The giant surf is being generated by a low-pressure system in the Northern Pacific and is expected to slam beaches from near the Oregon border all the way south to Big Sur. The National Weather Service has warned that some sets could exceed 30 feet, creating dangerous rip currents and the potential for waves to sweep over beaches and infrastructure.

“Entering the water or approaching hazardous coastal areas puts not only your life at risk, but also the lives of the marine safety personnel who may be called upon to rescue you,” Santa Cruz Fire Chief Rob Oatey said in a statement. “Please respect these closures and give the ocean the space it demands.”

The closures extend beyond Santa Cruz. In Monterey County, Asilomar State Beach and the Coastal Trail will also shut down during the same window, and parks officials said the closure could be extended through Tuesday if hazardous conditions persist. Several other beaches from Del Norte County to Sonoma County and down to Monterey were also closed this weekend because of the towering waves and high winds.

The swell is linked to a strong El Niño pattern, which warms the Pacific and is known for producing unusually large waves that can reshape coastlines and cause significant erosion. Scientists have warned that when high tides coincide with such swells, the combination can be especially destructive.

In San Francisco, Ocean Beach is also expected to see massive waves, but the National Park Service, which manages the beach, has not announced a closure. An NPS spokesperson said in October that shutting down Ocean Beach isn’t practical because of its many access points along 3.5 miles of shoreline.

For Santa Cruz, the decision to close all beaches is a stark reminder of the power of the ocean and the growing risks posed by extreme weather. Residents and visitors are urged to stay off the sand and away from the water until the threat passes. Local officials said they will continue to monitor conditions and may extend the closures if necessary.

The closure of the wharf, a popular tourist destination, is also expected to affect businesses and visitors. City officials asked the public to plan accordingly and to avoid coastal areas entirely during the high-surf event.

Emergency responders are on alert and ready to assist if needed, but officials stressed that the best way to stay safe is to heed the closures. “This is not a time to test the ocean,” Oatey said. “We want everyone to enjoy our coastline safely, and that means staying away until the danger has passed.”