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

Globe-style map of the tropical Pacific Ocean for April 2020 showing warmer than average surface waters in red and orange and cooler than average waters in blue

ENSO: Not Active

In April, the warm anomaly across the surface of the central tropical Pacific was weakened by upwelling of cooler waters from below. The ENSO forecast team estimates a 65% chance that the tropical Pacific will continue in ENSO-neutral this summer.  The probability of a winter La Niña has increased since last month's forecast, but it remains only slightly more likely than neutral. 

More ENSO status information

Latest official ENSO update
Latest ENSO blog update

(image at left) Difference from average sea surface temperatures at the equator in the tropical Pacific in April 2020. 

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

Globes showing typical climate impacts over the U.S. during El Niño and La Niñaca

El Niño is anchored in the tropical Pacific, but it affects seasonal climate "downstream" in the United States. In the summer, El Niño's primary influence on U.S. climate is on the hurricane season in both the eastern Pacific and the Atlantic. 

Typical ENSO impacts
Winter temperature and precipitation
Hurricane season impacts
Current outlooks
6-10 day outlook
8-14 day outlook
1-month outlook
3-month outlook

Animated gif of global maps of winter and summer impacts of El Niño

El Niño has its strongest influence on global climate during the Northern Hemisphere winter, but summer impacts do occur, especially in the tropics. 

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

May 2020 ENSO update: road trip

May 14, 2020

Pack your thermos of coffee and pop a tape in the cassette deck... we're going to tour some roadside attractions, ENSO-style.  Read more

(left) In early April, cooler-than-average water from beneath the surface of the tropical Pacific diminished the warm surface anomaly that had been in place for a few months.