WASHINGTON, Oct 10 — The climate phenomenon known as La Niña has returned, a US agency announced yesterday. It is expected to remain weak, limiting its ability to cool the planet and supercharge Atlantic hurricane activity.
La Niña is a naturally occurring climate pattern that cools surface temperatures in the central and eastern equatorial Pacific Ocean.
Because of changes in vertical wind shear — the variation in wind speed and direction high in the atmosphere — this phenomenon tends to bring more hurricanes in the Atlantic basin and fewer in the Pacific.
Conditions oscillate between La Niña and its opposite, El Nino, with neutral phases in between.
Following a brief spell of weak La Niña conditions between December 2024 to March this year, neutral conditions had persisted. But the US National Weather Service declared Thursday the phenomenon was back.
“La Niña conditions emerged in September 2025, as indicated by the expansion of below-average sea surface temperatures (SSTs) across the central and eastern equatorial Pacific Ocean,” the agency said.
This climate pattern is expected to persist through the winter, with a 55 percent chance of transitioning back to neutral conditions between January and March 2026.
The NWS added that this La Niña’s predicted weakness “would be less likely to result in conventional winter impacts.”
The unusually long-lasting 2020–2023 La Niña was the first so-called “triple-dip” event of the 21st century — and only the third since 1950. It intensified both drought and flooding in different parts of the world.
However, despite La Niña’s typical cooling influence, it did nothing to halt the streak of exceptionally hot years. The past decade comprises the 10 hottest individual years ever recorded.
Temperatures have remained at record or near-record levels even after El Nino conditions faded last year — with 2024 the hottest year on record.
The Atlantic hurricane season runs from June 1 to Nov. 30. The National Oceanic and Atmospheric Administration continues to forecast an above-normal season. But so far it has been slightly below average and no storms have yet made US landfal. — AFP
