Deep Ocean El Niño Readings Rise

Temperatures Below Ocean Surface Reach Striking 18°F Higher than Normal as U.S. Braces for ‘Super’ El Niño and Blob Descends on Santa Barbara Channel

A map of sea surface temperatures across the equatorial Pacific Ocean clearly displays El Nino conditions (darker reds), but the depths below have heated to more than 18°F above normal. | Credit: Climate Prediction Center

The monthly El Niño discussion released by the Climate Prediction Center held a startling number this August: The temperatures below the ocean surface reached a striking 10°C (18°F) higher than normal, and that’s at about 100 meters (330 feet) below the surface. “It’s an indication that there is a lot of fuel still left in the tank to fuel this El Niño,” said Michelle L’Heureux, who heads up the El Niño team at NOAA’s Climate Prediction Center.

In fact, across the entire eastern Pacific — the equatorial waters that generate an El Niño — the increases in temperature from the surface down to 330 meters (1,082 feet) are the largest in a historical record that goes back to 1980, she said. However, the large temperature changes in the deeps will remain down at the thermocline, where rapid mixing of the upper-ocean warm layer and cooler bottom water can lead to big anomalies.

At the surface, the temperature increases range from 1.4°C near Tahiti to 2.9°C at coastal South America (or 2.5-5.2°F). These are up a couple tenths of a degree (Celsius) from the month before, adding to the certainty that an El Niño is headed our way. That forecast grew over the summer, reaching 81 percent in July and 90 percent in August.

Surface temperatures from 1880-2024 compared to 20th-century average show 2024 as the warmest year on record since global record keeping began in 1850. Global surface temperatures that year on average were 1.29°C (2.32°F) above the average of 13.9°C (57°F). | Credit: Courtesy archived NOAAClimate.gov

As the warmer waters heat the atmosphere above, in the Pacific region, the jet stream drops southward and pulls storms in from the ocean. Globally, 2025 was the third warmest year on record since 1850, according to Berkeley Earth, despite it being a La Niña year, or the opposite of an El Niño and cooler. A mix of reasons account for the temperature variations, both natural and manmade, Robert Rohde wrote at Berkeley, with methane, carbone dioxide, and other greenhouse gase levels steadily growing over the past five decades.

The solid red line reflects the El Niño of 1997-98, when Santa Barbara County’s rain total was 245 percent of normal, while the black line shooting upward reflects equatorial Pacific water temperatures as of July 2026. | Credit: Courtesy Climate Prediction Center

For Santa Barbara, the collection of mid-Pacific readings are retracing the tracks of El Niño in 1997-98, which was a heavy one that saw rain reaching 247 percent of normal and 87 inches at San Marcos Pass and 46 inches downtown.

Separately, the Blob off Southern California has moved into the Santa Barbara Channel. The ocean, which is seasonally warmer as fall approaches, is now several degrees above that normal.