Port st. john is located in Brevard county Florida with a geographic area of 9.3 square miles. The total population in Port st. john is 23,940 with 49.5% male and 50.5% female. Children under age 5 represent 4.5% of the population, under age 18 equal 20.3% of the population and over age 65 is 15.2% of the population. The median household income is $66,948, per capita income is $33,446. There are a total of 8,745 housing units with 89.1% owner occupied. Education includes 24.2% of residents that are high school graduates and 24.7% with a bachelor's degree or higher. The average temperature in Port st. john in the summer is 80 degrees, and in the winter 56 degrees.