June 17, 2026 — The forecasted El Niño—a mysterious but well-documented climate phenomenon—has officially begun, the National Oceanic and Atmospheric Administration (NOAA) announced on June 11. Meteorologists expect it to evolve into one of the most powerful ones on record, and the event will likely bring about extreme weather worldwide and consequently affect the economy.
“We need to prepare for a potentially strong El Niño event, which will exacerbate drought and heavy rainfall and increase the risk of heatwaves both on land and in the ocean,” says Celeste Saulo, secretary-general of the World Meteorological Organization, in a statement.
Here’s what you need to know about the El Niño and what it might do in the coming months.
What is El Niño?
El Niño is a naturally occurring climate pattern characterized by warmer-than-average surface water temperatures in the Pacific Ocean’s tropical region, near the equator. In the United States, the events are usually declared when the temperature rises by more than 0.9 degrees Fahrenheit for at least five consecutive seasons, each lasting three months.
The balmier water leads to changes in the air pressure. That, in turn, causes trade winds that blow westward to weaken, allowing warmer water to spread farther east than normal and pool near northwestern South America.