Record high ocean temperatures off southern California raise fears of prolonged marine heatwave

The waters of southern California historically warm every few years. But the marine heatwave that started last fall wasn’t caused by tropical currents. Photograph: Kevin Carter/Getty Images

For more than a century, shoreline stations operated by the Scripps Institution of Oceanography have measured water temperatures along the California coast. This year, they are flashing a warning sign.

Over the last three months, several stations have repeatedly posted record-breaking daily high temperatures – with the La Jolla station registering temperatures a full 10F above historical average at one point last month.