Jefferson is a city located in Union County, South Dakota. Jefferson has a 2025 population of 443 . Jefferson is currently declining at a rate of -1.34% annually and its population has decreased by -6.34% 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. For every 100 females there are 114.7 males.
Data after 2023 is projected based on recent change
The racial composition of Jefferson includes 90.24% White, 4.18% Native American, and smaller percentages for other race and multiracial populations.
White (90.24%)
Native American (4.18%)
Two or more races (3.21%)
Other race (2.37%)
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% |
Married
Widowed
Divorced
Separated
Never Married
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%.
Name | Median | Mean |
|---|---|---|
| Married Families | $85,750 | - |
| Families | $81,554 | $84,363 |
| Households | $81,149 | $78,129 |
| Non Families | $50,000 | $62,464 |
Average Income
Median Household Income
Poverty Rate