Dupo: Demographics & People
Dupo is home to 3,879 people, in 1,598 households. Population shrank 0.9% from 3,914 (2022) to 3,879 (2024). Median age 42.9 years. (3.0y older than St. Clair County; 5.2y older than Illinois). Children under 18 are 20% of the population. Population is 86% White (non-Hispanic) and 6% Black. The community is relatively homogeneous (Simpson index 0.16). 69% of households are family-led. County is losing 126 residents per year (2022-2023). County health: 33% adult obesity, 12% smoke.
- 2.4 people per household (vs Illinois avg 2.5).
- 31% non-family households (singles, roommates) (vs Illinois 38%).
- 54 dependents per 100 working-age (youth + seniors / 18-64) (vs Illinois 64).
Population & Trend
Population shrank 0.9% from 3,914 (2022) to 3,879 (2024). Estimated 2026 population: ~3,844 (extrapolated at -0.4%/yr trend). Census Bureau Vintage estimate: 3,799.
| Census data vintage | 2024 |
|---|---|
| Population | 34,962 people |
| Annual growth rate · Population change | -0.9% |
| Annual growth rate · Population (2022) | 3,914 |
| Annual growth rate · Population (2024) | 3,879 |
| Annual growth rate · Trend category | stable |
| Population | 3,879 people (vs Illinois 39,460) |
| Population Estimate | 3,799 |
Sources: Census ACS 5-Year 2023, Table B01003 · Refreshed 2026-04-12
Age Distribution
Median age 42.9y is 4.0 years older than the U.S. median (38.9y). Children under 18 make up 20% — below the U.S. share of ~22%.
| Age Summary · Median age | 42.9 years (vs Illinois 37.7y) |
|---|---|
| Age Summary · Children Pct | 20.0% |
| Age Summary · Character | established |
| Age Summary · Total Pop | 3,879 |
| Age Summary · Under 18 | 776 |
| Age Summary · 18 To 34 | 974.0× |
| Age Summary · 35 To 64 | 1,553.0× |
| Age Summary · 65 Plus | 576 |
| Population under 18 | 776 |
| Median age | 42.9 years (vs Illinois 37.7y) |
Sources: Census ACS 5-Year 2024 — place-level B01001 query · Census ACS 5-Year 2023 · Refreshed 2026-04-29
Race, Ethnicity & Diversity
Of 3,879 residents, race / ethnicity breaks down by Census ACS counts (a person can identify with one or more groups). The Simpson diversity index is 0.16 (0 = single group, 1 = perfectly even distribution); this is read as relatively homogeneous.
| White residents | 3,406 |
|---|---|
| Black residents | 260 |
| Hispanic or Latino residents | 57 |
| Diversity Index · Diversity index (Simpson) | 15.8% |
| Diversity Index · Diversity label | relatively homogeneous |
| Diversity Index · Groups counted | 3 |
| Diversity Index · Largest group share | 91.5% |
| Asian population | 0.5% (vs Illinois 6.1%) |
| Black population | 5.5% (vs Illinois 9.3%) |
| Hispanic or Latino population | 1.5% (vs Illinois 17.6%) |
| White (non-Hispanic) population | 85.6% (vs Illinois 54.8%) |
Sources: Census ACS 5-Year 2023 · Refreshed 2026-04-12
Ancestry
Self-reported ancestry from Census ACS — what residents report as their ethnic origin, separate from race. Counts can exceed population because people can list multiple ancestries.
Top (8)
Citizenship & Origin
Where residents were born and their citizenship status (Census ACS). 0.4% are foreign-born — below the U.S. average of 13.9%. 1% have naturalized to U.S. citizenship.
| Residents born in this state | 2,055 |
|---|---|
| Residents born in another state | 1,779 |
| Share born in this state | 53.0% |
| Share born in another state | 47.0% |
| Native-born U.S. citizens | 45.9% |
| Foreign-born residents | 0.4% |
| Naturalized citizens | 0.7% |
| Total foreign-born residents | 76 |
Households & Family Composition
1,598 households. Averaging 2.5 people each — matches the U.S. average of 2.5. 69% are family households — above the U.S. share of ~65%. Of 1,011 families, 22% are married couples with children.
| Children under 18 | 730 |
|---|---|
| Total families | 1,011 |
| Married couples with children | 219 |
| Single-parent households | 91 |
| Average household size | 2.48 |
| Women who gave birth (past year) | 14.6% |
| Grandparents living with grandchildren | 202 |
| Grandparents responsible for grandchildren | 21 |
| Family households | 1,105 households (vs Illinois 9,709) |
| Households that are families | 69.1% (vs Illinois 62.4%) |
| Total households | 1,598 households (vs Illinois 14,867) |
Sources: Census ACS 5-Year 2023 · Refreshed 2026-04-12
Residential Stability & Migration
How long residents have lived here and where they came from. 15.1% moved within the county in the past year — the U.S. baseline is roughly 8–10%. The surrounding county is losing 126 residents per year on net (IRS migration data).
| Moved within the county (past year) | 15.1% |
|---|---|
| Migration · People moving in (annual) | 35,076 |
| Migration · People moving out (annual) | 35,202 |
| Migration · Net migration (in − out) | -126 |
| Migration · Year | 2022-2023 |
Sources: IRS SOI Migration 2021-2022 · Refreshed 2026-04-12
Disability
Census ACS measures self-reported functional limitations — vision, hearing, mobility, cognitive, self-care, or independent-living. The U.S. baseline disability rate is about 12–13%; rates trend higher with median age.
| Residents with a disability | 225 |
|---|---|
| Disability rate | 5.7% |
Other
| Congressional District · District | 12 |
|---|---|
| Congressional District · Congress | 118th |
| Cdc Birth Rate · Fips | 17133 |
| Cdc Birth Rate · State Fips | 17 |
| Cdc Birth Rate · County Fips | 133 |
| Cdc Birth Rate · County | Monroe |
| Cdc Birth Rate · Birth Rate | 4.4% |
| Cdc Birth Rate · Lower Ci | 2.90 |
| Cdc Birth Rate · Upper Ci | 6.20 |
| Cdc Mortality · Fips | 17133 |
| Cdc Mortality · County | Monroe County |
| Cdc Mortality · Urban Rural | Large fringe metro |
| Cdc Mortality · Total Deaths 2020 2023 | 795 |
| Cdc Vaccination · Fips | 17133 |
| Cdc Vaccination · County | Monroe County |
| Cdc Vaccination · Dose1 Pop Pct | 70.3% |
| Cdc Vaccination · Series Complete Pct | 64.5% |
| Cdc Vaccination · Booster Pct | 55.3% |
| Cdc Vaccination · Population 2019 | 34,637 |
| Cdc Vaccination · Metro Status | Metro |
| Family Score · Score | 3.10 |
| Family Score · Schools | 3 |
| Family Score · Childcare Centers | 2 |
| Family Score · Children Pct | 20.0% |
| Family Score · Rating | fair |
| Town Summary · Key Facts | population 3,879, stable, established, middle-class, mixed |
| Town Summary · Population | 3,879 people (vs Illinois 39,460) |
| Town Summary · County | Monroe County |
Sources: NCES school congressional district assignment · federal dataset cascade