The average household size was 1.94 and the average family size was 2.51. For every 100 females age 18 and over, there were 75.3 males.
The population density was 363.8 people per square mile (140.2/km²).
There were 549 housing units at an average density of 242.4 per square mile (93.4/km²).
Since 1987, Mendocino has been the site of the Mendocino Music Festival, a classically based but musically diverse series of concerts that is held annually in a huge circus-type performance tent on the town's Main Street in the Mendocino Headlands State Park. Mendocino has a cool summer Maritime Mediterranean climate.
Summers are characterized by frequent fog and highs mostly in the upper sixties and lows in the fifties.
The racial makeup of the CDP was 95.51% White, 0.36% Native American, 1.09% Asian, 0.73% from other races, and 2.31% from two or more races.
Hispanic or Latino of any race were 2.79% of the population.
This region experiences warm (but not hot) and dry summers, with no average monthly temperatures above 71.6 °F.
According to the Köppen Climate Classification system, Mendocino has a warm-summer Mediterranean climate, abbreviated "Csb" on climate maps. The population density was 120.5 people per square mile (46.5/km²).
Mendocino Presbyterian Church on Main Street, dedicated on July 5, 1868, is one of the oldest continuously used Protestant churches in California, and is designated as California Historical Landmark #714.