El Niño just broke a historic temperature record — and it’s still intensifying
As of Sept. 20, the Oceanic Niño Index (ONI) stands at +3.04°C, surpassing the warmest value recorded since daily records began in 1982.
FILE: Tracking potential Super El Niño: How could it shape weather patterns across the US?
Experts are suggesting that a super El Niño is likely this year, which could bring major impacts to weather patterns across the U.S. FOX Weather Meteorologists Nick Kosir, Haley Meier, Michael Estime and FOX 26 Meteorologist Allison Gargaro are breaking down what people might see if the super El Niño develops.
THE TAKEAWAY
- El Niño water temperatures surpassed a historic benchmark.
- As of Sept. 20, the Oceanic Niño Index (ONI) stands at +3.04°C, surpassing the warmest value recorded since daily records began in 1982.
- The last warmest value was recorded in November 2015 at +3.02 °C.
El Niño water temperatures surpassed a historic benchmark Sunday as the climate pattern continues to intensify ahead of the upcoming winter.
POWERFUL WAVES BATTER SOUTHERN CALIFORNIA COAST, DAMAGING HOMES AND TRIGGERING SINKHOLE
As of Sept. 20, the Oceanic Niño Index (ONI) stands at +3.04°C, surpassing the warmest value recorded since daily records began in 1982.
(FOX Weather)
According to the FOX Forecast Center, the last warmest value was recorded in November 2015 at +3.02 °C.
El Niño is measured in two primary ways. The first way is through ONI, which measures water temperatures compared to a 30-year average.
However, ONI is the old method for measuring El Niño's intensity and has since been retired by NOAA.
Rocks and cobblestones line Tamarack Beach on Wednesday, Sept. 2, 2026 in Carlsbad, California.
(Meg McLaughlin / The San Diego Union-Tribune / Getty Images)
The newer index, Relative Oceanic Nino Index (RONI), compares water temperatures with the rest of the tropics.
By accounting for a warmer climate, RONI provides a more consistent comparison with past events.
Based on RONI, El Niño temperatures currently sit at +2.50°C, according to the FOX Forecast Center. That remains below the record RONI value of +3.48°C set in December 1982.
(FOX Weather)
The record-breaking ocean temperatures come as El Niño continues to strengthen ahead of the winter season.
According to the FOX Forecast Center, the unusually warm tropical Pacific could contribute to a slight increase in global temperatures and atmospheric moisture in the short term, potentially providing more fuel for intense storms.
However, the broader winter impacts are expected to remain consistent with a typical Super El Niño pattern, which can produce an active weather season across parts of the U.S.
A lifeguard keeps watch along a closed boardwalk as a Pacific Ocean wave crashes over a seawall protecting homes on September 7, 2026 in Long Beach, California. Heavy surf generated by offshore Hurricane Marie, amid a record-breaking ocean heat and an emerging El Niño, caused minor coastal flooding and forced the evacuation of roughly 20 beachfront homes along the Long Beach Peninsula.
(Mario Tama/Getty Images / Getty Images)
The Climate Prediction Center’s winter outlook for December 2026 through February 2027 highlights the typical El Niño pattern, with wetter and stormier conditions favored across the South, particularly the Southeast, while warmer-than-average temperatures are expected across the Northern Tier.
With El Niño still intensifying, FOX Forecast Center will continue monitoring ocean temperatures and atmospheric conditions closely as winter approaches.