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St. Clair County, Michigan

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

St. Clair County is a county located in Michigan, United States of America. As of official census estimates, it has a reported population of 160,486. The land area covers 721.52 sq mi. [1]

Local Government Administration U.S. Census Bureau GMAF

County Of St Clair County
Official Title: Chairman
Address: 200 GRAND RIVER AVE, STURE 203, PORT HURON MI 48060

Demographics & Population

Demographic Metric Estimate / Count Margin of Error Survey Period / Source
Total Population (2025 PEP Estimate) 160,486 — 2025 / Census
Median Age 44.5 yrs ±0.2 2020-2024 / Census ACS 5-Year 2024
Total Households 67,816 ±583 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 72,799 ±121
Occupied Housing Units 67,816 ±583
Vacant Housing Units 4,983 ±560
Median Home Value $224,600 ±$3,575
Median Gross Rent $1,029 ±$25
Source: U.S. Census Bureau ACS 5-Year (2020-2024).

Economy & Workforce

Economic Metric Estimate / Value Margin of Error
Median Household Income $71,270 ±$1,351
Per Capita Income $38,214 ±$1,024
Poverty Rate 11.3% ±0.9%
Population Below Poverty Level 17,872 ±1,412
Unemployment Rate 5.7% ±0.7%
Civilian Labor Force, Employed 75,692 ±1,037
Broadband Internet Rate 90.9% ±0.7%
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 RICHMOND 4 NNW, MI US, located 7.3 miles from St. Clair County. Local microclimates, topography, and elevation may cause municipal conditions to differ.
Month High (°F) Low (°F) Mean (°F) Precip (in) Snow (in)
January 30.1° 16.2° 23.2° 2.37" 10.8"
February 32.8° 16.1° 24.4° 1.92" 13.3"
March 42.1° 24.9° 33.5° 2.09" 6.1"
April 56.2° 35.5° 45.8° 3.19" 2.6"
May 68.5° 47.4° 57.9° 3.81" 0.0"
June 78.4° 57.6° 68.0° 3.56" 0.0"
July 83.0° 62.1° 72.5° 3.94" 0.0"
August 80.0° 59.4° 69.7° 3.27" 0.0"
September 73.1° 51.9° 62.5° 3.46" 0.0"
October 60.3° 41.1° 50.7° 2.95" 0.0"
November 46.5° 31.7° 39.1° 2.97" 3.5"
December 35.4° 23.1° 29.3° 2.37" 10.3"
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: 26147. • 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.