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


NOAA has issued a La Niña Watch, which means conditions in the tropical Pacific Ocean are favorable for the development of the cool phase of the climate pattern known as ENSO later this year. However, the probability is not a strong one. There's a 50-55% chance of La Niña, a 40-45% chance of neutral conditions, and still a 5-10% chance of El Niño.

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 June 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

El Niño and La Niña have their strongest influence on global climate during the Northern Hemisphere winter. During La Niña winters, the southern tier of the United States is often drier than normal. Northern Australia, Indonesia, and the Philippines are often wetter than normal. 

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

Map of UV index forecast for July 4, 2020

Ultraviolet (UV) radiation: Don’t feel the burn, avoid it!

July 24, 2020

After so many months cooped up inside trying to flatten the COVID-19 curve, many of us are ready for the great outdoors. This week's guest blogger talks about how to use NOAA's UV forecast products to stay safer in the Sun.  Read more

An example of NOAA's UV index forecast products from July 4, 2020. NOAA Climate.gov image, based on data from the Climate Prediction Center.