Skip to main content

Marshall County, Illinois

Marshall County profile, demographic data, and geographic information.

Marshall County is a county located in Illinois, United States of America. As of official census estimates, it has a reported population of 11,473. The land area covers 386.82 sq mi. [1]

Local Government Administration U.S. Census Bureau GMAF

County Of Marshall County
Official Title: County Clerk
Address: PO BOX 328, LACON IL 61540-0328

Demographics & Population

Demographic Metric Estimate / Count Margin of Error Survey Period / Source
Total Population (2025 PEP Estimate) 11,473 — 2025 / Census
Median Age 46.1 yrs ±0.4 2020-2024 / Census ACS 5-Year 2024
Total Households 5,094 ±159 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 5,815 ±32
Occupied Housing Units 5,094 ±159
Vacant Housing Units 721 ±157
Median Home Value $142,800 ±$8,929
Median Gross Rent $782 ±$84
Source: U.S. Census Bureau ACS 5-Year (2020-2024).

Economy & Workforce

Economic Metric Estimate / Value Margin of Error
Median Household Income $71,585 ±$3,594
Per Capita Income $37,407 ±$1,891
Poverty Rate 11.4% ±1.8%
Population Below Poverty Level 1,296 ±208
Unemployment Rate 3.8% ±1.3%
Civilian Labor Force, Employed 5,158 ±202
Broadband Internet Rate 85.6% ±2.1%
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 LACON, IL US, located 3.9 miles from Marshall County. Local microclimates, topography, and elevation may cause municipal conditions to differ.
Month High (°F) Low (°F) Mean (°F) Precip (in) Snow (in)
January 33.8° 18.0° 25.9° 2.07" 8.1"
February 38.3° 21.5° 29.9° 2.06" 6.2"
March 51.4° 31.3° 41.4° 2.65" 3.2"
April 64.5° 41.4° 52.9° 4.00" 0.7"
May 75.0° 51.7° 63.3° 4.76" 0.0"
June 84.4° 61.2° 72.8° 4.29" 0.0"
July 87.0° 65.1° 76.0° 3.97" 0.0"
August 85.6° 63.0° 74.3° 3.33" 0.0"
September 79.6° 55.1° 67.4° 3.30" 0.0"
October 66.6° 43.5° 55.0° 3.16" 0.1"
November 51.2° 32.6° 41.9° 2.63" 1.1"
December 38.3° 23.2° 30.8° 2.17" 5.2"
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: 17123. • 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.