SINGAPORE, April 24 (Reuters) – Global weather forecasters predict a strong El Nino weather phenomenon will build during the second half of 2026, threatening hotter and drier weather across much of Asia, while boosting rains in parts of North and South America.
WHAT FORECASTERS PREDICT:
Japan’s weather bureau says there is a 70% chance for an El Nino to emerge during the northern hemisphere summer, while Indian weather authorities warn the South Asian nation’s monsoon season could be below average for the first time in three years.
Weather officials in China expect El Nino conditions to run through the end of the year after emerging in May.
U.S. Climate Prediction Center sees a 61% chance of an El Nino during the period from May to July.
The Australian Bureau of Meteorology is predicting below long-term median rains in eastern cropping regions between May and August, the first half of the country’s growing season.
Weather models indicate rains below, and temperatures above, normal across Australia, Southeast Asia and India, said Chris Hyde, a meteorologist at weather intelligence firm Meteomatics with its headquarters in Switzerland.
“Overall, I think it’s going to be ideal growing conditions across the U.S. Midwest this year,” he added. “We will have to watch the timing of El Nino, there could be some impacts to excessive moisture towards harvest.”
WHAT ARE THE EL NINO, LA NINA WEATHER EVENTS?
They are opposite phases of the same climate system in the tropical Pacific.
El Nino is a natural pattern of unusually warm sea surface temperatures in the central and eastern equatorial Pacific.
It builds when shifts in atmospheric pressure weaken, or even reverse, normally steady easterly trade winds, allowing eastward movement of warm waters piled up in the western Pacific, for a redistribution of heat, altering global weather patterns.
A La Nina forms when trade winds strengthen, pushing more warm water toward the western Pacific and allowing colder water to upwell in the east, driving sea surface temperatures below normal.
La Nina often brings above‑average rainfall to Australia and parts of Southeast Asia, but its impact on the Indian monsoon is variable, rather than uniformly strengthening.
In the Americas, La Nina tends to lead to wetter conditions in parts of northern South America and drier conditions in the southern United States. Overall, the Americas broadly turn drier.
An El Nino occurs every three to five years on average and a La Nina once every three to seven years, says Australia’s Bureau of Meteorology.
WHAT WAS THE IMPACT OF PREVIOUS EL NINO EVENTS?
El Nino events vary in severity and impact.
A strong one in 2015 and 2016 caused severe drought across Australia and Southeast Asia, while weakening the Indian monsoon. It reduced output of grain, palm oil and sugar.
At the same time, excessive rain in parts of South America disrupted soybean and corn harvests.
A moderate El Nino in 2009 and 2010 brought dry weather that reduced yields of staples rice and wheat in India and Southeast Asia.
The strongest El Nino on record was in 1997–1998. It caused drought in some parts of Asia slashed rice production, although India received average rainfall. Flooding in the Americas damaged crops.
The most recent instance of a strong La Nina was from 2020 to 2023.
(Reporting by Naveen Thukral; Editing by Clarence Fernandez)
