El Nino is a periodic warming of sea surface temperatures in the central and eastern Pacific Ocean, which typically lasts between nine and 12 months, according to the World Meteorological Organization.

The WMO said warm ocean waters were driving El Nino’s development and predicted above-average temperatures in most parts of the world from June to August. The WMO said it is likely El Nino will continue until November.

It also said it remained uncertain how strong El Nino will be as models ?differ on its severity, but officials warned of the need to be ready.

“We need to prepare for a potentially strong El Nino event - which will exacerbate drought and heavy rainfall and increase the risk of heatwaves both on land and in the ocean," said WMO Secretary-General Celeste Saulo.

MORE DROUGHTS, HURRICANES AND HEAT?
The weather pattern is known to disrupt regional climates, potentially bringing warmer temperatures across the globe, while increasing rainfall to the southern parts of South America and the United States, parts of the Horn of Africa and central Asia.

El Nino can also cause drought in Australia, Central America, Indonesia, and parts of south Asia, and spur hurricane formation in the central and eastern Pacific, the WMO said.
The last El Nino, which meteorologists said was strong, in 2023 to 2024 contributed to making 2024 the hottest year on record, Saulo said.
Saulo said other risks ?associated with extreme heat included a wider spread of diseases borne by vectors such as mosquitoes and ticks and reduced food and water supplies.
“Communities that were already struggling will be pushed farther beyond their limits,” she said.
For consumers, facing inflation because of the Iran war, food prices may rise further because of El Nino.
Hein Schumacher, CEO of Barry Callebaut, one of the world's biggest cocoa processors, warned crops in the growing regions of Ecuador and West Africa that account for ?60% of global output could be reduced.
"This is something that we are very cautiously observing," he told media on a call on Tuesday. "El Nino could have an effect that could lead to, you know, a few thousands per ton."
London cocoa futures are trading at £2,944 ($3,964.10) per metric ton, down from more than 9,000 in ?April 2024.
Some national weather agencies have forecast the strongest El Nino in a decade.
The WMO is more circumspect but said it had observed unusually warm subsurface conditions across the tropical Pacific with temperatures exceeding 6 degrees Celsius (10.8 degrees Fahrenheit) above average, creating a reservoir of heat that is ?driving surface warming.
U.N. Secretary-General António Guterres said it was a reminder of the need for a shift away from fossil fuels towards renewable energy.
“The world must treat it as the urgent climate warning it is. El Nino conditions will pour fuel on the fire of a warming world,” he said.

Reporting by Olivia Le Poidevin; Additional reporting by Paolo Laudani in Gdansk Editing by Nia Williams and Barbara Lewis
Our Standards: The Thomson Reuters Trust Principles.