Bay st. louis is located in Hancock county Mississippi with a geographic area of 14.7 square miles. The total population in Bay st. louis is 13,539 with 48.3% male and 51.7% female. Children under age 5 represent 6.7% of the population, under age 18 equal 18.5% of the population and over age 65 is 22.8% of the population. The median household income is $43,657, per capita income is $34,736. There are a total of 6,596 housing units with 72.4% owner occupied. Education includes 18.6% of residents that are high school graduates and 33.7% with a bachelor's degree or higher. The average temperature in Bay st. louis in the summer is 79 degrees, and in the winter 44 degrees.