Defiance is located in Defiance county Ohio with a geographic area of 12.7 square miles. The total population in Defiance is 16,741 with 48.7% male and 51.3% female. Children under age 5 represent 6.6% of the population, under age 18 equal 21.6% of the population and over age 65 is 19.7% of the population. The median household income is $50,625, per capita income is $30,919. There are a total of 7,167 housing units with 65.7% owner occupied. Education includes 33.6% of residents that are high school graduates and 21.0% with a bachelor's degree or higher. The average temperature in Defiance in the summer is 72 degrees, and in the winter 32 degrees.