Southern California residents along the coast are bracing for a potentially impactful winter, as a rare alignment of a powerful El Niño, super king tides, and persistent sea level rise threatens to bring record coastal flooding. Officials are already observing higher tides than usual, with swells eroding beaches and damaging parking lots and restrooms. In Newport Beach, the powerful waves at The Wedge have even resurfaced what’s believed to be part of an old jetty.
Jonathan Warrick, a research geologist with the U.S. Geological Survey, explains that El Niño, often seen as a rainmaker for our region, also significantly affects ocean levels. “There’s a phenomena during El Niños where the waters offshore California get warmer, and they actually rise up, up to a foot, sometimes more, higher than average,” Warrick said. This warming and expansion of ocean water offshore is already evident, with water levels along the South American Pacific coast observed to be half a foot to a foot above average, according to UC climate scientist Daniel Swain.
The National Oceanic and Atmospheric Administration’s marine heat wave tracker notes that while some recent heating off Southern California might be from El Niño, parts of the coast have been experiencing a marine heat wave for months that is unrelated to the pattern. Nevertheless, the combination of factors means this winter could bring the highest sea levels ever recorded to the California coast, raising the risk of widespread damage.
Historical data shows this pattern isn't new; the “very strong” El Niños of 1982-83 and 1997-98, along with a “strong” one in 2023-24, saw San Francisco Bay log record monthly average sea levels. This year, a “super” El Niño is 95% likely to develop.
Compounding the issue, California’s annual king tides will be exceptionally high. Mark Merrifield, director of Scripps’ Center for Climate Change Impacts and Adaptation, notes that “around Christmastime, California will see some very strong king tides that will superpose on the high sea levels caused by El Niño.” This is due to longer lunar tidal cycles nearing their peaks this year. These highest tides are expected on Thanksgiving Day, Christmas Eve, and January 22nd.
Jeremy Smith, a coastal engineer with the California Coastal Commission, reports that recent tides were already coming in four to nine inches higher than predicted in places like San Diego, Santa Monica, and Humboldt County. If these exceptionally high tides coincide with winter storms, significant coastal erosion, flooding, and damage are likely. Low-lying areas such as Mission Beach, Newport Beach, Sunset Beach, and parts of Long Beach like the Peninsula and Belmont Shore are particularly vulnerable.
Beyond the direct impact on sea levels, El Niño also increases the likelihood of above-average precipitation across Southern California, with the Climate Prediction Center expecting a wet January through March. The 1982-83 winter, a strong El Niño year, was California’s wettest in 131 years, illustrating the dual threat of rising waters and heavy rain.
