El Nino to intensify in July-September, forecasts WMO

• El Nino conditions have developed in the tropical Pacific and are forecast to strengthen rapidly over the coming months, increasing the likelihood of heatwaves, droughts, heavy rainfall and other extreme weather events in many parts of the world, according to the World Meteorological Organisation (WMO).

• WMO’s monthly WMO Global Seasonal Climate Update indicates a rapid development into a strong El Nino event during July-September 2026. 

• The July-September 2026 rainfall outlook reflects a pattern that is consistent with a strengthening El Nino event.

• It is based on multi-model forecasting from WMO partners which indicates a “consistent and significant warming of ocean temperatures” across the central and eastern equatorial Pacific, with seasonal-average sea-surface temperature anomalies expected to exceed 2°C in monitored regions.

• The effects of El Nino vary depending on the intensity, duration, the time of year and also how it interacts with other climate variability modes, including the Indian Ocean Dipole. 

• Not all regions of the world are affected, and even within a region, impacts can be different. 

• Enhanced likelihood of above-normal rainfall is forecast across the central and eastern equatorial Pacific, while below-normal rainfall is more likely across parts of the tropical Indian Ocean, the Indian subcontinent and much of Australia.

• El Nino will also give an extra boost to global temperatures.

• Drier weather patterns are forecast in parts of Indonesia and Southeast Asia during the monsoon season, but wetter conditions are anticipated during the rainy season from September to December in East Africa.

• The El Nino alert has prompted an “unprecedented mobilisation” by WMO, its members worldwide and partners in regional climate centres, to support governments by providing timely forecasts to save lives and protect livelihoods.

What is El Nino and La Nina?

• El Nino and La Nina events are a natural part of the global climate system. They occur when the Pacific Ocean and the atmosphere above it change from their neutral (‘normal’) state for several seasons.

• It occurs on average every two to seven years, and typically lasts nine to 12 months. 

• El Nino, which is the warming of the waters in the Pacific Ocean near South America, is generally associated with the weakening of monsoon winds and dry weather in India.

• It influences weather and storm patterns in different parts of the world. But it takes place in the context of a climate being changed by human activities. 

• It is associated with increased rainfall in the Horn of Africa and the southern US, and unusually dry and warm conditions in Southeast Asia, Australia and southern Africa. 

• La Nina, which is the opposite of El Nino, typically brings good rainfall during the monsoon season.

• These changes in the Pacific Ocean and its overlying atmosphere occur in a cycle known as the El Nino-Southern Oscillation (ENSO). 

• The term ‘El Nino’ translates from Spanish as ‘the boy-child’. Peruvian fishermen originally used the term to describe the appearance, around Christmas, of a warm ocean current off the South American coast. It is now the commonly accepted term to describe the warming of the central and eastern tropical Pacific Ocean. ‘La Nina’ translates as ‘girl-child’ and is the opposite ENSO phase to El Nino.

• However, naturally occurring climate events such as La Nina and El Nino events are taking place in the broader context of human-induced climate change, which is increasing global temperatures, exacerbating extreme weather and climate, and impacting seasonal rainfall and temperature patterns.