The population density was 2,832.7 people per square mile (1,093.4/km²).There were 11,461 housing units at an average density of 1,159.2 per square mile (447.4/km²).Monsoon clouds do occur, usually during late July through early September.
Fair Oaks is known for its mix of suburban and semi-rural neighborhoods.
According to the United States Census Bureau, the CDP has a total area of 11.2 square miles (29 km) of it (4.02%) is water.
There were 761 (5.9%) unmarried opposite-sex partnerships, and 109 (0.8%) same-sex married couples or partnerships.
3,304 households (25.7%) were made up of individuals and 1,304 (10.2%) had someone living alone who was 65 years of age or older. There were 8,564 families (66.7% of all households); the average family size was 2.84. For every 100 females age 18 and over, there were 92.2 males.
Chilling tule fog events have been known to last for several consecutive days or weeks.