Seneca is located in La salle county Illinois with a geographic area of 6.4 square miles. The total population in Seneca is 2,534 with 48.8% male and 51.2% female. Children under age 5 represent 8.8% of the population, under age 18 equal 26.3% of the population and over age 65 is 11.9% of the population. The median household income is $74,907, per capita income is $34,832. There are a total of 950 housing units with 83.8% owner occupied. Education includes 32.4% of residents that are high school graduates and 16.4% with a bachelor's degree or higher. The average temperature in Seneca in the summer is 74 degrees, and in the winter 27 degrees.
