La Niña Climate Pattern Has Formally Emerged

After weeks of speculation, La Niña has officially arrived. Here is the latest on the official declaration and what it may mean for the weather patterns heading into the winter season.

Climate Experts Officially Declare La Niña Conditions

La Niña is here. According to a declaration from the National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center (CPC) on Thursday, October 9, La Niña conditions formally emerged in September 2025. Climatologists confirmed the emergence of the climate phase based on the expansion of the below-average sea-surface temperatures throughout the waters of the central and eastern equatorial Pacific Ocean.

The CPC forecasts that La Niña conditions will persist through February 2026. The emergence of this pattern could impact both the fall and winter weather throughout the U.S., as well as the last few weeks of the 2025 hurricane season.

La Niña is a part of a natural climate cycle known officially in meteorological circles as El Niño-Southern Oscillation, or ENSO for short. The two primary climate phases swing between warmer and cooler water temperatures in the zone along the equator in the tropical Pacific. La Niña is distinguished by its cooler-than-average ocean water temperatures in this part of the Pacific basin.