Monroe is located in Snohomish county Washington with a geographic area of 6.1 square miles. The total population in Monroe is 19,403 with 56.3% male and 43.7% female. Children under age 5 represent 7.8% of the population, under age 18 equal 23.0% of the population and over age 65 is 9.2% of the population. The median household income is $88,683, per capita income is $29,664. There are a total of 5,498 housing units with 67.7% owner occupied. Education includes 20.7% of residents that are high school graduates and 24.9% with a bachelor's degree or higher. The average temperature in Monroe in the summer is 63 degrees, and in the winter 42 degrees.