Scientists Update El Nino Labeling as Climate Change Alters Weather Patterns

New study links recent temperature spike to shift from La Nina to El Nino cycle

Published on Mar. 2, 2026

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Meteorologists say the natural El Nino weather cycle is both adding to and being shaped by a warming world. A new study found that an unusually long La Nina period from 2020-2023 contributed to a noticeable spike in global temperatures over the past three years. Separately, scientists have had to update how they label El Nino and La Nina events due to rapid changes caused by climate change, with the U.S. National Oceanic and Atmospheric Administration altering its calculations to account for increasingly hot global waters.

Why it matters

The El Nino-La Nina cycle has major impacts on weather patterns worldwide, affecting precipitation, temperatures, and events like hurricanes. As the climate continues to warm, understanding these cycles and how they are evolving is crucial for preparing communities for extreme weather. The changes in labeling also highlight the challenges of defining 'normal' in a rapidly changing climate.

The details

The new study in Nature Geoscience found that about three-quarters of the recent increase in Earth's energy imbalance, which leads to warmer temperatures, can be attributed to the combination of long-term human-caused climate change and the shift from a three-year cooling La Nina cycle to a warming El Nino. La Ninas typically correspond to a one- or two-year buildup of extra energy, but the unusually long 2020-2023 La Nina allowed more heat to be trapped on Earth. When the cycle shifts to an El Nino, that trapped heat is released, causing a spike in global temperatures.

  • From 2020 to 2023, Earth experienced an unusual 'triple dip' La Nina without an El Nino in between.
  • NOAA's forecast is for an El Nino to develop later in 2026, likely leading to a new global temperature record in 2027.

The players

Yu Kosaka

A climate scientist at the University of Tokyo and co-author of the new study.

Tom Di Liberto

A former NOAA meteorologist who is now with Climate Central.

Jennifer Francis

A scientist at the Woodwell Climate Research Center.

Nat Johnson

A meteorologist at NOAA's Geophysical Fluid Dynamics Lab.

NOAA

The U.S. National Oceanic and Atmospheric Administration, which has updated how it calculates and labels El Nino and La Nina events.

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What they’re saying

“If our body's temperature is high then it tends to emit its energy out, and the Earth has the same situation happening. And as the temperatures increase, it acts to emit more energy outward. And for three-year La Nina, it's opposite.”

— Yu Kosaka, Climate scientist, University of Tokyo (Nature Geoscience)

“When there is a transition from La Nina to El Nino, it's like the lid is popped off, releasing the heat.”

— Tom Di Liberto, Former NOAA meteorologist, Climate Central (AP News)

“When El Nino develops, we're likely to set a new global temperature record. 'Normal' was left in the dust decades ago. And with this much heat in the system, everyone should buckle up for the extreme weather it will fuel.”

— Jennifer Francis (AP News)

What’s next

NOAA's forecast is for an El Nino to develop later in 2026, which could dampen Atlantic hurricane activity but also lead to warmer global temperatures in 2027.

The takeaway

As the climate continues to warm, understanding the evolving El Nino-La Nina cycle and updating how these weather patterns are defined is crucial for preparing communities for the increasing extreme weather events they will fuel. The recent temperature spike linked to the shift from a prolonged La Nina to an El Nino underscores the need for continued climate adaptation efforts.