La Niña Has Officially Returned: What It Might Mean for Winter Weather

It’s official: La Niña is back.

In a monthly update, the National Weather Service’s Climate Prediction Center confirmed today, October 9, 2025, that during September, La Niña conditions emerged.

The climate pattern, one part of a three-category cycle, is associated with the cooling of ocean surface temperatures in the central and east-central equatorial Pacific Ocean. Skiers know La Niña because, historically, it’s shifted temperature and snowfall patterns across North America.

During a La Niña winter, states like Washington, Idaho, and Oregon tend to see more snow than usual. The opposite is true in the American Southwest, including southern California.

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But this La Niña may not last long.

According to the Climate Prediction Center, it’s likely that ENSO-neutral conditions—when neither La Niña nor its counterpart El Niño are in effect— will arrive between January and March.

During a strong La Niña, the effects on winter weather are more consistent.

What Is ENSO?

The El Niño–Southern Oscillation is a three-part climate cycle closely watched by forecasters. Its two phases, La Niña and El Niño, can change how the weather behaves during any given winter. The middle phase, ENSO-neutral, means the climatological dice aren’t loaded in either direction.

La Niña, as already noted, can be a boon for Pacific Northwest skiers, delivering above-average snowfall to ski areas like Mt. Baker, Mt. Bachelor, and Stevens Pass.

El Niño, which occurs when water temperatures in the central and eastern tropical Pacific Ocean warm, flips the script, with snowfall trending above average across the American Southwest.

These patterns occur against a climate change-fuelled backdrop. Regardless of the ENSO phase, winter snowfall is declining across much of North America because of warmer temperatures.

However, there is a silver lining, according to a 2024 blog post on climate.gov. In northern areas where temperatures are staying colder, like Alaska, a moisture-dense, warmer atmosphere can actually create more snow.