NASA satellites show Pacific sea levels up to 1.3 feet above normal as El Niño builds

Ocean surface in parts of the Pacific now sits 1 to 1.3 feet (30 to 40 centimeters) higher than normal, and NASA satellites are tracking the bulge as El Niño builds while NOAA puts the odds at 83 percent that the strongest event since 1950 is unfolding. NASA published the findings on October 15, 2026, describing a 2026 El Niño that farmers, firefighters and coastal communities are already feeling.

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The raised water reaches from the central Pacific toward South America and up the coast to California, while the opposite signal appears on the far side of the ocean, where sea levels have dropped.

Sentinel-6 and the rise in sea surface height

The measurements come from the Sentinel-6 satellites, which survey ocean height across the whole ocean about every 10 days, to fractions of an inch, according to NASA’s report on the 2026 El Niño. Mission details on the Jet Propulsion Laboratory’s Sentinel-6 page describe the spacecraft as a radar altimeter orbiter launched on November 21, 2020, from Vandenberg Air Force Base in California, part of a pair meant to extend a decades-long sea level record to about 2030. NASA is developing the mission with the European Space Agency, EUMETSAT and NOAA, and its instruments include a Poseidon-4 radar altimeter and an Advanced Microwave Radiometer for Climate.

Water in some areas stands 1 to 1.3 feet above normal, moving toward South America and up to California. Around Indonesia and northern Australia the sea surface is about 6 to 8 inches (15 to 20 centimeters) below normal. Satellite altimetry has tracked ocean height since 1993, so the current readings can be set against more than three decades of records, and the Sentinel-6 radar altimeters survey millions of square miles of ocean in a single day alongside NOAA’s ocean sensors and buoys.

Kelvin waves and warm surface water

NASA traces the build-up to a Kelvin wave spotted near Micronesia in the western Pacific in January 2026. By early April, Kelvin waves had reached the eastern Pacific, and surface temperatures there began to climb. Josh Willis, project scientist for sea level missions at NASA’s Jet Propulsion Laboratory, called Kelvin waves “the heartbeat of El Niño,” and said the pattern affects almost everyone in some way each time it occurs.

Eastern Pacific surface waters are now about 3 degrees Fahrenheit (1.7 degrees Celsius) above the long-term average, and Willis said temperatures could rise another fraction of a degree in the coming months. A band of warmer water stretches for millions of square miles, from the central Pacific to the coast of South America. Microwave and infrared radiometers measure that surface heat through clouds, and the warm water influences rainfall and weather patterns worldwide.

NOAA’s odds and the ocean color signal from PACE

The forecast context comes from NOAA. As NASA notes, the agency put the chance at 83 percent as of October that the strongest El Niño since 1950 is unfolding, a figure drawn from the Climate Prediction Center’s ENSO discussion. That discussion, dated October 8, keeps an El Niño Advisory in effect and says the event will continue to strengthen through the end of the year. It reports a Niño-3.4 index of +2.1 degrees Celsius and gives the chance of a historic event, defined as a three-month index of +2.5 degrees or more, as 54 percent for September to November, 83 percent for October to December and 70 percent for November to January.

A second NASA spacecraft is seeing the biological side of the event. The PACE satellite, launched in 2024, is the first to observe an El Niño since its launch, and its Ocean Color Instrument measures hyperspectral color across several hundred wavelengths from ultraviolet to near-infrared. Equatorial Pacific waters have grown measurably bluer in recent months, while the green area in the western Pacific is shrinking, which indicates fewer phytoplankton.

Weaker trade winds are the cause, according to the NASA report. They reduce upwelling of nutrient-rich deep water, and with less food available, phytoplankton decline, which can disrupt the marine food web and push marine life toward new feeding grounds. Matthew Kehrli, lead research scientist on the PACE team at NASA’s Goddard Space Flight Center, said that “it’s amazing the multitude of colors the ocean can be.”

Visualizations and further reading

NASA has posted data visualizations and downloads of the observations on its Scientific Visualization Studio page, and the agency’s Earth Observatory has run a companion item, “El Niño Is Underway,” on the early signs. El Niño is a natural climate pattern that emerges roughly every two to seven years, marked by warmer-than-normal water in parts of the equatorial Pacific. NASA says the warm water influences rainfall and weather patterns worldwide, which is why the agency’s satellite teams are tracking sea height, temperature and ocean color together as the event develops through the winter.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.