Monroe is a city located in Washington. With a 2020 population of 20,672, it is the 57th largest city in Washington and the 1804th largest city in the United States. Monroe is currently growing at a rate of 2.22% annually and its population has increased by 19.46% since the most recent census, which recorded a population of 17,304 in 2010. Monroe reached it's highest population of 20,672 in 2021. Spanning over 6 miles, Monroe has a population density of 3,392 people per square mile.
The average household income in Monroe is $95,969 with a poverty rate of 7.34%. The median rental costs in recent years comes to $1,391 per month, and the median house value is $357,000. The median age in Monroe is 34 years, 35.1 years for males, and 31.6 years for females. For every 100 females there are 134.3 males.