South River is a city located in Middlesex County New Jersey. With a 2020 population of 15,441, it is the 60th largest city in New Jersey and the 2276th largest city in the United States . South River is currently declining at a rate of -1.08% annually and its population has decreased by -3.54% since the most recent census, which recorded a population of 16,008 in 2010. South River reached it's highest population of 16,145 in 2014. Spanning over 3 miles, South River has a population density of 5,544 people per square mile.
The average household income in South River is $91,783 with a poverty rate of 7.21%. The median rental costs in recent years comes to $1,288 per month, and the median house value is $299,600. The median age in South River is 37.4 years, 36.5 years for males, and 38.6 years for females.