The National Oceanic and Atmospheric Administration (NOAA) said El Niño has formed in the tropical Pacific. El Niño is a phenomenon in which rising sea temperatures near the equator in the Pacific trigger extreme weather around the world. When El Niño intensifies, the United States and China see floods, while Southeast Asia, Australia and Africa face drought. Scientists warned that with fertilizer supplies already reduced this year because of the Iran war, the overlap with El Niño could sharply cut agricultural output in less developed countries.
The National Weather Service under NOAA said on the 11th (local time) that it issued an El Niño watch because "there is a 63% chance that sea surface temperatures in the monitored areas of the Pacific will exceed 2 degrees Celsius." The Korea Meteorological Administration predicted that El Niño will become moderate or strong in the coming fall.
El Niño is the precursor stage of the El Niño–Southern Oscillation (ENSO). ENSO refers to a global climate pattern in which sea surface temperatures and atmospheric pressure in the eastern Pacific vary periodically. It is divided into El Niño, when sea surface temperatures are higher than average, and La Niña, when they are lower. Both terms come from Spanish meaning "boy" and "girl," and both have major impacts on Earth's climate.
◇ Crisis detected since April, likely to bring floods and drought
El Niño is defined by a three-month average sea surface temperature in the tropical Pacific monitoring region that is at least 0.5 degrees above normal for more than five months. Observations show that from late April to mid-May, sea surface temperatures in the central and eastern equatorial Pacific neared the El Niño threshold. Meteorologists used this to anticipate the return of El Niño months in advance.
The World Meteorological Organization (WMO) said on Apr. 24 that sea surface temperatures are surging and El Niño is expected around May to July. On the 2nd, it offered a more specific outlook, saying there is an 80% chance of El Niño developing between June and August. The WMO predicted a better than 90% chance that El Niño will persist at least through November.
NOAA's announcement nearly doubles the probability of sea temperature rise it projected in May. NOAA forecast that through November, tropical Pacific sea temperatures will rise by 2.4 degrees, releasing heat and moisture into the atmosphere and disrupting weather patterns worldwide.
El Niño typically strengthens most in the Northern Hemisphere winter and drives global temperature increases into the following year. In fact, the El Niño events of 2023 and 2024 coincided with the two hottest years on record. Scientists warned that 2027 is likely to set a new heat record.
Experts worried that this year's El Niño could exceed a 3-degree Celsius sea surface temperature rise and become the largest on record. Malte Stuecker, a University of Hawaii professor and director of the International Pacific Research Center, said, "This year's El Niño is hard to find a precedent for," adding, "In the context of ongoing global warming, this would be quite catastrophic."
◇ Food crisis fears as war worsens fertilizer shortages
The weather disruptions caused by El Niño vary by region. The southern United States, East Africa and parts of China could see floods, while Indonesia, Australia and southern Africa could face higher risks of drought and wildfires. This year, war has made matters worse. The closure of the Strait of Hormuz due to the Iran war has sharply reduced fertilizer supplies, potentially bringing a food crisis to less developed countries. To make matters worse, humanitarian aid from advanced economies has also been cut back in succession.
Mohamed Adow, director of the Nairobi-based climate and energy think tank Power Shift, told the New York Times that day that El Niño means "no rain, crops withering, food prices rising, and households once again being pushed to the brink," and warned, "In East Africa in particular, this will hit communities that have already suffered heavy blows from droughts and floods in recent years."
Domestic experts warned that El Niño could bring extreme weather such as torrential downpours to Korea. They further raised concerns that disruptions to food supply could trigger an economic crisis.
Cho Chun-ho, former head of the National Institute of Meteorological Research, said, "There is a lag of several months before El Niño that develops in the equatorial Pacific affects Korea through atmospheric circulation," adding, "Rather than immediate changes from El Niño, we should proactively prepare for extreme weather this winter and next summer."
Cho predicted that this winter, temperatures will be higher than average nationwide, with moist air flowing in from the south, leading to a sharp increase in precipitation (snow and rain). Next summer, as the North Pacific high retreats southwestward and the stationary front becomes more active, temperatures are likely to fall in the southern regions and torrential rains are likely.
Oh Jae-ho, CEO of NanoWeather (emeritus professor at Pukyong National University), said, "This year's El Niño should be recognized not as a simple climate event but as a risk factor that could threaten national food security and economic security." Korea's food self-sufficiency rate is only about 25%, meaning that abnormal weather in major grain-producing countries for wheat, corn and soybeans can immediately translate into rising food prices and import instability. Oh proposed, "To diversify supply chains, Korea needs to establish a national early warning system that monitors and forecasts in real time the weather and climate conditions, crop conditions and yield outlooks in major grain-producing countries."
References
NOAA (2026), https://www.noaa.gov/news-release/el-nino-forms-expected-to-strengthen-say-noaa-forecasters
WMO (2026), https://wmo.int/resources/publication-series/el-ninola-nina-updates/el-ninola-nina-update-may-2026