• county
  • FIPS 46127
  • Largest town: North Sioux City

Union County, South Dakota

Union County had 17,402 residents in the Census Vintage 2024 estimate, on 460.8 square miles of land. It ranks 13th of 66 in South Dakota by population and 62nd by land area.

Population
17,402
#13 of 66 in South Dakota · #1,958 in US
Area
460.8 sq mi
#62 of 66 in South Dakota · #2,227 in US
Density
38 / sq mi
#8 of 66 in South Dakota · #1,723 in US
Median household income
$97,016
#2 of 66 in South Dakota · #164 in US

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

Union County within South Dakota. Pin: Pierre.

Measure from here

Tools and pages that start from Union County

Union County population, land area and income

Union County had 17,402 residents in the Census Vintage 2024 estimate, on 460.8 square miles of land. It ranks 13th of 66 in South Dakota by population and 62nd by land area. That works out to 37.8 people per square mile, below the US average of 96.3, and below the national county median.

The median county-equivalent in South Dakota has 5,296 residents, so Union County is 3.3 times that size.

Its SAIPE 2023 median household income of $97,016 is in the top tenth among 3,143 counties with an estimate.

National rank among 3,144

Population

17,402

3144th1st

1958th of 3,144 (US)

Land area

461 sq mi

3144th1st

2227th of 3,144 (US)

Density

37.8 / sq mi

3144th1st

1723rd of 3,144 (US)

Median household income

$97,016

3143rd1st

164th of 3,143 (US)

Rank within South Dakota (66)

Population

17,402

66th1st

13th of 66 (SD)

Land area

461 sq mi

66th1st

62nd of 66 (SD)

Density

37.8 / sq mi

66th1st

8th of 66 (SD)

Median household income

$97,016

66th1st

2nd of 66 (SD)

How Union County's population changed since 2020

Union County gained 545 residents between the July 2020 and July 2024 estimates, a rise of 3.2%. That ranks 13th of 66 in South Dakota for growth. The median South Dakota county changed by +0.8%, and the state as a whole by +4.1%.

Since the April 2020 estimates base, Union County recorded 813 births and 615 deaths, a natural change of +198. Net international migration added +90 and net domestic migration, people moving to or from other US counties, came to +296. The largest single component was domestic migration, which added 296 people.

16.9k202016.9k202117.1k202217.2k202317.4k2024
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
813
Deaths
615
Net international migration
+90
Net domestic migration
+296
Change, July 2023 to July 2024
+216

Where Union County is

The Census internal point of Union County is at 42.831100, -96.650800. It sits in UTM zone 14N. The map shades South Dakota's 66 county-equivalents by population change from 2020 to 2024, darker for faster growth, with Union County outlined. Dots are towns of 1,000+ people with residents in it.

Davison County: -0.2%Minnehaha County: +5.5%Bennett County: -3.0%Clark County: +3.2%Hamlin County: +7.1%Jerauld County: +2.8%Brule County: +0.2%Aurora County: +0.4%Turner County: +4.6%Beadle County: +1.5%Hand County: -1.6%Kingsbury County: +1.0%McCook County: +1.7%Miner County: -0.0%Lyman County: +0.5%Codington County: +3.3%Deuel County: +0.8%Sully County: +1.1%Oglala Lakota County: -2.1%Edmunds County: +0.8%Sanborn County: +2.7%Spink County: -3.7%Lake County: -0.1%Hyde County: -3.0%Potter County: -2.9%Perkins County: -0.6%Faulk County: +0.5%Day County: -0.5%Clay County: +1.6%Hanson County: +0.5%Fall River County: +5.5%Brookings County: +5.9%Yankton County: +1.0%Hutchinson County: -0.1%Butte County: +5.8%Custer County: +11.8%Lawrence County: +11.5%Hughes County: -1.2%Grant County: +1.0%Brown County: -1.9%Gregory County: +2.8%Campbell County: -2.8%Bon Homme County: +1.4%McPherson County: -4.0%Lincoln County: +14.6%Stanley County: +1.5%Walworth County: -0.5%Harding County: +1.3%Marshall County: +2.3%Union County: +3.2%Pennington County: +5.8%Buffalo County: -5.8%Moody County: +3.0%Tripp County: +2.0%Roberts County: +0.2%Charles Mix County: -0.3%Meade County: +3.4%Haakon County: -1.8%Jones County: -5.3%Douglas County: +0.5%Dewey County: +1.9%Corson County: -3.6%Mellette County: -4.6%Todd County: -1.6%Jackson County: -2.4%Ziebach County: +1.0%
Change 2020 to 2024
  1. < -1.8%
  2. < +0.2%
  3. < +1.3%
  4. < +3.2%
  5. ≥ +3.2%
no data

Orange pin: Union County internal point. Dark pin: Pierre.

Internal point

Decimal
42.831100, -96.650800
DMS
42°49'51.96"N 96°39'2.88"W
UTM
14N 692007.2E 4744735.8N
Geohash
9ze78tjj1
Plus code
86J5R8JX+CM

Towns in Union County

3 incorporated places of 1,000+ people have residents in Union County, 6,861 people together, or 39% of the county. Each figure counts only the part of the town inside Union County; towns marked "part" extend into another county. The largest is North Sioux City with 3,059.

  1. 01North Sioux City3,059
  2. 02Elk Point2,074
  3. 03Beresford (part)1,728
Census Vintage 2024 subcounty estimates, county parts of incorporated places (SUMLEV 157).

Counties bordering Union County

The Census 2024 county adjacency file lists 7 neighbors for Union County, including 5 across a state line. The most populous is Woodbury County, IA, with 107,257 residents. Distances run between Census internal points in a straight line.

Distance to Pierre and the nearest big city

Pierre is 213.2 miles WNW of Union County's internal point in a straight line. The nearest place of 100,000 or more is Sioux Falls, SD (population 209,289), 49.2 miles away. The nearest place of 10,000 or more is Vermillion, SD (population 11,877), 14.4 miles away.

Union County FIPS code

The FIPS code of Union County is 46127: state code 46 for South Dakota plus county code 127. Use it as text, with the leading zero, when joining Census, BLS, or CDC county tables. SAIPE lists its 2023 median household income as $97,016.

Questions people ask

What is the population of Union County, South Dakota?

The Census Vintage 2024 estimate for July 1, 2024 is 17,402. That is up 545 people (3.2%) from the July 2020 estimate of 16,857.

What is the FIPS code of Union County?

46127. The first two digits (46) are South Dakota; the last three (127) identify the county.

What is the largest town in Union County?

North Sioux City, with 3,059 residents inside Union County in 2024.

Which counties border Union County?

7 county-equivalents border it in the Census 2024 adjacency file: Woodbury County, IA; Lincoln County, SD; Sioux County, IA; Plymouth County, IA; Dakota County, NE; Clay County, SD; Dixon County, NE.

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.