Union County, South Dakota Demographics
Population trends, housing costs, income, commuting, and health, all on one page.
Union County, SD Population Density Map and Area Scores
Area Score
Health, income and education, each graded from F to A+. Explore interactive maps for deeper analysis.
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B
Health Around averageHealthier than 72% of counties in South Dakota
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B
Income Around averageAmong the top 3 wealthiest counties in South Dakota
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B
Education Around averageBetter educated than 91% of counties in South Dakota
Source: Map AI Methodology
Population: density and quick facts
| Metric | Union County | South Dakota Avg | U.S. Average |
|---|---|---|---|
| Population | 17,081 | 907,403 | 337,468,954 |
| Population density (per sq mi) | 36.6 | 11.8 | 86.4 |
| Population growth (%/yr) | 1.78% | 0.80% | 0.59% |
| Median age | 41.4 | 35.5 | 37.3 |
| Households | 7,310 | 365,533 | 130,235,071 |
Population in Union County grew by 22.5% from 2009 to 2024, reaching 17,081 in 2024.
Population Growth 2009–2024
Race & Ethnicity
Age & Sex
The largest generation in Union County is Millennials, aged 29–44, at 21.3% of residents. That is 0.8 points above South Dakota as a whole.
- Gen Z 13–28 3,212 18.8% -3.1 pts
- Millennials 29–44 3,636 21.3% +0.8 pts
- Gen X 45–60 3,506 20.5% +2.0 pts
- Boomers 61–79 3,041 17.8% +0.5 pts
Residents by birth cohort, from the 2025 age distribution. The right-hand figure is how far each cohort's share sits above or below South Dakota, in percentage points. Children younger than Gen Z and the generations before the Boomers are counted in the population but not shown here, so these shares do not add up to 100%.
Male and female share
Women are 49.5% of the people living in Union County and men 50.5%.
- Women 49.5% South Dakota 49.6%
- Men 50.5% South Dakota 50.4%
How many residents match a customer profile?
Residents matching this profile
100% of everyone living in Union County
Pick an age range and a women/men split and the figure above answers with how many residents that profile reaches.
Economy
Union County has a the economy index of B, which means it is quite prosperous.
| Metric | Union County | South Dakota Avg | U.S. Average |
|---|---|---|---|
| Median household income | $89,958 | $75,087 | $80,455 |
| Income growth (%/yr) | 4.34% | 4.61% | 4.80% |
| Unemployment rate | 2.9% | 2.9% | 5.2% |
The median household income in Union County is about 20% higher than in South Dakota.
Housing
| Metric | Union County | South Dakota Avg | U.S. Average |
|---|---|---|---|
| Median home price | $187,500 | $92,142 | $248,835 |
| Median rent | $1,069 | $946 | $1,407 |
| Homeownership rate | 73.1% | 68.6% | 65.2% |
The median home price in Union County is about 14.6 years' worth of rent — buying at the median price costs roughly as much as paying the median rent of $1,069 per month for that long.
Commute Time & Mobility
Commuters in Union County spend about 33 minutes on the road round trip each working day. Over a typical 250-day work year, that adds up to roughly 137 hours, about 5.7 full days, spent commuting.
| Metric | Union County | South Dakota Avg | U.S. Average |
|---|---|---|---|
| One-way commute (min) | 16.4 | 15.3 | 22.4 |
| Round-trip commute (min) | 32.8 | 30.7 | 44.8 |
| Yearly time spent (hours) | 137 | 128 | 187 |
| Estimated yearly cost | $4,238 | $3,961 | $5,790 |
| Work from home | 7.9% | 9.7% | 15.0% |
| Highway traffic (vehicles/day) | 4,126 | 2,777 | 8,813 |
| Local road traffic (vehicles/day) | 643 | 353 | 1,355 |
Fastest commutes among counties in
South Dakota:
Jones County (6.7 min), Bennett County (7.5 min), Jackson County (7.8 min).
Slowest:
Custer County (25.5 min), McCook County (25.4 min), Turner County (23.1 min).
The average commute time in Union County is 16 minutes, longer than the 15 minutes in South Dakota.
Estimated yearly cost applies a single national wage rule of thumb (U.S. Bureau of Labor Statistics average hourly earnings), not a measurement of wages in this area. Traffic volume figures come from proprietary Ticon and TrafficZoom data.
Education & Households
Union County has a education index of B, which means it is quite educated.
| Metric | Union County | South Dakota Avg | U.S. Average |
|---|---|---|---|
| Bachelor's degree or higher | 34.9% | 28.0% | 31.6% |
| Average household size | 2.32 | 2.40 | 2.53 |
Highest education index among counties in
South Dakota:
Clay County (0.4), Lincoln County (0.3), Stanley County (0.3).
Lowest:
Buffalo County (0.1), Mellette County (0.2), Oglala Lakota County (0.2).
Health
Union County has a health index of B, which means it is quite healthy.
| Metric | Union County | South Dakota Avg | U.S. Average |
|---|---|---|---|
| Life expectancy (years) | 80.7 | 79.9 | 78.3 |
| Self-rated poor health | 10.5% | 13.8% | 16.3% |
| Smokers | 16.6% | 19.9% | 19.0% |
Highest health index among counties in
South Dakota:
Brookings County (0.8), Lincoln County (0.8), Clay County (0.8).
Lowest:
Todd County (0.7), Buffalo County (0.7), Mellette County (0.7).
Union County, SD Compared With Nearby Counties
Union County, SD is the smallest of the 4 counties compared here, 17,081 residents against a local median of 25,747. Where Union County, SD breaks from the counties next to it is median home price, sitting more than 6 times the local median of $28,068 at $187,500.
The counties themselves spread $329,945 on median home price, so Union County, SD sits at one end of an already wide local range rather than apart from it. Union County, SD has the 2nd highest median home price of the 4 areas compared here.
| Area | Population | Median household income | Median home price | Commute |
|---|---|---|---|---|
| Union County, SD | 17,081 | $89,958 #2/4 | $187,500 #2/4 | 16.4 min #3/4 |
| Dakota County, NE | 21,354 | $70,667 | $7,777 | 13.1 min |
| Lincoln County, SD | 70,639 | $98,826 | $337,722 | 18.1 min |
| Plymouth County, IA | 25,747 | $83,321 | $28,068 | 16.0 min |
Frequently Asked Questions
Common questions about Union County, South Dakota.
How big is Union County, South Dakota by population?
About 17,081 people live in Union County, South Dakota, in 7,310 households of 2.3 people on average. The median age is 41.4, so residents are older than the U.S. median of 37.3 by about 4 years.
How densely populated is Union County, South Dakota?
Averaged over its land area, Union County, South Dakota has 37 people per square mile, a density typical of rural areas. That is about 42% of the U.S. average of 86.
Can a typical household afford a home in Union County, South Dakota?
The median home costs 2.1 times the median household income ($187,500 against $89,958), compared with 3.1 times nationally. That is within the traditional rule of thumb of about 3 times income. Median rent of $1,069 a month takes about 14% of the median household's income, below the 30% level at which HUD considers renters cost-burdened.
How strong is the job market in Union County, South Dakota?
Unemployment in Union County, South Dakota is only 2.9%, well below the U.S. rate of 5.2%, a sign of a tight labor market where employers compete for workers.
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