Record Tides Flood California Coast From San Diego to Marin
Seawater inundated low-lying communities this week. Scientists warn that El Niño and warm ocean water could push tides higher later in the winter.
Record-breaking high tides flooded the California coast this week, from San Diego to the San Francisco Bay Area. Seawater submerged streets, homes and businesses and jammed transport corridors and train routes.
In Marin county, north of San Francisco, kayakers and paddleboarders glided along normally busy roads on Monday and Tuesday. Several drivers had to be rescued from floating cars. Cyclists who tried to cross the temporary lagoon quickly found themselves waist-deep. In Newport Beach, water pounded emergency barriers and seeped through berms, seawalls and sandbags.
Near Los Angeles and San Diego, tides rose above 8ft. San Francisco recorded its highest October reading on Wednesday, beating the record set the day before.
Warnings and a rough autumn
The National Weather Service issued flood advisories and warnings lasting for days. For San Diego and Orange counties, forecasters expected significant coastal flooding during high tides through Thursday. "Numerous roads may be closed," they said. Moderate flood risks in Los Angeles extend into the weekend, though tides begin to drop after Thursday. Shoreline erosion is expected along the coast.
Southern California has been hit several times over the last two months. According to NOAA records, Los Angeles has logged 12 coastal flood days in 2026, more than in any year in the last 50, with months still to go.
What scientists expect
Experts warn the worst may be ahead as an exceptionally strong, still-strengthening El Niño unfolds, with potential to lift tides several feet above this week's levels. Climate scientist Daniel Swain said on Tuesday: "What we are seeing now could be the beginning of what could be significantly more disruptive conditions later this year."
He explained that the high water comes from thermal expansion due to a record oceanic heatwave, layered on sea levels raised by human-caused climate change. A coastally trapped Kelvin wave, a band of warm water moving up the North American shoreline, adds to it. "I would expect these water levels to be exceeded multiple times this winter," Swain said.
A NOAA outlook gives San Diego, La Jolla, Los Angeles and Santa Monica above an 80% chance of high tide flooding in December. Most stations farther north to the Canadian border fall in the 60% to 80% range.
This week's floods were not king tides, the highest predicted of the year. Those are due around Thanksgiving and Christmas, and on 20 to 23 January. Aligned with other factors, they could produce up to 5ft of sea level rise above average in many places at once. Swain put the odds of stacking all of these this winter at "at least 30-40%".
Source: The Guardian