County Dossier

Johnson County

Illinois | County

Population

13,376

Land Area

343.7 sq mi

Context

Nonmetro

Geography

County silhouette

Land Area
343.7 sq mi
Water Area
4.9 sq mi
Water Share
1.4%

Terrain Layer

Open the county terrain view inside the atlas flow.

Terra Firma

Population & Housing

Population

13,376

Density
38.9 / sq mi
Households
4,101
Housing Units
5,541
Median Age
41.4 years

Income & Economy

Median Household Income

$62,528

GDP

$328.89M

Real GDP Change+4.4%
Per Capita Income
$27,765
Personal Income
$586.91M
Personal Income Per Capita
$44,062

Classification

RUCC 8
Nonmetro

Urban population of fewer than 5,000, adjacent to a metro area

Relief

Min

237 ft

Mean

501 ft

Max

857 ft

Provenance

GEOID 17087 ANSI 00424245
Latitude 37.46071 Longitude -88.88213
Canonical 2025 Gazetteer ACS ACS 2020-2024 5-year BEA BEA county 2024 release (2026-02-05) BLS BLS LAUS 2024 annual average USDA USDA RUCC 2023 USGS USGS 3DEP published as of 2026-03-23