An urgent small craft advisory was issued Saturday afternoon by the National Weather Service.
"Currently, wind gusts are reading over 30 mph and greater," San Francisco Fire Department Capt. Jonathan Baxter said on Twitter. "Please consider land-based recreational activities today."
Twelve people have been rescued in the city's coastal areas by SFFD and the U.S. Coast Guard. None suffered injuries, according to Baxter.
Two kite surfers near Point Lobos on the city's west side, two kayakers off Pier 70 and eight kayakers—six aged between 11 and 15—by Oracle Park were all rescued by SFFD, Coast Guard and two fishermen, according to Baxter.
"Inexperienced mariners, especially those operating smaller vessels, should avoid navigating in hazardous conditions," the weather service advises.
The small craft advisory ends at 3 a.m. Sunday.