Seneca is located in Illinois. Seneca, Illinois has a population of 2,569. Seneca is less family-centric than the surrounding county with 22.85% of the households containing married families with children. The county average for households married with children is 27.78%.
The median household income in Seneca, Illinois is $67,351. The median household income for the surrounding county is $54,693 compared to the national median of $57,652. The median age of people living in Seneca is 37.8 years.
The average high temperature in July is 83.9 degrees, with an average low temperature in January of 13.8 degrees. The average rainfall is approximately 37.5 inches per year, with 23.7 inches of snow per year.
