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St. Charles County, Missouri

St. Charles County profile, demographic data, and geographic information.

St. Charles County is a county located in Missouri, United States of America. As of official census estimates, it has a reported population of 426,499. The land area covers 560.31 sq mi. [1]

Local Government Administration U.S. Census Bureau GMAF

County Of St Charles County
Official Title: County Executive
Address: 100 N 3RD STREET, SUITE 318, SAINT CHARLES MO 63301

Demographics & Population

Demographic Metric Estimate / Count Margin of Error Survey Period / Source
Total Population (2025 PEP Estimate) 426,499 — 2025 / Census
Median Age 39.8 yrs ±0.2 2020-2024 / Census ACS 5-Year 2024
Total Households 161,311 ±694 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 167,163 ±126
Occupied Housing Units 161,311 ±694
Vacant Housing Units 5,852 ±687
Median Home Value $320,800 ±$3,551
Median Gross Rent $1,370 ±$21
Source: U.S. Census Bureau ACS 5-Year (2020-2024).

Economy & Workforce

Economic Metric Estimate / Value Margin of Error
Median Household Income $104,692 ±$1,179
Per Capita Income $51,051 ±$1,117
Poverty Rate 5.2% ±0.4%
Population Below Poverty Level 21,208 ±1,779
Unemployment Rate 2.9% ±0.3%
Civilian Labor Force, Employed 224,065 ±1,762
Broadband Internet Rate 95.1% ±0.4%
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 ST PETERS 2 SE, MO US, located 4.7 miles from St. Charles County. Local microclimates, topography, and elevation may cause municipal conditions to differ.
Month High (°F) Low (°F) Mean (°F) Precip (in) Snow (in)
January 39.3° 21.2° 30.2° 2.44" 4.7"
February 44.9° 24.8° 34.8° 2.37" 5.0"
March 55.5° 33.3° 44.4° 3.46" 1.5"
April 67.3° 43.3° 55.3° 4.74" 0.1"
May 76.3° 53.5° 64.9° 4.80" 0.0"
June 84.4° 63.3° 73.9° 4.26" 0.0"
July 88.1° 67.5° 77.8° 4.23" 0.0"
August 87.2° 65.4° 76.3° 3.76" 0.0"
September 80.8° 57.1° 68.9° 3.07" 0.0"
October 68.5° 45.2° 56.9° 3.11" 0.0"
November 54.9° 35.0° 44.9° 3.54" 0.8"
December 43.6° 26.5° 35.0° 2.56" 2.7"
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: 29183. • 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.