Ottawa is located in Putnam county Ohio with a geographic area of 4.5 square miles. The total population in Ottawa is 4,349 with 46.1% male and 53.9% female. Children under age 5 represent 6.9% of the population, under age 18 equal 22.7% of the population and over age 65 is 21.2% of the population. The median household income is $45,232, per capita income is $32,624. There are a total of 1,905 housing units with 66.9% owner occupied. Education includes 41.7% of residents that are high school graduates and 22.0% with a bachelor's degree or higher. The average temperature in Ottawa in the summer is 73 degrees, and in the winter 32 degrees.