Bethel island is located in Contra costa county California with a geographic area of 5.3 square miles. The total population in Bethel island is 2,015 with 48.9% male and 51.1% female. Children under age 5 represent 4.2% of the population, under age 18 equal 15.5% of the population and over age 65 is 23.8% of the population. The median household income is $62,019, per capita income is $32,162. There are a total of 837 housing units with 79.2% owner occupied. Education includes 30.1% of residents that are high school graduates and 18.8% with a bachelor's degree or higher. The average temperature in Bethel island in the summer is 76 degrees, and in the winter 43 degrees.
