St. Augustine: Demographics & People

St. Augustine is home to 92 people, in 63 households. Population shrank 25.2% from 123 (2022) to 92 (2024). Median age 60.3 years. (17.7y older than Knox County; 21.2y older than Illinois). Children under 18 are 5% of the population. Population is 99% White (non-Hispanic) and 1% Hispanic or Latino. The community is relatively homogeneous (Simpson index 0.06). 35% of households are family-led. County is losing 412 residents per year (2022-2023). County health: 39% adult obesity, 19% smoke.

Population & Trend

Population shrank 25.2% from 123 (2022) to 92 (2024). Estimated 2026 population: ~70 (extrapolated at -12.6%/yr trend). Census Bureau Vintage estimate: 46.

Census data vintage2024
Population49,967 people
Annual growth rate · Population change-25.2%
Annual growth rate · Population (2022)123
Annual growth rate · Population (2024)92
Annual growth rate · Trend categoryshrinking
Population92 people
Population Estimate46

Sources: Census ACS 5-Year 2023, Table B01003  ·  Refreshed 2026-04-12

Age Distribution

Median age 60.3y is 21.4 years older than the U.S. median (38.9y). Children under 18 make up 5% — below the U.S. share of ~22%.

Age Summary · Median age60.3 years (vs Illinois 39.1y)
Age Summary · Children Pct5.4%
Age Summary · Characterretirement community
Population under 185
Median age60.3 years (vs Illinois 39.1y)

Sources: Census ACS 5-Year 2023  ·  Refreshed 2026-04-12

Race, Ethnicity & Diversity

Of 92 residents, race / ethnicity breaks down by Census ACS counts (a person can identify with one or more groups). The Simpson diversity index is 0.06 (0 = single group, 1 = perfectly even distribution); this is read as relatively homogeneous.

White residents122
Hispanic or Latino residents4
Diversity Index · Diversity index (Simpson)6.2%
Diversity Index · Diversity labelrelatively homogeneous
Diversity Index · Groups counted2
Diversity Index · Largest group share96.8%
Hispanic or Latino population1.1%
White (non-Hispanic) population98.9%

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)

(unnamed)
Irish
(unnamed)
German
(unnamed)
Hispanic Total
(unnamed)
Polish
(unnamed)
American
(unnamed)
Puerto Rican
(unnamed)
English
(unnamed)
Cuban

Citizenship & Origin

Where residents were born and their citizenship status (Census ACS).

Residents born in this state85
Residents born in another state6
Share born in this state92.4%
Share born in another state7.6%
Native-born U.S. citizens6.5%
Naturalized citizens1.1%
Total foreign-born residents1

Households & Family Composition

63 households. Averaging 1.9 people each — smaller than the U.S. average of 2.5. 35% are family households — below the U.S. share of ~65%. Of 37 families, 5% are married couples with children.

Children under 1816
Total families37
Married couples with children2
Average household size1.95
Women who gave birth (past year)30.3%
Grandparents living with grandchildren5
Family households22 households
Households that are families34.9%
Total households63 households

Sources: Census ACS 5-Year 2023  ·  Refreshed 2026-04-12

Residential Stability & Migration

How long residents have lived here and where they came from. The surrounding county is losing 412 residents per year on net (IRS migration data).

Lived in same home a year ago92.0%
Migration · People moving in (annual)40,878
Migration · People moving out (annual)41,290
Migration · Net migration (in − out)-412
Migration · Year2022-2023

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 disability17
Disability rate13.6%

Other

Congressional District · District17
Congressional District · FormattedIL-17
Congressional District · Congress118th
Cdc Birth Rate · Fips17,095
Cdc Birth Rate · State Fips17
Cdc Birth Rate · County Fips95
Cdc Birth Rate · CountyKnox
Cdc Birth Rate · Birth Rate21.3%
Cdc Birth Rate · Lower Ci18.10
Cdc Birth Rate · Upper Ci24.90
Cdc Mortality · Fips17,095
Cdc Mortality · CountyKnox County
Cdc Mortality · Urban RuralMicropolitan
Cdc Mortality · Total Deaths 2020 20232,433
Cdc Vaccination · Fips17,095
Cdc Vaccination · CountyKnox County
Cdc Vaccination · Dose1 Pop Pct65.5%
Cdc Vaccination · Series Complete Pct60.6%
Cdc Vaccination · Booster Pct58.6%
Cdc Vaccination · Population 201949,699
Cdc Vaccination · Metro StatusNon-metro
Family Score · Score10
Family Score · Schools20
Family Score · Children Pct5.4%
Family Score · Ratingexcellent
Town Summary · Key Factspopulation 92, shrinking, retirement community, working-class, blue collar
Town Summary · Population92 people
Town Summary · CountyKnox County

Sources: Census place-to-CD118 crosswalk (place_fips) · federal dataset cascade