Eureka, Illinois

Eureka population, 2020 to 2024

Eureka lost 28 residents from July 2020 to July 2024, a change of -0.5%. In the latest year it moved by -18. Among 330 Illinois places of 5,000 or more, that growth ranks 148th; the median place changed by -0.9%. The median place of 5,000+ in Illinois has 14,760 people, so Eureka is 35% of it.

Eureka covers 2.74 square miles of land and 0.05 of water, for 1,894 people per square mile of land. The median Illinois place of 5,000+ has 2,177, so Eureka is less dense than the typical town.

What county Eureka is in

All of Eureka's residents live in Woodford County, which had 38,290 residents in 2024. Eureka holds 13.6% of the county's population. The shaded shape is on the map above; dots mark the eight nearest places.

ZIP codes in Eureka

1 ZIP Code Tabulation Area (ZCTA) overlaps Eureka by at least 10% of the ZCTA's or the city's land: 61530. ZCTAs are Census approximations of USPS ZIP code delivery areas. The list comes from the 2020 ZCTA to place relationship file, so a city that annexed land after 2020 may reach into ZIP codes not listed here.

Where Eureka is

The Census internal point of Eureka is at 40.714000, -89.277000. Springfield, the capital, is 67.4 miles SSW in a straight line. The nearest larger place is Washington, IL (15,857 people), 8.2 miles away. The nearest city of 100,000 or more is Peoria, IL, 18.0 miles away.

Daylight in Eureka

At 40.71° N, Eureka gets about 15 h 06 min of daylight around the June solstice and 9 h 15 min around the December solstice, a swing of 5 h 51 min. Figures are sunrise to sunset from the SunCalc model for June 21 and December 21, 2026.

Places near Eureka

The eight nearest incorporated places of 1,000+ in Illinois, measured between internal points. The closest is Roanoke, 7.1 miles away, with 1,928 people.