Moss Beach is a coastal census-designated place in San Mateo County, California, with a year 2020 census population of 3,214. Located in Moss Beach are the Fitzgerald Marine Reserve, a marine sanctuary; the Half Moon Bay Airport, the historic Moss Beach Distillery; and the Seal Cove Inn, a destination lodging property. Moss Beach is a cool coastal micr…Moss Beach is a coastal census-designated place in San Mateo County, California, with a year 2020 census population of 3,214. Located in Moss Beach are the Fitzgerald Marine Reserve, a marine sanctuary; the Half Moon Bay Airport, the historic Moss Beach Distillery; and the Seal Cove Inn, a destination lodging property. Moss Beach is a cool coastal microclimate that gives one a sense of separation from the nearby metropolitan San Francisco Bay Area and assures that summer temperatures are generally mild.