Erwin is located in Harnett county North carolina with a geographic area of 4.2 square miles. The total population in Erwin is 5,104 with 49.9% male and 50.1% female. Children under age 5 represent 9.1% of the population, under age 18 equal 23.2% of the population and over age 65 is 19.2% of the population. The median household income is $41,702, per capita income is $21,193. There are a total of 1,776 housing units with 62.0% owner occupied. Education includes 36.8% of residents that are high school graduates and 12.2% with a bachelor's degree or higher. The average temperature in Erwin in the summer is 75 degrees, and in the winter 38 degrees.