San Francisco’s October tide reached a record high Saturday, with a gauge at Crissy Field measuring water 1.62 feet above the average highest daily tide. The reading topped the previous October record, set last year, by 0.22 feet and exceeded the National Weather Service forecast by more than 0.2 feet. The unusually high water brought local impacts. The northbound Highway 101 off-ramp in Mill Valley closed at about 12:25 p.m., the California Highway Patrol reported. Incident logs said at least one vehicle became trapped in floodwater, which also inundated a nearby park-and-ride lot. At south Ocean Beach, waves surged toward the dunes near Sloat Boulevard. Water reached levels more commonly seen during major winter storms, prompting a weekend beach hazards statement and coastal flood advisory. October usually has relatively modest tides because of the positions of the moon and sun. Saturday’s water level was closer to the winter king tides, which scientists say could reach record heights along the California coast and in San Francisco Bay this winter as El Niño develops. Warmer ocean water expands and occupies more volume, contributing to higher water levels. Human-caused climate change is also raising seas over the long term, adding to the risks facing the region’s shoreline. The October record follows unusually high tides recorded in June and July, when water levels were respectively 1.97 feet and 1.89 feet above the average daily tide. During the strong 2015-16 El Niño, high water and frequent storms eroded parts of Ocean Beach by as much as 180 feet; U.S. Geological Survey research found coastal erosion was 76% above normal along the West Coast that winter. “Our beaches are huge right now, and they’re going to be a lot smaller by the end of winter,” said Chase Davenport, director of the Ocean Beach Institute. He said the southern end of Ocean Beach is likely to keep narrowing, adding: “We’re going to have to adapt.”