Marengo, Illinois Demographics & Population 2026
During the 2020–2024 ACS period, Marengo, Illinois had a total population of 7,040, the 282nd largest city in Illinois, with a median household income of $73,523, which is 12% lower than the state average. The poverty rate is 15.7%.
Data vintage: U.S. Census Bureau ACS 2020–2024 5-Year Estimates · refreshed July 2026 · Methodology & source notes
Key Takeaways
- Unemployment rate of 9.8% is notably above the national average.
Marengo Quick Facts
How Marengo Changed
Change from the 2019–2023 ACS period to 2020–2024. These are rolling five-year estimates, not year-over-year measurements.
| Metric | 2019–2023 | 2020–2024 | Change |
|---|---|---|---|
| Population | 7,123 | 7,040 | -1.2% |
| Median household income | $72,586 | $73,523 | +1.3% |
| Median home value | $206,100 | $229,900 | +11.5% |
How Marengo Compares
Median Household Income
Median Home Value
Economy & Housing
Household Income Distribution
Detailed income brackets
Employment
Housing Overview
People & Demographics
Age Distribution
Race & Ethnicity
Diversity Index
A less diverse community where one racial or ethnic group represents a large majority.
State average: 61 | National average: 61
Education
Educational Attainment (Adults 25+)
Marengo Rankings in Illinois
Explore Illinois Rankings
Other Cities in McHenry County
| City | Population | Median Income | Poverty | Home Value |
|---|---|---|---|---|
| Crystal Lake | 40,579 | $108,418 | 6.8% | $311,400 |
| Lake in the Hills | 28,800 | $117,151 | 4.1% | $321,900 |
| McHenry | 28,074 | $86,315 | 4.7% | $266,500 |
| Woodstock | 26,147 | $82,758 | 6.0% | $245,700 |
| Cary | 17,923 | $113,026 | 4.8% | $309,800 |
| Harvard | 9,598 | $67,617 | 11.8% | $175,400 |
| Johnsburg | 6,386 | $121,023 | 12.1% | $328,300 |
| Spring Grove | 5,917 | $134,210 | 1.4% | $398,400 |
| Lakewood | 4,707 | $173,625 | 3.5% | $552,600 |
| Wonder Lake | 4,292 | $94,655 | 2.9% | $252,200 |
Cities Similar to Marengo
These cities in the same state have comparable population and economic profiles.
| City | Population | Median Income | Home Value | Bachelor's+ | Poverty |
|---|---|---|---|---|---|
| Robinson | 7,084 | $73,993 | $109,100 | 25.4% | 9.6% |
| University Park | 7,306 | $73,844 | $153,200 | 26.5% | 14.4% |
| North Riverside | 7,249 | $77,170 | $297,800 | 42.9% | 7.9% |
| Jerseyville | 7,445 | $73,529 | $143,900 | 19.1% | 12.3% |
| Stickney | 6,952 | $66,942 | $244,900 | 23.2% | 12.3% |
Population Overview
Marengo is a small city located in Illinois, within McHenry County. The total population is 7,040. It ranks as the 282nd most populous out of 1,445 Census-designated places in Illinois.
Age Demographics
The median age in Marengo is 31.9 years. This is 18% lower than the state median of 39.0 years.
Economy, Income & Housing
The median household income in Marengo is $73,523. This is 12% lower than the state median of $83,390. It is also 9% lower than the national median of $80,734. The poverty rate stands at 15.7%. This is 33% higher than the state poverty rate of 11.8%. The unemployment rate is 9.8%. This is 68% higher than the state rate of 5.8%. The median home value is $229,900. Housing costs are 13% lower than the state median of $263,300. The home-value-to-income ratio is 3.1x. 63.1% of occupied housing units are owner-occupied. This homeownership rate is 6% lower than the state average of 67.1%.
Race & Ethnicity
Marengo has a predominantly White (non-Hispanic) population, comprising 85.3% of all residents. Hispanic or Latino residents account for 11.3%. The Black or African American population (0.4%) is well below the state average of 13.3%. The Asian population (0.1%) is well below the state average of 5.9%.
Education
15.4% of residents aged 25 and older hold a bachelor's degree or higher. This is 59% lower than the state rate of 37.9%. Nationally, 35.7% of adults hold at least a bachelor's degree. The high school graduation rate (or equivalent) is 95.0%.
Data Sources & Methodology
All demographic data for Marengo, Illinois is sourced from the U.S. Census Bureau's American Community Survey (ACS) 2020–2024 5-Year Estimates. The ACS collects data from approximately 3.5 million households annually and pools five years of responses so that even small communities can be measured, though the margin of error widens as the population falls. Comparisons are made against Illinois state averages and national averages calculated from the same dataset. Rankings reflect the city's position among all 1,445 Census-designated places in Illinois. Read more about how these figures are produced on our methodology page, or visit data.census.gov for official data.
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Frequently Asked Questions
What is the population of Marengo, Illinois?
Marengo, Illinois has a population of 7,040 according to the most recent U.S. Census ACS 5-Year Estimates.
What is the median household income in Marengo, IL?
The median household income in Marengo is $73,523, which is 9% lower than the national median of $80,734.
What is the poverty rate in Marengo, IL?
The poverty rate in Marengo is 15.7%. This means approximately 1,098 residents live below the federal poverty line.
What is the racial makeup of Marengo, Illinois?
Marengo's population is 85.3% White, 0.4% Black, 11.3% Hispanic/Latino, and 0.1% Asian.
What is the median home value in Marengo, IL?
The median home value in Marengo is $229,900. The home-value-to-income ratio is 3.1x.
How educated is Marengo, Illinois?
15.4% of adults (25+) in Marengo hold a bachelor's degree or higher, and 2.2% hold a graduate or professional degree.