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Carroll County, Illinois

Carroll County profile, demographic data, and geographic information.

Carroll County is a county located in Illinois, United States of America. As of official census estimates, it has a reported population of 15,419. The land area covers 445.41 sq mi. [1]

Local Government Administration U.S. Census Bureau GMAF

County Of Carroll County
Official Title: Treasurer
Address: PO BOX 198, MOUNT CARROLL IL 61053-0198

Demographics & Population

Demographic Metric Estimate / Count Margin of Error Survey Period / Source
Total Population (2025 PEP Estimate) 15,419 — 2025 / Census
Median Age 45.4 yrs ±0.5 2020-2024 / Census ACS 5-Year 2024
Total Households 6,578 ±242 2020-2024 / Census ACS 5-Year 2024
Source: U.S. Census Bureau (PEP, ACS 5-Year).

Housing & Real Estate Profile

Housing Metric Estimate / Value Margin of Error
Total Housing Units 8,204 ±41
Occupied Housing Units 6,578 ±242
Vacant Housing Units 1,626 ±246
Median Home Value $114,500 ±$5,896
Median Gross Rent $818 ±$38
Source: U.S. Census Bureau ACS 5-Year (2020-2024).

Economy & Workforce

Economic Metric Estimate / Value Margin of Error
Median Household Income $60,758 ±$2,707
Per Capita Income $32,110 ±$1,478
Poverty Rate 14.2% ±2.3%
Population Below Poverty Level 1,976 ±316
Unemployment Rate 3.1% ±1%
Civilian Labor Force, Employed 6,473 ±236
Broadband Internet Rate 86.1% ±2.6%
Source: U.S. Census Bureau ACS 5-Year (2020-2024).

Climate & Weather Observations

NOAA Monthly Climate Normals

Observation Station: Climate data reflects NOAA 1991–2020 standard normals recorded at MT CARROLL, IL US, located 3.6 miles from Carroll County. Local microclimates, topography, and elevation may cause municipal conditions to differ.
Month High (°F) Low (°F) Mean (°F) Precip (in) Snow (in)
January 30.7° 10.9° 20.8° 1.66" 10.2"
February 35.3° 14.3° 24.8° 1.83" 7.9"
March 47.5° 25.7° 36.6° 2.51" 3.6"
April 60.6° 35.8° 48.2° 3.90" 0.8"
May 72.3° 47.3° 59.8° 4.57" 0.0"
June 81.7° 57.0° 69.4° 5.49" 0.0"
July 84.9° 60.4° 72.6° 4.89" 0.0"
August 83.3° 58.1° 70.7° 3.91" 0.0"
September 76.9° 49.6° 63.3° 3.71" 0.0"
October 63.9° 38.3° 51.1° 3.02" 0.4"
November 48.5° 27.4° 38.0° 2.60" 1.7"
December 35.8° 17.1° 26.4° 2.21" 8.8"
Source: NOAA U.S. Climate Normals (1991–2020).

Local Weather Forecast

Weather forecast data is currently unavailable in the local cache.

Sources & Data Provenance

  1. Geographic Classification & Identifiers: U.S. Census Bureau Gazetteer (2026) and TIGER/Line Shapefiles. GEOID: 17015. • Official Source Dataset →
  2. Socioeconomic & Housing Metrics: U.S. Census Bureau American Community Survey (ACS) 5-year estimates and Population Estimates Program (PEP). Margin of Error (MOE) intervals are reported where published; suppressed values are never estimated or replaced with false zeros.
  3. Civic Directory Datasets: Centers for Medicare & Medicaid Services (CMS Hospital Directory), National Center for Education Statistics (NCES IPEDS Postsecondary Directory), and Institute of Museum and Library Services (IMLS Public Libraries Survey). Airport landing facilities are provided by airport-data.com.
  4. Weather & Climate Observations: National Oceanic and Atmospheric Administration (NOAA) U.S. Climate Normals 1991–2020 and National Weather Service (NWS) point forecasts.