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St. Mary Parish, Louisiana

St. Mary Parish profile, demographic data, and geographic information.

St. Mary Parish is a county located in Louisiana, United States of America. As of official census estimates, it has a reported population of 46,552. The land area covers 558.53 sq mi. [1]

Local Government Administration U.S. Census Bureau GMAF

Parish Of St Mary County
Official Title: Chief Administrative Officer
Address: 500 MAIN ST, 5TH FLOOR COURTHOUSE, FRANKLIN LA 70538-6157

Demographics & Population

Demographic Metric Estimate / Count Margin of Error Survey Period / Source
Total Population (2025 PEP Estimate) 46,552 — 2025 / Census
Median Age 39.7 yrs ±0.6 2020-2024 / Census ACS 5-Year 2024
Total Households 18,463 ±468 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 22,507 ±85
Occupied Housing Units 18,463 ±468
Vacant Housing Units 4,044 ±477
Median Home Value $138,900 ±$8,393
Median Gross Rent $848 ±$36
Source: U.S. Census Bureau ACS 5-Year (2020-2024).

Economy & Workforce

Economic Metric Estimate / Value Margin of Error
Median Household Income $52,576 ±$3,030
Per Capita Income $28,265 ±$1,551
Poverty Rate 20.8% ±2.6%
Population Below Poverty Level 9,809 ±1,218
Unemployment Rate 5.4% ±1.8%
Civilian Labor Force, Employed 19,135 ±846
Broadband Internet Rate 87.4% ±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 FRANKLIN 3 NW, LA US, located 14.2 miles from St. Mary Parish. Local microclimates, topography, and elevation may cause municipal conditions to differ.
Month High (°F) Low (°F) Mean (°F) Precip (in) Snow (in)
January 62.7° 43.7° 53.2° 5.63" 0.0"
February 66.7° 47.5° 57.1° 4.00" 0.0"
March 72.4° 52.8° 62.6° 4.02" 0.0"
April 77.9° 59.0° 68.4° 4.67" 0.0"
May 83.9° 66.8° 75.4° 4.68" 0.0"
June 88.4° 72.4° 80.4° 7.63" 0.0"
July 89.8° 74.2° 82.0° 8.01" 0.0"
August 90.2° 73.9° 82.0° 7.62" 0.0"
September 87.3° 70.0° 78.6° 5.59" 0.0"
October 80.4° 60.2° 70.3° 4.26" 0.0"
November 71.5° 50.1° 60.8° 4.22" 0.0"
December 65.0° 45.5° 55.2° 4.94" 0.0"
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: 22101. • 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.