Effingham is a city located in Effingham County Illinois. It is also the county seat of Effingham County. With a 2020 population of 12,323, it is the 193rd largest city in Illinois and the 2663rd largest city in the United States . Effingham is currently declining at a rate of -0.76% annually and its population has decreased by -0.04% since the most recent census, which recorded a population of 12,328 in 2010. Effingham reached it's highest population of 12,605 in 2018. Spanning over 10 miles, Effingham has a population density of 1,205 people per square mile.
The average household income in Effingham is $68,927 with a poverty rate of 15.64%. The median rental costs in recent years comes to $599 per month, and the median house value is $126,800. The median age in Effingham is 36.7 years, 36 years for males, and 37.1 years for females.