WMO Forecasts Potential La Niña Conditions for Late 2025, Warns of Global Weather Impacts

The World Meteorological Organization (WMO) announced on September 2, 2025, a significant likelihood of La Niña conditions developing between September and November 2025. La Niña, characterized by the cooling of sea surface temperatures in the central and eastern equatorial Pacific Ocean, can influence global weather patterns, leading to increased risks of floods and droughts. Despite its typical cooling effect, global temperatures are projected to remain above average due to ongoing human-induced climate change.

The WMO's latest forecasts indicate a 55% probability of La Niña developing during the September–November period, increasing to about 60% for October–December. This development underscores the complex interplay between natural climate variability and anthropogenic global warming. The anticipated La Niña event could lead to significant weather anomalies across various regions, impacting sectors such as agriculture, energy, health, and transport.

Understanding La Niña

La Niña is a climate phenomenon that forms part of the El Niño-Southern Oscillation (ENSO) cycle. It is characterized by unusually cold ocean temperatures in the Equatorial Pacific, in contrast to El Niño, which is associated with warmer ocean temperatures. La Niña events can last from several months to a few years and typically occur every 2 to 7 years. The cooling of the Pacific Ocean influences atmospheric circulation patterns, leading to significant changes in weather and climate across the globe.

Potential Global Impacts of La Niña

The development of La Niña conditions can have widespread effects on global weather patterns:

• Increased Rainfall and Flooding: Regions such as Southeast Asia, Australia, and parts of South America may experience above-average rainfall, leading to an increased risk of flooding.

• Drought Conditions: Conversely, areas like the southwestern United States, parts of Africa, and the Middle East might face drier conditions, heightening the risk of droughts.

• Hurricane Activity: La Niña can influence tropical cyclone activity. For instance, the Atlantic hurricane season may see increased activity, while the Pacific basin might experience a decrease.

• Temperature Variations: Some regions may experience cooler-than-average temperatures, while others could see warmer conditions, depending on local atmospheric responses.

Implications for Various Sectors

The potential return of La Niña has significant implications across multiple sectors:

• Agriculture: Farmers may need to prepare for altered growing conditions, such as increased rainfall leading to waterlogging or drought conditions affecting crop yields.

• Energy: Energy demand could fluctuate with temperature changes; for example, colder winters may increase heating needs, while droughts could impact hydroelectric power generation.

• Health: Changes in weather patterns can influence the spread of vector-borne diseases like malaria and dengue fever, as well as impact food security and nutrition.

• Transport: Extreme weather events associated with La Niña, such as floods and storms, can disrupt transportation networks, affecting the movement of goods and people.

Historical Context and Comparisons

La Niña events have occurred periodically, with notable instances in recent decades. Each event varies in intensity and duration, leading to different global impacts. Comparing the current forecast with past events can provide insights into potential outcomes and inform preparedness strategies.

Statements from the World Meteorological Organization

In their announcement, the WMO highlighted the importance of monitoring and preparedness:

"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."

Conclusion

The WMO's forecast of a potential return of La Niña conditions between September and November 2025 serves as a critical reminder of the interconnectedness of oceanic and atmospheric systems and their profound impact on global weather patterns. Stakeholders across sectors are advised to stay informed and take proactive measures to mitigate potential adverse effects associated with La Niña.