States · Missouri

Old Jamestown, Missouri.

A community in St. Louis County, with no city government of its own. Zillow publishes no home prices for it.

Living in Old Jamestown, St. Louis County, Missouri

Old Jamestown, in St. Louis County, had 19,790 people in the 2020 census. Half its households earn more than $99,521 a year and half less, against $82,936 across St. Louis County; 7% of its people live below the poverty line. 87% of its homes are lived in by their owners and 13% are rented. Unemployment in St. Louis County was 4.2% in August 2026, and the county had 1.2% fewer jobs in 2025 than the year before. The most residents work in schools and health care, then professional services.

People 19,790 in the 2020 census; median age 41.1
Household income $99,521 the median, give or take $9,587 · St. Louis County: $82,936
Unemployment 4.2% St. Louis County, August 2026; 4.5% a year before
Homes 87% lived in by their owners; 13% rented
  • 7,228households
  • 40%of adults have a degree
  • 7%below the poverty line
  • 29 mintypical commute
  • 23%work from home

What residents work in

  • Schools, hospitals and social care26%
  • Professional and business services13%
  • Manufacturing11%
  • Shops (retail)10%
  • Banks, insurance and property10%
  • Government7%

Employed residents by industry, from the Census survey. St. Louis County had 589,803 jobs in 2025, 1.2% fewer than the year before (Bureau of Labor Statistics).

Weather through the year

Average daily high and low for each month: coldest in January, 40° and 24°; warmest in July, 90° and 71° 20° 40° 60° 80° J 40° 24° F M A M J J 90° 71° A S O N D
Average daily high and low for each month: coldest in January, 40° and 24°; warmest in July, 90° and 71° 20° 40° 60° 80° J 40° 24° F M A M J J 90° 71° A S O N D

Coldest in January, with highs near 40° and lows near 24°; warmest in July, with highs near 90° and lows near 71°. About 17 inches of snow and 42 inches of rain and melted snow a year.

Average daily high and low, 1991–2020, at the St. Louis Lambert International Airport weather station, 7 miles away (NOAA).

Largest workplaces in St. Louis County

  1. Washington University in St LouisUniversity or college20,568
  2. The Boeing CompanyAircraft manufacturing13,947
  3. Graybar Electric CompanyDistribution equipment, electrical, merchant wholesalers7,787
  4. Specl. Sch. Dst. St. Louis CO SchoolsSchool district5,153FTE
  5. Mercy Hospital - St. LouisGeneral hospital5,074FTE
  6. Brinkmann ConstructorsCommercial building construction general contractors4,695
  7. Rockwood R-VI SchoolsSchool district3,388FTE
  8. SSM Health St. Marys Hospital - STLGeneral hospital3,059FTE

Staff on average in 2025, as each workplace reported it to OSHA with its injury records: 995 workplaces with 20 or more staff, 186,284 people in all across the county; Old Jamestown has two of its own. Colleges come from IPEDS (NCES, 2023–24), school districts from the Common Core of Data (NCES, 2023–24) and hospitals from their Medicare cost reports (CMS, 2023); FTE marks full-time equivalent staff. Not listed: many offices and banks, which need not report to OSHA; military bases, whose staff OPM withholds; and, in about half the states, city and county governments.

Natural hazards

  1. Heat wavesVery high
  2. Inland floodingVery high
  3. HailRelatively high
  4. Cold wavesRelatively high
  5. LightningRelatively high
  6. EarthquakesRelatively moderate

FEMA’s National Risk Index (December 2025) rates the risk each natural hazard poses to the people, buildings and farms in Old Jamestown’s census tracts, against the rest of the country; all of them together, relatively high. It is meant for planning, not a substitute for a local risk assessment or a flood map: FEMA’s index.

From the U.S. Census Bureau’s 2020 census and its American Community Survey (2020–2024 five-year estimates), and the Bureau of Labor Statistics. A survey, so each figure has a margin of error, and figures it is not sure of are left out.