Illiopolis is a village in Sangamon County, Illinois, home to about 890 people across 0.7 square miles. Its ZIP code is 62539.
Homes sold for a median of $73 per square foot in the three months ending August 2026.
Mostly Illiopolis
Each card is that ZIP code’s whole market, including any part outside Illiopolis. Seller’s market: under 4 months of supply; buyer’s market: over 6. Methodology
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| Nearest major airport | St. Louis Lambert International Airport (STL)97 miles away |
|---|---|
| Closer regional airport | Decatur Airport (DEC)20 miles away |
| Nearest city of 250,000+ | St. Louis, MO99 miles away |
| Nearest city of 1 million+ | Chicago, IL160 miles away |
Straight-line distances from the center of Illiopolis; driving is longer.
Source: Airports from OurAirports (scheduled passenger service); city centers and populations from the U.S. Census Bureau.
Source: Members of Congress from the congress-legislators project; districts from the Census Bureau’s relationship files; governor and mayor from Wikidata.
Illiopolis had 846 residents in the 2020 census, down 8% since 2000.
It’s the 736th largest of 1,450 towns in Illinois by population.
Sangamon County grew from 71,593 residents in 1900 to 196,343 in 2020.
Sangamon County, 1900–2020
Source: U.S. Census Bureau decennial censuses (counties 1900–1990 from the Bureau’s historical county file).
Average highs peak around 85°F in summer, and winter lows average 20°F. About 40.4 inches of rain and melted snow fall in a typical year, with about 14 inches of snow.
Source: NOAA 1991–2020 climate normals, Decatur Wtp, IL weather station (16 miles away).
80,005 jobs at 4,925 businesses in Sangamon County. The biggest industries by employees:
Source: U.S. Census Bureau County Business Patterns 2023 (private employers; jobs counted where people work).
Nearest hospitals
Source: Hospitals from CMS Hospital General Information (ratings are CMS overall star ratings); straight-line distances.
Parks (1 nearby)
Grocery stores (1 nearby)
Libraries (1 nearby)
Counts are within about 1 mile of the center of town.
Source: Map data © OpenStreetMap contributors (openstreetmap.org/copyright), as mapped by volunteers; it can miss places or include closed ones.
Public schools here are run by Sangamon Valley CUSD 9. Check each district’s attendance zones for a specific address.
| School | Grades | Students | Type | Distance |
|---|---|---|---|---|
| Sangamon Valley Intermediate SchIlliopolis | 3–5 | 115 | Public | 0.3 mi |
| Sangamon Valley Middle SchoolIlliopolis | 6–8 | 145 | Public | 0.3 mi |
Source: U.S. Department of Education, NCES: Common Core of Data (2024-2025) for public schools. Listed by address; we don’t rate schools.
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Town boundaries don’t always match ZIP codes: a ZIP code can cross into neighboring towns, and a town can share a ZIP code with its neighbors. Facts describe the town itself; market figures describe whole ZIP codes.