Jefferson

County:: Union County
County Seat:: No
Area (mi²):: 0.51
State:: South Dakota

Jefferson is a city located in Union County, South Dakota. Jefferson has a 2025 population of 431. Jefferson is currently declining at a rate of -1.82% annually and its population has decreased by -8.88% since the most recent census, which recorded a population of 473 in 2020.

The average household income in Jefferson is $78,129 with a poverty rate of 3.21%. The median age in Jefferson is 34 years: 33.6 years for males, and 38.5 years for females.

Demographics

The racial composition of Jefferson includes 90.24% White, 4.18% Native American, and smaller percentages for other race, Black or African American, Asian, Native Hawaiian or Pacific Islander and multiracial populations.

Population by Race

White

Native American

Two or more races

Other race

Black or African American

Asian

Native Hawaiian or Pacific Islander

Race	Population	Percentage (of total)
White	647	90.24%
Native American	30	4.18%
Two or more races	23	3.21%
Other race	17	2.37%
Black or African American	0	0%
Asian	0	0%
Native Hawaiian or Pacific Islander	0	0%

Jefferson Marital Status

Married

Widowed

Divorced

Separated

Never Married

Economics and Income Statistics

Jefferson's average per capita income is $41,250. Household income levels show a median of $81,149. The poverty rate stands at 3.21%.

Families: A family includes the owner or renter of the home along with everyone related to them - whether through birth, marriage, or adoption. This includes relatives like spouses, children, parents, siblings, grandparents, and any other family members.

Households: A household includes all the people who occupy a housing unit (such as a house or apartment) as their usual place of residence.

Non Families: A nonfamily household is either someone living alone or when the owner/renter lives with people they aren't related to, like roommates.

Name	Median	Mean
Married Families	$85,750	-
Families	$81,554	$84,363
Households	$81,149	$78,129
Non Families	$50,000	$62,464

$41,250

Average Income

$81,149

Median Household Income

3.21%

Poverty Rate