El Nino has arrived and is expected to rapidly develop into a strong event between July and September, increasing the likelihood of extreme weather across many parts of the world, the United Nations’ climate agency warned on Friday.
The World Meteorological Organization (WMO) said the climate phenomenon was forecast to strengthen quickly over the coming months and urged countries to prepare for its impacts.
El Nino is characterised by the warming of surface waters in the central and eastern equatorial Pacific Ocean, triggering widespread changes in wind, atmospheric pressure and rainfall patterns around the globe.
The phenomenon typically occurs every two to seven years and lasts between nine and 12 months. Climate conditions generally alternate between El Nino and its cooler counterpart, La Nina, with neutral conditions occurring in between.
According to the WMO’s latest Global Seasonal Climate Update, forecasts indicate “a rapid development into a strong El Nino event during July-September.”
The UN agency classifies El Nino events as weak, moderate, strong or very strong, meaning the current event is expected to reach the third-highest category.
“El Nino conditions have developed in the tropical Pacific and are forecast to strengthen rapidly over the coming months, increasing the likelihood of extreme weather events in many parts of the world,” the WMO said.
WMO climate scientist Alvaro Silva said confidence had increased significantly since last month that strong El Nino conditions were developing in the equatorial Pacific.
“We have much more confidence that strong El Nino conditions are developing in the equatorial Pacific,” Silva told a press conference.
He added that the WMO could issue another update in the coming months if forecasts indicate that the event is likely to become exceptionally strong.
The Geneva-based agency said forecasts from global climate centres consistently showed significant warming across the central and eastern equatorial Pacific, with seasonal average sea-surface temperature anomalies expected to exceed 2 degrees Celsius in key monitoring regions.
“El Nino is expected to continue strengthening during the Northern Hemisphere autumn, with its influence extending across many regions of the globe,” the WMO said.
The previous El Nino contributed to making 2023 the second-hottest year on record, while 2024 became the hottest year ever recorded, with the global average temperature reaching about 1.55 degrees Celsius above the 1850-1900 pre-industrial average.
Although El Nino generally peaks between November and February, its effects on global temperatures often continue well beyond that period.
“The impacts of El Nino will be felt in different regions until the end of the year and beyond, also during 2027,” Silva said.
The WMO said it was expanding early warning support to help governments improve preparedness, particularly in climate-sensitive sectors such as agriculture and public health.
WMO Secretary-General Celeste Saulo said strengthening early warning systems was essential to reducing the human and economic toll of climate-related disasters.
“El Nino conditions are already under way and are forecast to strengthen rapidly into a strong event,” she said.
“This will intensify the chances of drought and heavy rainfall and the risk of heatwaves on land and marine heatwaves in many regions.”
The WMO forecast above-average temperatures across most land areas between 60 degrees south and 60 degrees north from July to September, covering nearly all populated regions outside the polar zones.
Its rainfall outlook also reflects a strengthening El Nino, with above-normal rainfall expected in parts of the southwestern United States, while below-normal rainfall is forecast across the Indian subcontinent and much of Australia.
The agency stressed that there is no evidence climate change increases the frequency or intensity of El Nino events. However, it said global warming amplifies their impacts because warmer oceans and a warmer atmosphere provide more energy and moisture for extreme weather events such as heatwaves and heavy rainfall.
During the Northern Hemisphere summer, warmer Pacific waters associated with El Nino can also fuel hurricanes in the central and eastern Pacific while suppressing hurricane development in the Atlantic.
On Thursday, Peru declared a 60-day state of emergency in 800 of its 1,800 municipalities over the imminent threat of heavy rainfall linked to El Nino.
Authorities warned that more than 9.3 million people face a very high risk of flooding and landslides.
Cox’s Bazar Life Desk/BSS
