Eureka is located in Illinois. Eureka, Illinois has a population of 4,908. Eureka is less family-centric than the surrounding county with 29% households with children. The county percentage for households with children is 31%.
The median household income in Eureka, Illinois is $59,464. The median household income for the surrounding county is $74,571 compared to the national median of $66,222. The median age of people living in Eureka is 35.4 years.
The average high temperature in July is 86.02 degrees, with an average low temperature in January of 13.04 degrees. The annual precipitation is 34.78.