El Niño, characterized by warmer-than-normal water temperatures in parts of the equatorial Pacific, made its return in June 2026. Observations of sea surface height from the Sentinel-6 Michael Freilich satellite that month indicated that the 2026 event was continuing to strengthen.
The natural, recurring phenomenon can have widespread effects, typically bringing wetter conditions to the U.S. Southwest and drought to countries in the western Pacific, such as Indonesia and Australia. NOAA declared an El Niño on June 11, after sea surface temperatures in the central and eastern equatorial Pacific measured at least 0.5 degrees Celsius above average for several consecutive months.
Meanwhile, NASA scientists have been observing a complementary sign of El Niño: areas of elevated sea surface height. When ocean water warms, it expands in volume and causes the sea surface to rise—making the water’s height a reliable indicator of ocean temperatures. Warmer-than-normal temperatures, hence higher sea surface heights, in parts of the equatorial Pacific Ocean are associated with El Niño.
The map above depicts sea surface height anomalies across the central and eastern Pacific Ocean as observed on June 8, 2026. Shades of red indicate sea levels that were higher than average. Normal sea level conditions appear white, and lower areas are blue.
Data for the map were acquired by the Sentinel-6 Michael Freilich satellite—launched in 2020 by NASA and led by ESA (European Space Agency)—and processed by scientists at NASA’s Jet Propulsion Laboratory (JPL). Note that signals related to seasonal cycles and long-term trends have been removed to highlight sea level anomalies associated with El Niño and other short-term natural phenomena.
Earlier in spring 2026, the satellite started to detect precursor …