El Niño/La Niña Watch & PDO

El Niño 2026

The 2026 El Niño grew rapidly through the summer and is on track to be as large or larger than the historic 1997-98 event. The animation below shows the development of the 2026 El Niño from March 2 to the latest. Like the historical images, these data are processed to remove the natural yearly cycle, and also the long-term trend caused by human interference with the climate. In April and again in May, Kelvin waves, which show as bursts of high sea level (red and white colors) moving from west to east along the Equator. In July, the high sea levels (up to 30 cm or 1 foot above normal) reached Peru and by July and August Kelvin waves were spreading the high sea level signal north toward Baja and Mexico. The high seas and warm waters in the Eastern Pacific have contributed to the unusually active hurricane season there.

Press Release(s):

• How 2 US, European Satellites Are Studying Hurricanes During El Niño (Sept 9, 2026)

---

Update: September 2026

The 2026 El Niño continued to grow through September, even as the highest sea levels reached South America. Kelvin waves have begun to carry the high sea levels up and down the west coast of the Americas. At this point, the 2026 event is as large or larger than the 1997-98 event. Sea levels that are 15 to 20 cm (6 to 8 inches) lower than normal are also seen around Indonesia and northern Australia.

While the images show the current event somewhat stronger than the 1997-98 El Niño, it is important to remember that the long term trend has been removed to compute these images. This means that the effects of long-term warming have been removed. The SSH-based El Niño index (calculated as described in the work of Hamlington et al., 2019) has not had this effect removed, and shows the current event similar in strength to the 1997-98 event at this point in mid-September. Regardless of which event is “larger”, the impacts of the current El Niño will be felt worldwide as it continues to strengthen until the New Year.

Using a sea level-based indicator for El Niño, calculated as described in the work of Hamlington et al., 2019, it is clear that the 1997 and 2015 events were much larger at the same time of year. The graph shows the indicator as it changes throughout the year for all three El Niños: 1997, 2015 and 2023. The higher the value, the stronger the El Niño event. While these events usually peak in November, their impacts are often felt well into the new year. This year’s event will undoubtedly continue to affect weather patterns for several months to come.

The slider below allows for a direct comparison between the 1997 and 2026 El Niños during September. This slider will be updated monthly as the 2026 event continues to evolve.

2026 and 2015 El Niños