US scientists say El Niño — the natural Pacific climate pattern that pushes global temperatures higher — has officially begun and could intensify into a very strong event, raising the chance of new heat records and wide-ranging weather disruption.
The US National Oceanic and Atmospheric Administration (NOAA) announced that sea surface temperatures across the central and eastern tropical Pacific have risen above the 0.5°C threshold it uses to define El Niño. Atmospheric changes, including shifts in equatorial winds, indicate the ocean warming is now influencing the atmosphere as well.
Many forecast models already point to a powerful event. NOAA’s June outlook gives about a 63% chance that November–January will see a “very strong” El Niño — one that would rank among the largest since records began in 1950. Some US and European models even show central Pacific temperatures rising more than 3°C above average by year’s end. Forecasters caution, however, that model strength estimates are uncertain and that even the strongest El Niños do not produce the same impacts everywhere.
Intensity benchmarks: a “strong” El Niño generally means sea surface temperatures about 1.5°C above average in the key zone; “very strong” is above 2°C. The largest events in the modern record occurred in 1982/83, 1997/98 and 2015/16.
What makes this El Niño particularly worrying is that it is arriving on top of long-term human-caused warming. Experts say a very strong El Niño typically adds around 0.2°C to global air temperatures by releasing ocean heat to the atmosphere. With baseline temperatures already at record highs, that extra boost could produce unprecedented regional heat and push global averages higher — most likely producing another exceptionally warm year in 2027.
Recent context: 2024 was the warmest year on record, aided by an El Niño that was not especially strong; 2025 was still the third warmest year despite a La Niña influence. Scientists warn the coming El Niño could compound existing warming and increase the likelihood of new extremes.
Regional impacts vary. El Niño commonly brings heavy rains and flooding to northern Peru, southern Ecuador, parts of East Africa, Central Asia and the southern United States, while increasing drought and wildfire risk across much of Australia, Indonesia and northern South America. It also tends to suppress Atlantic hurricane activity — which can reduce storms but also diminish vital rains for parts of Central America, worsening drought risk and threats to agriculture.
The human consequences can be severe: failed rains, crop losses, rising food prices and heightened vulnerability for communities already coping with climate shocks. Aid and resilience groups warn that East Africa and other regions battered by recent droughts and floods are particularly exposed.
Not every meteorological agency has declared El Niño in the same terms. Japan’s Meteorological Agency concurs and expects the pattern to persist into autumn. Australia’s Bureau of Meteorology uses a stricter threshold (0.8°C above average) and describes the tropical Pacific as “approaching El Niño conditions,” expecting development later in the year and potential strength.
El Niño events typically recur every two to seven years and usually last about a year. While there is not yet conclusive evidence that climate change is making El Niños more frequent or stronger, a warmer world amplifies their impacts.
Bottom line: NOAA’s declaration signals the start of a period in which weather extremes and higher global temperatures are more likely. The exact severity and regional effects will depend on how strong the event becomes and how climate change continues to shape baseline conditions, but the risks to food systems, water supplies and economies are real and immediate.
