Monongahela is a city located in Pennsylvania. With a 2020 population of 4,101, it is the 240th largest city in Pennsylvania and the 5325th largest city in the United States. Monongahela is currently declining at a rate of -0.36% annually and its population has decreased by -4.63% since the most recent census, which recorded a population of 4,300 in 2010. Monongahela reached it's highest population of 8,922 in 1950. Spanning over 2 miles, Monongahela has a population density of 2,144 people per square mile.
The average household income in Monongahela is $59,886 with a poverty rate of 10.64%. The median rental costs in recent years comes to $591 per month, and the median house value is $79,100. The median age in Monongahela is 46 years, 42 years for males, and 49.2 years for females. For every 100 females there are 91.5 males.