A sunset crests over the Scripps Pier in La Jolla.

Hottest. Earliest. Most extreme. California’s meteorologists and oceanographers keep dropping new superlatives about the temperatures in 2026. 

In the first months of the year, a record-smashing heat wave set a new high for the hottest California day in March and prompted a premature spring. Now, experts are turning focus to the heat simmering deep in the Pacific Ocean, which is already likely hurting marine life. 

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“There’s a bunch of claims circulating, some viral social media posts, that this is the most extreme heat wave, oceanic heat wave ever observed in this region, so is that true?” Daniel Swain, a climate scientist for the University of California’s Agriculture and Natural Resources, said during a recent videostream. “Well, by many objective metrics, yes, that is correct.”

The Pacific Ocean is baking for thousands of miles, from about San Francisco all the way to Guatemala, according to recent sea surface temperature data from the National Oceanic and Atmospheric Administration. In this data set, a massive splotch of dark maroon concentrated from California’s Central Coast into Mexico — and also far west offshore — depicts many spots with temperatures ranking in the highest percentiles. 

“The 100th percentile here would mean, for example, the single warmest value ever observed,” Swain explained, “and the 98 percentile means that only 2% of all historical observations were warmer.” 

Smack in the middle of this unprecedented marine heat, scientists from the Scripps Institute of Oceanography at UC San Diego maintain one of the most robust data sets for the sea. They monitor daily temperatures at 10 coastal stations across California, including ones at the Scripps Pier, Newport Beach, Pacific Grove and the Farallon Islands with more than 100 years of data. 

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