NOAA Declares 2026 El Niño Underway, Sees Over 50 Percent Chance It Becomes Very Strong

The National Oceanic and Atmospheric Administration has declared that a 2026 El Niño is officially underway. NOAA also stated that this El Niño has a greater than 50 percent chance of turning into a super El Niño. Kevin Trenberth, a scientist at the University of Auckland and a distinguished scholar at the National Center for Atmospheric Research in Boulder, Colorado, described an El Niño as an exceptional warming of the central and eastern tropical Pacific Ocean.

The Pacific Ocean in the tropics extends more than a quarter of the way around the globe. Easterly trade winds normally pick up warm water and form a deep pool in the Western Pacific, Trenberth said. In 2026, warm water surged across to the Eastern Pacific.

Atmospheric circulation changes usually occur after September during an El Niño year, with the strongest effects in the Pacific typically peaking around December. A mini global warming from El Niño tends to peak around February of the following year, which would be February 2027.

An El Niño is classified as very strong when the index exceeds 2 degrees Celsius above average over an extensive tropical Pacific region.

There have been about three very strong El Niño events on record. El Niño events occur once every two to seven years and typically last about a year. The key tropical Pacific monitoring system consists of moored buoys maintained by NOAA with contributions from other nations.

Trenberth noted that if the NOAA contribution weakens, the information flow also weakens. Global temperature is expected to be the highest on record from approximately June 2026 through June 2027 due to this El Niño. Atmospheric CO2 concentrations are at the highest level ever recorded.