Buffalo Grove is a city located in Lake County Illinois. With a 2020 population of 39,932, it is the 41st largest city in Illinois and the 984th largest city in the United States . Buffalo Grove is currently declining at a rate of -0.70% annually and its population has decreased by -3.77% since the most recent census, which recorded a population of 41,496 in 2010. Buffalo Grove reached it's highest population of 42,909 in 2000. Spanning over 10 miles, Buffalo Grove has a population density of 4,210 people per square mile.
The average household income in Buffalo Grove is $140,449 with a poverty rate of 3.36%. The median rental costs in recent years comes to $1,643 per month, and the median house value is $332,300. The median age in Buffalo Grove is 41.7 years, 40.8 years for males, and 42.4 years for females.