Mountlake Terrace is a city located in Washington. With a 2020 population of 21,278, it is the 55th largest city in Washington and the 1765th largest city in the United States. Mountlake Terrace is currently declining at a rate of -0.14% annually but its population has increased by 6.88% since the most recent census, which recorded a population of 19,909 in 2010. Mountlake Terrace reached it's highest population of 21,368 in 2018. Spanning over 4 miles, Mountlake Terrace has a population density of 5,246 people per square mile.
The average household income in Mountlake Terrace is $87,769 with a poverty rate of 7.33%. The median rental costs in recent years comes to $1,464 per month, and the median house value is $392,600. The median age in Mountlake Terrace is 37.3 years, 36.6 years for males, and 38.3 years for females. For every 100 females there are 97.0 males.