El Niño & La Niña (El Niño-Southern Oscillation)

map of departure from average sea surface temperature in the tropical Pacific Ocean showing cool anomalies near the equator


Forecasters believe the ongoing weak-to-moderate La Niña is currently peaking and will weaken into the spring. The strength of an event isn't strongly linked to the strength of the impacts in the U.S., but strength does increase the likelihood that at least some level of the typical impacts will be felt. The next update will be on February 8.

More ENSO status information
Latest official ENSO update
Latest ENSO blog update
ENSO Monitoring at the Climate Prediction Center


El Niño and La Niña are the warm and cool phases of a recurring climate pattern across the tropical Pacific—the El Niño-Southern Oscillation, or “ENSO” for short.

The pattern can shift back and forth irregularly every two to seven years, and each phase triggers predictable disruptions of temperature, precipitation, and winds.

These changes disrupt the large-scale air movements in the tropics, triggering a cascade of global side effects.

More about El Niño
What is El Niño in a nutshell?
Understanding El Niño (video)
ENSO alert system criteria
ENSO essentials
Educational Resources on ENSO

La Niña, winter impacts

Cooler and wetter in the Northwest, warmer and drier across the South

La Niña is anchored in the tropical Pacific, but through the jet streams, it affects seasonal climate "downstream" in the United States. This map shows typical impacts of La Niña on U.S. winter weather based on past La Niñas, but the exact location and strength of impacts vary from event to event, and some might not occur at all. 

Typical U.S La Niña impacts
Winter temperature and precipitation
Hurricane season impacts
Current outlooks
6-10 day outlook
8-14 day outlook
1-month outlook
3-month outlook

La Niña winters

El Niño and La Niña have their strongest impact on global climate during the Northern Hemisphere winter.  The map at left shows typical December-February rainfall and temperature patterns during La Niña winters, but we may not see all impacts during every event. 

More information
ENSO's cascade of global impacts
The Walker Circulation
More maps of global impacts of La Niña and El Niño

subsurface temperature anomaly, Pacific Ocean, ENSO, La Nina

January 2018 La Niña update: summiting the peak

January 11, 2017

La Nina conditions appear to have peaked in strength and will likely last through the upcoming winter. What does that mean for U.S. impacts?

Read more


(image at left) Sub-surface temperatures in the tropical Pacific in December 2017 compared to the 1981-2010 average. Near-surface waters in the eastern basin are cooler than average, but to the west, a deep pool of warmer-than-average waters suggests La Niña is decaying.