The developing El Niño is expected to strengthen significantly during the coming months, raising the likelihood of major changes in global temperature and rainfall patterns and increasing risks associated with extreme heat, droughts, floods and wildfires.

The World Meteorological Organization says the El Niño event is already firmly established in the tropical Pacific and is forecast to intensify into a very strong event toward the end of 2026.

WMO forecasts indicate a nearly 100 percent likelihood that El Niño will persist through February 2027, giving governments and climate-sensitive sectors an important period to prepare for potential impacts.

Exceptional Pacific Ocean Warming

The central and eastern tropical Pacific is experiencing unusually high sea-surface temperatures.

The Niño 3.4 index, a widely used measure of El Niño conditions, recorded an average anomaly of approximately +1.5°C during May–July 2026 and around +2.0°C in July.

Weekly values subsequently increased further, reaching approximately +2.2°C to +2.6°C above average between late July and mid-August.

Ocean temperatures below the surface were even more unusual, with some areas recording temperatures more than 8°C above average during July and early August.

These ocean conditions provide additional energy for the atmospheric changes associated with El Niño.

Global Temperature Risks

El Niño is one of the strongest natural climate patterns affecting global weather.

When the tropical Pacific becomes unusually warm, it can influence atmospheric circulation thousands of kilometres away.

For September-November 2026, WMO forecasts show an increased likelihood of above-normal temperatures across almost all land areas.

The strongest signals extend across several regions, including Africa, southern Europe, the Arabian Peninsula, South Asia, eastern Asia, Central America, the Caribbean, southern Africa and parts of South America.

Rainfall Patterns Could Shift

The developing El Niño is also expected to alter rainfall patterns.

Some regions may experience increased rainfall and flooding, while others could face below-normal rainfall and drought.

The precise effects differ by location and season, meaning that a strong El Niño does not automatically produce the same type of weather everywhere.

Other climate drivers can also modify its regional effects.

WMO has therefore emphasized the importance of using regional and national forecasts alongside the global El Niño outlook.

Indian Ocean Dipole Adds Another Factor

A positive phase of the Indian Ocean Dipole (IOD) is also expected to develop.

WMO forecasts an average IOD value of approximately 0.9°C for September-November 2026.

The Indian Ocean and Pacific Ocean climate patterns can interact with each other, potentially strengthening or modifying weather effects in different regions.

The combination makes regional forecasting particularly important for countries dependent on seasonal rainfall.

Risks to Agriculture and Water

Changes in rainfall and temperature can have significant consequences for agriculture.

Drought conditions can reduce water availability, damage crops and increase pressure on food supplies.

Excess rainfall, meanwhile, can cause flooding, soil erosion and crop losses.

Water-resource managers also need to prepare for changing river flows, reservoir levels and groundwater conditions.

WMO has therefore emphasized the importance of making seasonal climate information available to agriculture, water and other climate-sensitive sectors.

Health Risks Could Increase

The strengthening El Niño is also becoming a public-health concern.

WMO warned in September that extreme heat, flooding and drought could create additional health risks.

Heat can place pressure on hospitals and increase risks for vulnerable populations, while floods can contribute to injuries, displacement and disease risks.

Drought can also affect water availability, food security and air quality in some regions.

Wildfires and Air Pollution

Higher temperatures combined with dry conditions can increase wildfire risks in some regions.

WMO has warned that parts of the Southern Hemisphere, including southern Africa, South America and Australia, could face heightened heat, drought and wildfire-related risks as the event develops.

Wildfires can create additional public-health problems through smoke and air pollution.

Economic Consequences

El Niño can also affect economies and international supply chains.

Agriculture, fisheries, energy, transport and water systems are among the sectors that can be influenced by changes in weather patterns.

Crop losses can affect food prices, while drought can reduce hydropower production in some regions.

Flooding can damage roads, ports and other infrastructure, potentially disrupting trade.

Governments Prepare for the Event

WMO has called for early action rather than waiting for extreme weather to occur.

National meteorological services are working with governments and climate-sensitive sectors to provide more detailed regional forecasts.

Preparedness measures can include improving early-warning systems, protecting water supplies, adjusting agricultural planning and preparing health services for periods of extreme heat.

Outlook Into 2027

WMO expects El Niño to strengthen toward the end of 2026, with climate impacts potentially continuing into 2027.

The organization stresses that the strength of El Niño alone does not determine the severity of impacts in any individual country.

Local conditions and other climate drivers can significantly alter the outcome.

Nevertheless, the exceptionally warm tropical Pacific and high forecast confidence provide governments with advance information that can be used for preparation.

The developing event demonstrates the importance of climate forecasting in reducing risks to communities, agriculture, water resources, health systems and economies.

With El Niño expected to persist into early 2027, international and national authorities are being encouraged to use the available forecasts to strengthen preparedness before extreme weather risks increase.