Clay County, South Dakota Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 14th-largest in South Dakota
The population of Clay County, South Dakota is 15,133 as of the 2023 American Community Survey, making it the 14th-largest county in South Dakota. The median household income is $58,794, the median home value is $221,800, and the median age is 24.5.
The population of Clay County has grown 10.2% since 2010 (13,830 → 15,245), a +0.70% annualized rate.
15,133
Population
+0.70%
Annual growth
37
People / sq mi
$58,794
Median Income
$221,800
Median Home Value
Clay County covers 412 sq mi of land at 36.7 people per square mile.
About Clay County, SD
Clay County skews on age — the median resident is 24.5, younger than the national median. With 15,133 residents, Clay County is a county in South Dakota. It ranks #14 among counties in South Dakota by population.
Median household income is $58,794, below the US median of $78,538. Only 4.8% of residents live in poverty, below the national 12.4%. Homes carry a median value of $221,800, with typical rent around $736.
Degree attainment is near the top of the range for US counties: 46.0% of adults 25+ hold a bachelor’s, above the 35.0% national rate. Remote work is below the national 14.0% at 7.7%, and the average commute runs about 18 minutes each way.
Clay County Population History (2010-2024)
The county of Clay County had a population of 13,830 in 2010 and 15,245 in 2024, a 10.2% growth over 14 years. The peak was 15,398 in 2023. Average annual growth rate: 0.71%.
15,245
Population (2024)
13,830
Population (2010)
15,398
Peak (2023)
0.71%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 13,830 |
| 2011 | 13,993 |
| 2012 | 14,077 |
| 2013 | 13,914 |
| 2014 | 13,907 |
| 2015 | 13,798 |
| 2016 | 13,980 |
| 2017 | 14,075 |
| 2018 | 13,985 |
| 2019 | 14,096 |
| 2020 | 15,003 |
| 2021 | 15,170 |
| 2022 | 15,277 |
| 2023 | 15,398 |
| 2024 | 15,245 |
Race & Ethnicity
| White | 86.7% |
| Black or African American | 2.0% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 6.0% |
| Two or More Races | 0.0% |
Age & Sex
24.5
Median Age
50.5%
Female
49.5%
Male
12.2%
Age 65+
Age Distribution
Children (under 15): 14.8% · Seniors (65+): 12.2%
Income & Poverty
| Median household income | $58,794$-13,627 vs state |
| Mean household income | $76,464 |
| Per-capita income | $29,412 |
| Poverty rate | 4.8%-2.6% vs state |
| Unemployment rate | 5.6% |
| Employment-to-population | 61.0% |
Top Industries by Employment
The largest employment sector in Clay County is professional & business services, accounting for 35.6% of workers.
How residents commute
0.3%
Drive alone
10.7%
Carpool
73.5%
Public transit
7.7%
Work from home
17.7 min
Avg commute
Housing
$221,800$-15,000 vs state
Median home value
$736
Median rent
51.8%
Homeownership rate
6,243
Total housing units
89.1%
Occupied
10.9%
Vacant
48.2%
Renter-occupied
Social & access
90.7%
With health insurance
94.5%
With broadband internet
40.9%
Foreign-born
4.6%
Veterans (18+)
11.7%
With a disability
94.4%
Speak language other than English at home
Education
93.9%
High School+
46.0%
Bachelor's+
Largest cities in South Dakota
Other counties in South Dakota
Part of South Dakota
Metro areas in South Dakota
County rankings
Frequently Asked Questions
Clay County, South Dakota has a population of 15,133 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 14th-largest county in South Dakota. Population density is 37 people per square mile.
The population of Clay County has grown 10.2% since 2010 (13,830 → 15,245), a +0.70% annualized rate.
The median household income in Clay County, South Dakota is $58,794, with mean (average) household income of $76,464 and per-capita income of $29,412. 4.8% of residents live below the federal poverty level.
In Clay County, the largest racial and ethnic groups are White (86.7%), Hispanic or Latino (6.0%), Black or African American (2.0%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in Clay County, South Dakota is 24.5 years. Residents are 50.5% female and 49.5% male.
The median home value in Clay County is $221,800 and median monthly rent is $736. 51.8% of occupied housing units are owner-occupied. The county has 6,243 total housing units, 10.9% of which are vacant.
The largest employment sector in Clay County, South Dakota is professional, scientific, and management services, employing 35.6% of workers. The unemployment rate is 5.6%.
Sioux Falls is among the largest cities associated with Clay County, South Dakota, with a population of 197,642.
Clay County, SD Climate
Clay County, SD has an average annual temperature of 8.6°C (47°F) and receives about 632 mm of precipitation per year. The warmest month is July and the coldest is January. Figures are 1970–2000 climate normals.
8.6°C
Avg Temp
632
Precip (mm/yr)
Jul
Hottest Month
Jan
Coldest Month
| Month | Avg (°C/°F) | Precip |
|---|---|---|
| January | -8° / 17° | 10 mm |
| February | -5° / 24° | 15 mm |
| March | 2° / 35° | 44 mm |
| April | 9° / 49° | 64 mm |
| May | 16° / 60° | 90 mm |
| June | 21° / 70° | 94 mm |
| July | 24° / 74° | 81 mm |
| August | 22° / 72° | 73 mm |
| September | 17° / 63° | 65 mm |
| October | 10° / 50° | 48 mm |
| November | 1° / 34° | 33 mm |
| December | -6° / 21° | 15 mm |
1970–2000 normals from WorldClim 2.1 (~9 km grid). Precipitation can be less precise near mountains or coastlines, where rainfall varies sharply over short distances.
Best time to visit Clay County, SD
The most comfortable months to visit Clay County, SD are typically August, June and July, when temperatures are mildest and rainfall is relatively low. The hottest month is July (around 31°C high). The coldest is January (near -14°C low). June is usually the wettest month.
Where to stay near Clay County
Visiting or relocating to Clay County, SD? Compare hotels and short-term rentals across the county — live availability and prices.
Top-rated places to stay near Clay County
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a move to Clay County?
Get relocation and cost-of-living insights for Clay County, SD by email. No spam, unsubscribe anytime.
More from South Dakota
Population 200,689
Population 112,081
Population 68,286
Population 38,079
Full rankings of South Dakota counties
Statewide data for South Dakota
Population, race, income, age, and trends across South Dakota
Data from the American Community Survey (ACS) 5-Year estimates.
Source: U.S. Census Bureau ACS, 2026.