El Niño & La Niña (El Niño-Southern Oscillation)
The chances of La Niña this fall were 75% in June, but they fell to around 55-60% in July, and again in August to 40%. Sea surface temperatures were cooling, but the pace of cooling has slowed. ENSO conditions are likely to remain neutral through fall. Forecasters have dropped the La Niña watch. The next update will be October 13.
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.
No ENSO impacts
NOAA declared El Niño oficially over at the end of May 2016. As of August, the ENSO alert system was not active, meaning neither La Niña nor El Niño was expected to develop within 6 months, leaving other factors to determine U.S. fall and winter climate. NOAA will issue the next seasonal outlook on September 15. The map at left shows the temperature outlook for September. Precipitation outlooks are available in our Data Snapshots map colection.
El Niño and La Niña have their strongest impact on global climate during the Northern Hemisphere winter & early spring. However, parts of the tropics and Southern Hemisphere sub-tropics feel the effects of ENSO during Northern Hemisphere summer months.
The map at left shows typical circulation, rainfall, and temperature patterns in the tropics during El Niño and La Niña in the Northern Hemisphere winter. NOAA Climate.gov map.
Featured Resources & Articles
Images & Maps
ENSO across NOAA
Societal & ecosystem impacts
Regional & Local Impacts
ENSO @ the Ocean Institute of Peru (Spanish)
ENSO @ the Centro Internacional para la Investigación del Fenómeno de El Niño (CIIFEN) (western South America, Spanish)
Events & Announcements
NOAA National Weather Service Daily Briefing
Briefing page with forecasts, discussions, maps, assessments, and severe weather outlooks for today’s developing weather patterns across the United States.
El Nino: What's Next?
February 18, 11 am CT
Hosted by SCIPP
NOAA Monthly Climate Briefing for Media
Thursday, February 18, at 11 am EST
Teleconference for public media on past month’s weather & climate conditions for the U.S. & globe, an update on El Niño, and NOAA’s 3-month climate outlook.
California Winter Status Update
January 26, 4 - 6 pm EST