Decatur is located in Adams county Indiana with a geographic area of 6.1 square miles. The total population in Decatur is 9,700 with 50.9% male and 49.1% female. Children under age 5 represent 7.3% of the population, under age 18 equal 21.9% of the population and over age 65 is 18.7% of the population. The median household income is $46,287, per capita income is $24,171. There are a total of 4,353 housing units with 64.0% owner occupied. Education includes 45.3% of residents that are high school graduates and 13.0% with a bachelor's degree or higher. The average temperature in Decatur in the summer is 73 degrees, and in the winter 29 degrees.