Weak La Niña Likely to Influence Global Weather in Winter 2025–26: WMO Predicts

The World Meteorological Organization (WMO) has issued its latest ENSO (El Niño–Southern Oscillation) Update, predicting a 55% chance of weak La Niña conditions developing during the December 2025 to February 2026 period. While La Niña is often associated with global cooling, the WMO notes that many regions will still experience above-average temperatures, a clear sign of ongoing global warming influencing traditional weather patterns.

What is La Niña?

La Niña is a naturally occurring climate phenomenon marked by a large-scale cooling of sea surface temperatures in the central and eastern Pacific Ocean. It is typically accompanied by shifts in atmospheric circulation, including changes in wind patterns, pressure systems, and rainfall distribution across the tropics and subtropics.

La Niña events can have wide-ranging effects on global weather,

• Drier conditions in parts of the Americas and East Africa
• Heavier rainfall in Southeast Asia, Australia, and parts of southern Africa
• Cooler temperatures in the Pacific but warmer weather in other regions due to overriding climate trends

ENSO Outlook: December 2025 – February 2026

According to the WMO’s Global Producing Centres for Seasonal Prediction,

• As of mid-November 2025, borderline La Niña conditions have been observed.
• There is a 55% chance that La Niña thresholds will be crossed in the December–February season.

The likelihood of ENSO-neutral conditions rises steadily in the following months,

• 65% chance for January–March 2026
• 75% chance for February–April 2026
• There is 0% chance of El Niño development during this period.

This weak La Niña is not expected to produce the extreme disruptions associated with stronger events, but its moderate rainfall and temperature effects will still be significant for climate-sensitive sectors.

Warmer Winter Despite La Niña

Interestingly, despite La Niña’s typical cooling influence, the WMO forecasts above-normal temperatures for much of the Northern Hemisphere and parts of the Southern Hemisphere between December 2025 and February 2026. This is largely attributed to climate change, which continues to raise global average temperatures, altering the outcomes of even well-understood climate cycles.

Rainfall patterns during this period are expected to mimic past weak La Niña years, with certain regions experiencing wetter-than-normal and others facing drier-than-average conditions. However, many areas will likely fall into the “near-normal” category, with probabilistic models suggesting no extreme shifts for most landmasses.

Why These Forecasts Matter

According to WMO Secretary-General Celeste Saulo, these seasonal climate forecasts are crucial for,

• Agriculture: Helping farmers plan crop cycles and manage irrigation.
• Health: Predicting vector-borne disease outbreaks linked to rainfall patterns.
• Transport and energy: Preparing for potential disruptions and demand shifts.
• Humanitarian planning: Mitigating food insecurity or disaster risks in vulnerable regions.

Such data are part of WMO’s climate intelligence efforts, which are increasingly used to save lives and prevent economic losses in a warming world.

Climate Variability in a Changing World

The WMO emphasized that natural cycles like La Niña now occur against the backdrop of long-term climate change, amplifying or offsetting their traditional impacts. Other climate factors—such as the North Atlantic Oscillation, Arctic Oscillation, and Indian Ocean Dipole—are also monitored to provide a fuller seasonal picture through WMO’s Global Seasonal Climate Updates (GSCU).

This comprehensive approach helps governments and sectors adapt to increasingly complex climate realities.