TROPICAL PACIFIC — An El Niño weather pattern has formed in the tropical Pacific. This pattern occurs when trade winds weaken, allowing warm ocean water to move from the Eastern Pacific toward the Americas.

Meteorologist Nat Johnson stated, "If we have a big El Niño on top of the long-term warming trend, that just really enhances the probability that we'll see a new record global mean temperature." The hottest years on record have generally coincided with active El Niño periods. Potential impacts of the pattern include heat waves and abnormally dry conditions in regions such as Europe, India, and Australia.

There is a 63 percent probability of a very strong El Niño occurring from November to January, which would rank among the largest events in historical records dating back to 1950. This pattern could be a major weather event in 2026 and continue into 2027. Global jet streams transfer the influence of the weather pattern to various continents.

A strong El Niño would increase average global temperatures. El Niño typically brings enhanced drought to locations spanning from Indonesia to the northern Amazon. El Niño conditions typically inhibit hurricane formation in the Atlantic Ocean, although climate change has increased temperatures in the Atlantic Ocean.

Predicting the specific effects of a strong El Niño in the U.S. is complex. "What we experience in our own backyard is usually going to be a combination of many different things, including potentially El Niño." Johnson said. During a typical El Niño, impacts tend to be strongest in mid-latitudes and higher latitudes during late fall and winter. The southern U.S. mainland typically experiences wetter weather, while the northern contiguous U.S. typically experiences warmer conditions, and the Pacific Northwest often experiences drier conditions. Climate scientist Daniel Swain explained the function of El Niño, stating, "Its function in the global earth system is to release heat from the deeper oceans that has been temporarily stored there." He added, "El Niño allows that subducted heat to be unearthed."

No independent assessment of El Niño’s claims was available.