Monmouth is located in Jackson county Iowa with a geographic area of 0.6 square miles. The total population in Monmouth is 131 with 46.6% male and 53.4% female. Children under age 5 represent 0.0% of the population, under age 18 equal 16.0% of the population and over age 65 is 17.6% of the population. The median household income is $46,250, per capita income is $23,281. There are a total of 58 housing units with 87.9% owner occupied. Education includes 53.4% of residents that are high school graduates and 0.0% with a bachelor's degree or higher. The average temperature in Monmouth in the summer is 71 degrees, and in the winter 23 degrees.