific hovering near long-term averages. However, forecasts from WMO’s Global Producing Centres for Seasonal Prediction suggest that these neutral conditions may give way to La Niña in the coming months.

• For September–November 2025, there is a 55% chance of La Niña and a 45% chance of neutral conditions.

• For October–December 2025, the probability of La Niña increases slightly to 60%, while the chance of El Niño developing remains near zero.

This indicates a growing likelihood of moderate La Niña conditions toward the end of 2025.

Why It Matters: ENSO’s Global Influence

The El Niño-Southern Oscillation (ENSO) is one of the most influential climate phenomena, shaping rainfall, storm activity, droughts, and temperature extremes across much of the globe.

• El Niño is linked to warming of the equatorial Pacific and often brings drought to some regions and heavy rainfall to others.

• La Niña, its counterpart, involves large-scale cooling of Pacific waters, altering wind, pressure, and rainfall patterns in ways that typically reverse El Niño’s impacts, especially in the tropics.

“La Niña and El Niño seasonal forecasts are an important climate intelligence tool,” said WMO Secretary-General Celeste Saulo. “They help save lives and reduce economic losses by guiding preparedness across agriculture, energy, health, and transport sectors.”

Climate Change Context

While ENSO remains a powerful natural driver of variability, WMO emphasized that it operates within the larger framework of human-induced climate change. Rising greenhouse gas concentrations are:

• Pushing global average temperatures to record highs.

• Amplifying extreme weather events, such as heatwaves, droughts, and floods.

• Altering rainfall distribution and seasonal climate predictability.

Thus, even during La Niña periods, when cooling might be expected, the baseline warming trend ensures that most regions will still experience above-normal temperatures.

Global Seasonal Climate Update (GSCU)

To give a fuller picture, WMO supplements ENSO updates with its Global Seasonal Climate Updates (GSCU), which track additional large-scale climate drivers such as:

• The North Atlantic Oscillation (NAO).

• The Arctic Oscillation (AO).

• The Indian Ocean Dipole (IOD).

These updates also monitor temperature and precipitation anomalies, helping refine regional forecasts.

The latest GSCU projects that from September to November 2025:

• Temperatures will be above average across most of the Northern Hemisphere and much of the Southern Hemisphere.

• Rainfall patterns will resemble those typical of moderate La Niña episodes, including wetter conditions in parts of Southeast Asia and Australia, and drier weather in eastern Africa and South America.

Implications for Decision-Makers

The WMO stresses that seasonal forecasts are critical for policymakers and communities, enabling proactive disaster risk management and efficient planning. For example:

• Agriculture: Farmers can adjust planting schedules based on rainfall forecasts.

• Health: Authorities can prepare for potential outbreaks of waterborne diseases linked to flooding.

• Energy: Power utilities can anticipate shifts in hydroelectric generation or cooling demand.

• Transport and logistics: Anticipating weather disruptions can save millions in avoided losses.

Looking Ahead

As the likelihood of La Niña grows, the WMO continues to urge governments to integrate climate forecasts into planning and response systems. While ENSO events are temporary, the long-term influence of climate change means above-average global temperatures and more volatile extremes are here to stay.

“Preparing for La Niña is not just about weather—it’s about safeguarding economies, health, and livelihoods,” Saulo said. “Climate services are our strongest defense against growing risks.”