Martinsburg is located in Berkeley county West virginia with a geographic area of 6.6 square miles. The total population in Martinsburg is 17,517 with 47.2% male and 52.8% female. Children under age 5 represent 6.5% of the population, under age 18 equal 22.0% of the population and over age 65 is 14.8% of the population. The median household income is $44,363, per capita income is $28,329. There are a total of 7,309 housing units with 48.8% owner occupied. Education includes 29.0% of residents that are high school graduates and 26.2% with a bachelor's degree or higher. The average temperature in Martinsburg in the summer is 73 degrees, and in the winter 32 degrees.