Duncan is located in Spartanburg county South carolina with a geographic area of 5.2 square miles. The total population in Duncan is 3,556 with 42.6% male and 57.4% female. Children under age 5 represent 8.4% of the population, under age 18 equal 29.8% of the population and over age 65 is 9.9% of the population. The median household income is $50,000, per capita income is $20,019. There are a total of 1,336 housing units with 40.6% owner occupied. Education includes 19.5% of residents that are high school graduates and 16.5% with a bachelor's degree or higher. The average temperature in Duncan in the summer is 77 degrees, and in the winter 43 degrees.
