• county
  • FIPS 19101
  • Largest town: Fairfield

Jefferson County, Iowa

Jefferson County had 15,781 residents in the Census Vintage 2024 estimate, on 435.5 square miles of land. It ranks 48th of 99 in Iowa by population and 81st by land area.

Population
15,781
#48 of 99 in Iowa · #2,050 in US
Area
435.5 sq mi
#81 of 99 in Iowa · #2,326 in US
Density
36 / sq mi
#31 of 99 in Iowa · #1,766 in US
Median household income
$58,146
#96 of 99 in Iowa · #2,015 in US

Census Vintage 2024 estimates · SAIPE 2023 income · 2024 Gazetteer land area

Jefferson County within Iowa. Pin: Des Moines.

Measure from here

Tools and pages that start from Jefferson County

Jefferson County population, land area and income

Jefferson County had 15,781 residents in the Census Vintage 2024 estimate, on 435.5 square miles of land. It ranks 48th of 99 in Iowa by population and 81st by land area. That works out to 36.2 people per square mile, below the US average of 96.3, and below the national county median.

The median county-equivalent in Iowa has 15,008 residents, about the same as Jefferson County.

Its SAIPE 2023 median household income of $58,146 is below the national county median among 3,143 counties with an estimate.

National rank among 3,144

Population

15,781

3144th1st

2050th of 3,144 (US)

Land area

436 sq mi

3144th1st

2326th of 3,144 (US)

Density

36.2 / sq mi

3144th1st

1766th of 3,144 (US)

Median household income

$58,146

3143rd1st

2015th of 3,143 (US)

Rank within Iowa (99)

Population

15,781

99th1st

48th of 99 (IA)

Land area

436 sq mi

99th1st

81st of 99 (IA)

Density

36.2 / sq mi

99th1st

31st of 99 (IA)

Median household income

$58,146

99th1st

96th of 99 (IA)

How Jefferson County's population changed since 2020

Jefferson County gained 82 residents between the July 2020 and July 2024 estimates, a rise of 0.5%. That ranks 32nd of 99 in Iowa for growth. The median Iowa county changed by -0.6%, and the state as a whole by +1.6%.

Since the April 2020 estimates base, Jefferson County recorded 610 births and 836 deaths, a natural change of -226. Net international migration added +1,149 and net domestic migration, people moving to or from other US counties, came to -836. The largest single component was international migration, which added 1,149 people.

15.7k202015.8k202115.6k202215.6k202315.8k2024
Census Vintage 2024 county estimates for July 1 of each year. The axis starts above zero so year-to-year changes are visible.

Components of change, April 2020 to July 2024

Births
610
Deaths
836
Net international migration
+1,149
Net domestic migration
-836
Change, July 2023 to July 2024
+155

Where Jefferson County is

The Census internal point of Jefferson County is at 41.006400, -91.966600. It sits in UTM zone 15N. The map shades Iowa's 99 county-equivalents by population change from 2020 to 2024, darker for faster growth, with Jefferson County outlined. Dots are towns of 1,000+ people with residents in it.

Monroe County: -2.9%Worth County: -1.7%Buena Vista County: +0.0%Jasper County: +0.8%Van Buren County: -0.0%Hardin County: -2.2%Ida County: -3.1%Marshall County: +0.8%Fayette County: -1.5%Ringgold County: -0.8%Wapello County: +1.0%Webster County: -0.2%Adams County: -2.8%Buchanan County: +0.6%Cerro Gordo County: -1.2%Lucas County: +1.6%Emmet County: -1.9%Floyd County: -3.8%Crawford County: -0.7%Linn County: +0.6%Montgomery County: -2.6%Polk County: +4.7%Cherokee County: +0.0%Bremer County: +1.3%Grundy County: +0.5%Adair County: -0.8%Cedar County: -1.4%Story County: +3.9%Mahaska County: -0.6%Davis County: +0.9%Clay County: +0.8%Johnson County: +4.6%Greene County: -1.0%Palo Alto County: -2.0%Benton County: +1.0%Cass County: -0.7%Wright County: -1.5%Audubon County: -2.1%Henry County: -5.3%Boone County: +0.1%Appanoose County: -1.4%Washington County: +0.4%Chickasaw County: -2.2%Poweshiek County: -0.9%Osceola County: -2.6%Wayne County: +1.8%Mitchell County: +0.4%Jefferson County: +0.5%Union County: -1.4%Butler County: -1.2%Hancock County: -1.3%Marion County: +1.9%Delaware County: +0.9%Humboldt County: +0.2%Sioux County: +1.8%Des Moines County: -1.1%O'Brien County: +0.8%Clayton County: -0.6%Black Hawk County: +1.0%Winnebago County: -2.6%Harrison County: +0.4%Decatur County: -1.0%Pocahontas County: -0.9%Lyon County: +3.8%Iowa County: -1.4%Franklin County: +0.3%Dickinson County: +2.2%Madison County: +3.2%Allamakee County: +0.8%Jones County: +2.2%Carroll County: -1.6%Kossuth County: -2.6%Hamilton County: -1.0%Howard County: -1.4%Page County: -1.1%Guthrie County: +1.5%Tama County: -1.8%Monona County: -3.6%Clarke County: -2.1%Lee County: -3.4%Mills County: +2.1%Sac County: -2.7%Scott County: +0.6%Keokuk County: -1.6%Jackson County: -0.3%Warren County: +7.1%Calhoun County: -1.9%Shelby County: +0.8%Fremont County: -1.1%Dubuque County: -0.1%Louisa County: -1.8%Taylor County: -0.6%Woodbury County: +1.2%Clinton County: -0.9%Winneshiek County: -1.6%Pottawattamie County: -0.1%Plymouth County: +0.5%Muscatine County: -2.4%Dallas County: +14.7%
Change 2020 to 2024
  1. < -1.9%
  2. < -1.0%
  3. < +0.0%
  4. < +0.9%
  5. ≥ +0.9%
no data

Orange pin: Jefferson County internal point. Dark pin: Des Moines.

Internal point

Decimal
41.006400, -91.966600
DMS
41°00'23.04"N 91°57'59.76"W
UTM
15N 586902.8E 4539981.8N
Geohash
9zq970zzw
Plus code
86HC224M+H9

Towns in Jefferson County

One incorporated place of 1,000+ people has residents in Jefferson County, 9,511 people together, or 60% of the county. Each figure counts only the part of the town inside Jefferson County; towns marked "part" extend into another county. The largest is Fairfield with 9,511.

  1. 01Fairfield9,511
Census Vintage 2024 subcounty estimates, county parts of incorporated places (SUMLEV 157).

Counties bordering Jefferson County

The Census 2024 county adjacency file lists 6 neighbors for Jefferson County. The most populous is Wapello County, IA, with 35,681 residents. Distances run between Census internal points in a straight line.

Distance to Des Moines and the nearest big city

Des Moines is 94.1 miles WNW of Jefferson County's internal point in a straight line. The nearest place of 100,000 or more is Cedar Rapids, IA (population 137,904), 67.9 miles away. The nearest place of 10,000 or more is Ottumwa, IA (population 25,648), 23.9 miles away.

Jefferson County FIPS code

The FIPS code of Jefferson County is 19101: state code 19 for Iowa plus county code 101. Use it as text, with the leading zero, when joining Census, BLS, or CDC county tables. SAIPE lists its 2023 median household income as $58,146.

Questions people ask

What is the population of Jefferson County, Iowa?

The Census Vintage 2024 estimate for July 1, 2024 is 15,781. That is up 82 people (0.5%) from the July 2020 estimate of 15,699.

What is the FIPS code of Jefferson County?

19101. The first two digits (19) are Iowa; the last three (101) identify the county.

What is the largest town in Jefferson County?

Fairfield, with 9,511 residents inside Jefferson County in 2024.

Which counties border Jefferson County?

6 county-equivalents border it in the Census 2024 adjacency file: Wapello County, IA; Washington County, IA; Henry County, IA; Keokuk County, IA; Davis County, IA; Van Buren County, IA.

Sources and data as of

Data as of: Census Vintage 2024 population estimates, 2024 Gazetteer land area and internal points, SAIPE 2023 median household income.

  1. 01Census Vintage 2024 county population estimates
  2. 02Census 2024 Gazetteer, counties
  3. 03Census SAIPE 2023 state and county estimates
  4. 04Census Vintage 2024 subcounty population estimates
  5. 05Census 2024 county adjacency file
  6. 06Census 2024 cartographic boundary file, counties (1:5,000,000)

How every number is computed: methodology. Spotted a wrong figure? Report an error.