El Niño conditions are underway in the tropical Pacific, according to the World Meteorological Organization (WMO). 

An update from the WMO says El Niño conditions have developed in the tropical Pacific for the first time in seven years, setting the stage for a likely surge in global temperatures and disruptive weather and climate patterns.

The experts predict a 90 per cent probability of the El Niño event continuing during the second half of 2023. It is expected to be at least of moderate strength. 

“The onset of El Niño will greatly increase the likelihood of breaking temperature records and triggering more extreme heat in many parts of the world and in the ocean,” says WMO Secretary-General Professor Petteri Taalas.

“The declaration of an El Niño by WMO is the signal to governments around the world to mobilise preparations to limit the impacts on our health, our ecosystems and our economies,” he said. 

“Early warnings and anticipatory action of extreme weather events associated with this major climate phenomenon are vital to save lives and livelihoods.”

El Niño occurs on average every two to seven years, and episodes typically last nine to 12 months. 

It is a naturally occurring climate pattern associated with warming of the ocean surface temperatures in the central and eastern tropical Pacific Ocean. However, it now takes place in the context of a climate changed by human activities.

El Niño events are typically associated with increased rainfall in parts of southern South America, the southern United States, the Horn of Africa and central Asia.

In contrast, El Niño can also cause severe droughts over Australia, Indonesia, parts of southern Asia, Central America and northern South America.

During the Boreal summer, El Niño’s warm water can fuel hurricanes in the central/eastern Pacific Ocean, while it could hinder hurricane formation in the Atlantic Basin.

Generally, El Niño has the opposite effect of the recent La Niña, which ended earlier in 2023.

El Niño and La Niña are major - but not the only - drivers of the Earth’s climate system.

In addition to the long-established ENSO Update, WMO now also issues regular Global Seasonal Climate Updates (GSCU), which incorporate influences of the other major climate drivers such as the North Atlantic Oscillation, the Arctic Oscillation and the Indian Ocean Dipole.

“As warmer-than-average sea surface temperatures are generally predicted over oceanic regions, they contribute to widespread prediction of above-normal temperatures over land areas. Without exception, positive temperature anomalies are expected over all land areas in the Northern and Southern Hemisphere,” says the latest update for July, August and September 2023.