Village · Illinois
Lenzburg, Illinois
Lenzburg, village, in St. Clair County, Illinois. Lenzburg had 436 residents on July 1, 2025 by the Census Bureau's estimate, down 4.8% since 2020; the 2020 Census counted 468 and the ACS 2020-2024 5-year estimates put it at 428 (±146). GEOID 1742860.
Residents, July 2025 estimate
436
Census Bureau estimate (no margin published)
2020 Census count: 468 · ACS 2020-2024: 428 ±146
Median household income
$42,656
±$8,061 (90% margin)
Illinois: $83,390
Median home value
$77,900
±$38,000 (90% margin)
Illinois: $263,300
Median gross rent
$669
±$381 (90% margin)
Illinois: $1,274
Where is Lenzburg and what county is it in?
Lenzburg is a village in St. Clair County, Illinois. It covers 1.2 square miles of land, 405 residents per square mile in 2020.
Lenzburg is in the St. Louis, MO-IL metropolitan statistical area, which takes in 15 counties (Census Bureau delineation, July 2023).
Lenzburg lies entirely within Lenzburg Township, a township with its own local government (2020 census blocks).
Source: 2024 Gazetteer and 2020 place-by-county files, U.S. Census Bureau · Census reference files
How many people live in Lenzburg, and is it growing?
The Census Bureau estimates that 436 people lived in Lenzburg on July 1, 2025, down 4.8% since 2020, a steeper fall than Illinois's (−0.8%). The 2020 Census counted 468 residents. The 2020-2024 American Community Survey, a five-year sample, puts the population at 428 (±146).
| Measure | Lenzburg | St. Clair County | Change since 2015-2019 |
|---|---|---|---|
| Total population | 428 ±146 | 253,694 | no clear change |
| Households | 165 ±54 | 100,846 | no clear change |
| Average household size | 2.59 ±0.55 | 2.47 | no clear change |
| Housing units | 189 ±55 | 115,630 | no clear change |
Lenzburg's population since 2000
From 577 in 2000 to 436 in 2025: down 24.4%. The 2000, 2010 and 2020 figures are census counts, each for Lenzburg as it was drawn that year: a place that annexed land, or a community that has since incorporated, covered a different area then. The 2005 figure is the Census Bureau's intercensal estimate, revised to fit the 2000 and 2010 counts and drawn on 2010 boundaries; 2015 and 2025 are July 1 estimates made from the census before them.
Source: The 2000, 2010 and 2020 Census counts and the Census Bureau's population estimates (intercensal 2000-2010, Vintage 2020, Vintage 2025) · Census population estimates
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); Census PEP Vintage 2025 (SUB-EST2025, CO-EST2025); 2020 Census P.L. 94-171 · Check it at data.census.gov
Who lives in Lenzburg?
The median resident of Lenzburg is 32.0 years old; 31.8% are under 18 and 11.2% are 65 or older. The largest group is non-Hispanic white residents at 92.5%, then non-Hispanic residents of two or more races at 4.0%.
| Measure | Lenzburg | St. Clair County | Change since 2015-2019 |
|---|---|---|---|
| Median age | 32.0 ±9.8 | 39.9 | no clear change |
| Under 18 years | 31.8% ±10.7 pts | 23.0% | – |
| 65 years and over | 11.2% ±5.7 pts | 17.3% | – |
| Male | 45.6% ±6.4 pts | 48.5% | – |
| Hispanic or Latino (any race) | 3.0% ±4.6 pts | 5.1% | – |
| White alone, not Hispanic | 92.5% ±5.5 pts | 59.1% | no clear change |
| Black or African American alone, not Hispanic | 0.2% ±0.6 pts | 27.7% | – |
| Asian alone, not Hispanic | 0.0% ±8.4 pts | 1.6% | – |
| American Indian and Alaska Native alone, not Hispanic | 0.2% ±0.5 pts | 0.2% | – |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.0% ±8.4 pts | 0.0% | – |
| Two or more races, not Hispanic | 4.0% ±3.3 pts | 5.8% | – |
| Some other race alone, not Hispanic | 0.0% ±8.4 pts | 0.5% | – |
| Born outside the United States | 0.5% ±0.9 pts | 3.3% | – |
| Speak a language other than English at home (age 5+) | 10.5% ±13.9 pts | 5.0% | – |
| Civilian veterans (age 18+) | 11.3% ±6.9 pts | 11.5% | – |
| With a disability | 18.7% ±7.3 pts | 15.2% | – |
| No health insurance coverage | 21.7% ±17.1 pts | 5.1% | – |
| High school graduate or higher (age 25+) | 83.5% ±11.9 pts | 93.5% | – |
| Bachelor's degree or higher (age 25+) | 14.2% ±6.3 pts | 31.8% | no clear change |
| Graduate or professional degree (age 25+) | 5.0% ±3.6 pts | 13.8% | – |
| Lived in the same house a year earlier | 96.9% ±2.9 pts | 88.3% | – |
| Moved from another state in the past year | 0.9% ±1.3 pts | 3.0% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profiles DP02, DP05) · Check it at data.census.gov
What do households in Lenzburg earn?
Half of Lenzburg's 165 households earn less than $42,656 a year (±$8,061), against $73,854 in St. Clair County and $83,390 in Illinois. In 2015-2019 it was $49,043 in 2024 dollars; the margins of error cannot tell the two periods apart. 21.6% of residents live below the poverty line.
| Measure | Lenzburg | St. Clair County | Change since 2015-2019 |
|---|---|---|---|
| Median household income | $42,656 ±$8,061 | $73,854 | no clear change |
| Mean household income | $62,898 ±$13,866 | $96,049 | – |
| Per capita income | $25,320 ±$6,812 | $38,942 | no clear change |
| People below the poverty line | 21.6% ±9.4 pts | 13.6% | – |
| Children under 18 below the poverty line | 30.2% ±21.3 pts | 18.9% | – |
| Households receiving SNAP | 33.9% ±11.8 pts | 16.2% | – |
| Households with a computer | 88.5% ±10.5 pts | 94.2% | – |
| Households with a broadband subscription | 79.4% ±13.1 pts | 89.7% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What does housing cost in Lenzburg?
Owners occupy 63.6% of Lenzburg's occupied homes and renters 36.4%. The median owner-occupied home is valued at $77,900 by its owner (±$38,000). The median renter pays $669 a month including utilities, and 47.2% of renters pay 35% or more of their income on rent.
| Measure | Lenzburg | St. Clair County | Change since 2015-2019 |
|---|---|---|---|
| Median home value (owner-occupied) | $77,900 ±$38,000 | $180,300 | no clear change |
| Median gross rent | $669 ±$381 | $1,090 | no clear change |
| Renters paying 35% or more of income on rent | 47.2% ±21.6 pts | 39.8% | – |
| Median monthly owner costs, with a mortgage | $1,149 ±$122 | $1,645 | – |
| Owner-occupied homes | 63.6% ±11.5 pts | 68.4% | no clear change |
| Renter-occupied homes | 36.4% ±11.5 pts | 31.6% | – |
| Housing units | 189 ±55 | 115,630 | no clear change |
| Homeowner vacancy rate | 0.9% ±2.2 pts | 1.1% | – |
| Rental vacancy rate | 0.0% ±41.1 pts | 4.7% | – |
| Single-family detached homes | 72.0% ±9.0 pts | 72.1% | – |
| Mobile homes | 18.5% ±7.9 pts | 4.4% | – |
| Built 2020 or later | 0.0% ±17.9 pts | 0.9% | – |
| Built 2010 to 2019 | 1.1% ±2.1 pts | 7.3% | – |
| Built 1939 or earlier | 28.0% ±9.8 pts | 13.5% | – |
| Households with no vehicle | 12.7% ±11.4 pts | 7.5% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP04) · Check it at data.census.gov
How do people in Lenzburg work and get to work?
88.4% of Lenzburg's workers drive alone. The average trip to work takes 30.2 minutes.
| Measure | Lenzburg | St. Clair County | Change since 2015-2019 |
|---|---|---|---|
| In the labor force (age 16+) | 58.7% ±9.1 pts | 63.4% | – |
| Unemployment rate | 5.5% ±4.6 pts | 6.0% | – |
| Drove alone to work | 88.4% ±5.8 pts | 75.4% | – |
| Carpooled | 2.4% ±3.1 pts | 8.1% | – |
| Public transportation | 0.0% ±20.3 pts | 1.6% | – |
| Walked | 1.8% ±2.5 pts | 1.5% | – |
| Worked from home | 4.9% ±3.3 pts | 12.4% | – |
| Mean travel time to work | 30.2 min ±4.8 | 24.0 min | no clear change |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What census tracts are in Lenzburg?
No census tract lies mostly in Lenzburg; 1 tract reaches into it (2020 census blocks).
| Tract | Residents, 2020-2024 | Median household income |
|---|---|---|
| Tract 5040.02St. Clair County | 5,136 | $78,235 |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); 2020 block assignment files (tract share = share of the tract's census blocks in Lenzburg) · Census block assignment files
How does Lenzburg compare with other places in Illinois?
By the Census Bureau's July 2025 estimates, Lenzburg is the 13,763rd-most populous of the 19,476 U.S. incorporated places that have one and the 908th-most populous of 1,294 in Illinois.
Lenzburg is not ranked by income or the other survey measures: those rankings include places of 1,000 or more residents (2020 Census) with a reliable estimate.
| Measure | Rank | Of |
|---|---|---|
| Population, July 2025 estimate | 908th | 1,294 |
Lenzburg's figures with every place in Illinois (CSV)
Every place in Illinois, sortable · Compare Lenzburg with other places
Source: PlainCities ranks computed from the American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) and PEP Vintage 2025 · How ranks are computed
How reliable are the figures for Lenzburg?
23 of the 57 figures for Lenzburg on this page carry a coefficient of variation over 40% and are marked with a ring: they come from a small sample, so read them as rough.
The American Community Survey samples about one household in eight over five years, so every figure is an estimate with a 90% margin of error (shown under each value). A ring marks an estimate whose coefficient of variation is over 40%. A change is called only when the gap between the two periods is larger than their combined 90% margin (the square root of the sum of the two squared margins), the Census Bureau's test. How to read a margin of error.
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026): margins of error as published · ACS technical documentation
How these figures are made: methodology and release checks · reading a margin of error · every state · corrections
Not on this page: crime, weather and schools for Lenzburg are other agencies' records. Crime: the FBI's Crime Data Explorer · climate: NOAA's U.S. Climate Normals · schools: the National Center for Education Statistics' public schools in Lenzburg.