Your guide to El Niño

El Niño years can be associated with lots of rain in Southern California, though there's no guarantee of a deluge.

And wet winters aren’t always disastrous. What matters is how much water falls within how much time. In fact, going back to when modern records began in 1950, most of the years when we've seen the highest flood-related costs were not during El Niño events.

But there are concerns beyond rain for late 2026 and early 2027.

El Niño this time will coincide with another natural phenomenon — the highest tides of the year in a nearly two-decade cycle known as “the declination of the moon.” We’re reaching the max this winter, according to Scripps scientist Mark Merrifield.

Because El Niño warms the ocean, it also raises sea levels temporarily. On top of that there’s an unprecedented level of human-caused global warming in the mix — that has already raised sea levels by as much as a foot along California’s coast over the last century, and is making normal weather patterns more extreme.

“So  we start adding these things up, and they're actually not so small anymore,” said climate scientist Daniel Swain. “The risk of coastal flooding is actually very high and almost guaranteed.”

It’s not only the coast — inland areas, especially along creeks and rivers, are also at risk due to more extreme rainfall driven by El Niño as well as human-caused global heating, Swain and other experts said.