St. John: Demographics & People

Census counts 607 people in St. John, in 275 households. Population shrank 11.4% from 685 (2022) to 607 (2024). Median age 57.3 years. (30.9y older than Whitman County; 18.8y older than Washington). Children under 18 are 13% of the population. Population is 89% White (non-Hispanic) and 4% Asian. The community is relatively homogeneous (Simpson index 0.17). 48% of households are family-led. County is losing 535 residents per year (2022-2023). County health: 31% adult obesity, 15% smoke.

Population & Trend

Population shrank 11.4% from 685 (2022) to 607 (2024). Estimated 2026 population: ~539 (extrapolated at -5.7%/yr trend). Census Bureau Vintage estimate: 457.

Census data vintage2024
Population47,973 people
Annual growth rate · Population change-11.4%
Annual growth rate · Population (2022)685
Annual growth rate · Population (2024)607
Annual growth rate · Trend categoryshrinking
Population607 people
Population Estimate457

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

Age Distribution

Median age 57.3y is 18.4 years older than the U.S. median (38.9y). Children under 18 make up 13% — below the U.S. share of ~22%.

Age Summary · Median age57.3 years (vs Washington 38.5y)
Age Summary · Children Pct12.7%
Age Summary · Characterretirement community
Population under 1877
Median age57.3 years (vs Washington 38.5y)

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

Race, Ethnicity & Diversity

Of 607 residents, race / ethnicity breaks down by Census ACS counts (a person can identify with one or more groups). The Simpson diversity index is 0.17 (0 = single group, 1 = perfectly even distribution); this is read as relatively homogeneous.

White residents601
Black residents51
Asian residents3
Hispanic or Latino residents7
Diversity Index · Diversity index (Simpson)17.0%
Diversity Index · Diversity labelrelatively homogeneous
Diversity Index · Groups counted4
Diversity Index · Largest group share90.8%
Asian population4.4%
Black population0.5%
Hispanic or Latino population1.6%
White (non-Hispanic) population89.3%

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

Citizenship & Origin

Where residents were born and their citizenship status (Census ACS). 1.2% are foreign-born — below the U.S. average of 13.9%. 5% have naturalized to U.S. citizenship.

Residents born in this state355
Residents born in another state216
Share born in this state58.5%
Share born in another state41.5%
Native-born U.S. citizens35.6%
Foreign-born residents1.2%
Naturalized citizens4.8%
Total foreign-born residents15
From Africa4

Households & Family Composition

275 households. Averaging 2.4 people each — matches the U.S. average of 2.5. 48% are family households — below the U.S. share of ~65%. Of 157 families, 23% are married couples with children.

Children under 18132
Total families157
Married couples with children36
Single-parent households3
Average household size2.41
Women who gave birth (past year)29.6%
Grandparents living with grandchildren166
Grandparents responsible for grandchildren59
Family households132 households
Households that are families48.0%
Total households275 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. 6.3% moved within the county in the past year — the U.S. baseline is roughly 8–10%. The surrounding county is losing 535 residents per year on net (IRS migration data).

Moved within the county (past year)6.3%
Migration · People moving in (annual)36,276
Migration · People moving out (annual)36,811
Migration · Net migration (in − out)-535
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 disability65
Disability rate10.7%

Group Quarters

Group quarters are non-household living arrangements counted by the Census — college dormitories, nursing homes, military barracks, group homes, correctional facilities, and similar institutional or shared housing. 45 residents live in group quarters (7.4% of population).

Living in group quarters45

Other

Congressional District · District5
Congressional District · FormattedWA-05
Congressional District · Congress118th
Cdc Birth Rate · Fips53,075
Cdc Birth Rate · State Fips53
Cdc Birth Rate · County Fips75
Cdc Birth Rate · CountyWhitman
Cdc Birth Rate · Birth Rate2.2%
Cdc Birth Rate · Lower Ci1.60
Cdc Birth Rate · Upper Ci3.00
Cdc Mortality · Fips53,075
Cdc Mortality · CountyWhitman County
Cdc Mortality · Urban RuralMicropolitan
Cdc Mortality · Total Deaths 2020 20231,036
Cdc Vaccination · Fips53,075
Cdc Vaccination · CountyWhitman County
Cdc Vaccination · Dose1 Pop Pct62.3%
Cdc Vaccination · Series Complete Pct50.6%
Cdc Vaccination · Booster Pct56.6%
Cdc Vaccination · Population 201950,104
Cdc Vaccination · Metro StatusNon-metro
Family Score · Score10
Family Score · Schools20
Family Score · Children Pct12.7%
Family Score · Ratingexcellent
Town Summary · Key Factspopulation 607, shrinking, retirement community, working-class, mixed
Town Summary · Population607 people
Town Summary · CountyWhitman County

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