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 and multiracial populations.

Population by Race

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%

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