Fairmont City: Demographics & People
2,492 people call Fairmont City home, in 881 households. Population grew 5.9% from 2,354 (2022) to 2,492 (2024). Median age 38.9 years. (1.0y younger than St. Clair County; 1.2y older than Illinois). Children under 18 are 27% of the population. Population is 75% Hispanic or Latino and 17% White (non-Hispanic). The community is moderately diverse (Simpson index 0.47). 64% of households are family-led. County is gaining 956 residents per year (2022-2023). County health: 36% adult obesity, 15% smoke.
- 2.8 people per household (vs Illinois avg 2.5).
- 36% non-family households (singles, roommates) (vs Illinois 38%).
- 77 dependents per 100 working-age (youth + seniors / 18-64) (vs Illinois 64).
Population & Trend
Population grew 5.9% from 2,354 (2022) to 2,492 (2024) — about 9.8× the recent U.S. annual rate of ~0.6%/yr. Estimated 2026 population: ~2,640 (extrapolated at 2.9%/yr trend). Census Bureau Vintage estimate: 2,846.
| Census data vintage | 2024 |
|---|---|
| Population | 265,859 people |
| Annual growth rate · Population change | 5.9% |
| Annual growth rate · Population (2022) | 2,354 |
| Annual growth rate · Population (2024) | 2,492 |
| Annual growth rate · Population growing | Yes |
| Annual growth rate · Trend category | booming |
| Population | 2,492 people (vs Illinois 39,460) |
| Population Estimate | 2,846 |
Sources: Census ACS 5-Year 2023, Table B01003 · Refreshed 2026-04-12
Age Distribution
Median age 38.9y is 0.0 years matches the U.S. median (38.9y). Children under 18 make up 27% — above the U.S. share of ~22%.
| Age Summary · Median age | 38.9 years (vs Illinois 37.7y) |
|---|---|
| Age Summary · Children Pct | 26.9% |
| Age Summary · Character | family-oriented |
| Age Summary · Total Pop | 2,492 |
| Age Summary · Under 18 | 671 |
| Age Summary · 18 To 34 | 458.0× |
| Age Summary · 35 To 64 | 947.0× |
| Age Summary · 65 Plus | 416 |
| Population under 18 | 671 |
| Median age | 38.9 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 2,492 residents, race / ethnicity breaks down by Census ACS counts (a person can identify with one or more groups). The Simpson diversity index is 0.47 (0 = single group, 1 = perfectly even distribution); this is read as moderately diverse.
| White residents | 767 |
|---|---|
| Black residents | 49 |
| Asian residents | 29 |
| Hispanic or Latino residents | 1,657 |
| Diversity Index · Diversity index (Simpson) | 46.7% |
| Diversity Index · Diversity label | moderately diverse |
| Diversity Index · Groups counted | 4 |
| Diversity Index · Largest group share | 66.2% |
| Black population | 2.1% (vs Illinois 9.3%) |
| Hispanic or Latino population | 75.4% (vs Illinois 17.6%) |
| White (non-Hispanic) population | 16.7% (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). 8.5% are foreign-born — below the U.S. average of 13.9%. 22% have naturalized to U.S. citizenship.
| Residents born in this state | 1,408 |
|---|---|
| Residents born in another state | 316 |
| Share born in this state | 56.5% |
| Share born in another state | 43.5% |
| Native-born U.S. citizens | 12.7% |
| Foreign-born residents | 8.5% |
| Naturalized citizens | 22.3% |
| Total foreign-born residents | 486 |
Households & Family Composition
881 households. Averaging 2.7 people each — larger than the U.S. average of 2.5. 64% are family households — near the U.S. share of ~65%. Of 528 families, 37% are married couples with children.
| Children under 18 | 572 |
|---|---|
| Total families | 528 |
| Married couples with children | 196 |
| Single-parent households | 22 |
| Average household size | 2.68 |
| Women who gave birth (past year) | 16.4% |
| Grandparents living with grandchildren | 134 |
| Grandparents responsible for grandchildren | 134 |
| Family households | 566 households (vs Illinois 9,709) |
| Households that are families | 64.2% (vs Illinois 62.4%) |
| Total households | 881 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. 2.6% moved within the county in the past year — the U.S. baseline is roughly 8–10%. The surrounding county is gaining 956 residents per year on net (IRS migration data).
| Moved within the county (past year) | 2.6% |
|---|---|
| Migration · People moving in (annual) | 237,226 |
| Migration · People moving out (annual) | 236,270 |
| Migration · Net migration (in − out) | 956 |
| Migration · Population growing | Yes |
| 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 | 158 |
|---|---|
| Disability rate | 7.4% |
Other
| Congressional District · District | 13 |
|---|---|
| Congressional District · Formatted | IL-13 |
| Congressional District · Congress | 118th |
| Cdc Birth Rate · Fips | 17119 |
| Cdc Birth Rate · State Fips | 17 |
| Cdc Birth Rate · County Fips | 119 |
| Cdc Birth Rate · County | Madison |
| Cdc Birth Rate · Birth Rate | 17.0% |
| Cdc Birth Rate · Lower Ci | 15.60 |
| Cdc Birth Rate · Upper Ci | 18.60 |
| Cdc Mortality · Fips | 17119 |
| Cdc Mortality · County | Madison County |
| Cdc Mortality · Urban Rural | Large fringe metro |
| Cdc Mortality · Total Deaths 2020 2023 | 10,097 |
| Cdc Vaccination · Fips | 17119 |
| Cdc Vaccination · County | Madison County |
| Cdc Vaccination · Dose1 Pop Pct | 71.4% |
| Cdc Vaccination · Series Complete Pct | 64.6% |
| Cdc Vaccination · Booster Pct | 53.6% |
| Cdc Vaccination · Population 2019 | 262,966 |
| Cdc Vaccination · Metro Status | Metro |
| Family Score · Score | 10 |
| Family Score · Schools | 20 |
| Family Score · Children Pct | 26.9% |
| Family Score · Rating | excellent |
| Town Summary · Key Facts | population 2,492, booming, family-oriented, working-class, mixed |
| Town Summary · Population | 2,492 people (vs Illinois 39,460) |
| Town Summary · County | Madison County |
Sources: Census place-to-CD118 crosswalk (place_fips) · federal dataset cascade