Jefferson is located in Greene county Iowa with a geographic area of 6.0 square miles. The total population in Jefferson is 4,121 with 45.3% male and 54.7% female. Children under age 5 represent 5.5% of the population, under age 18 equal 20.5% of the population and over age 65 is 27.5% of the population. The median household income is $44,215, per capita income is $30,664. There are a total of 1,995 housing units with 66.1% owner occupied. Education includes 31.6% of residents that are high school graduates and 25.3% with a bachelor's degree or higher. The average temperature in Jefferson in the summer is 72 degrees, and in the winter 23 degrees.
