Population
36,774
2025
+2.5% since 2020
Source: U.S. Census Bureau, Population Estimates Program (Vintage 2025), 2025. Resident population, July 1 estimate.
Sioux County had an estimated 36,774 residents in 2025, up 2.5% (886 more people) since 2020. That is faster than Iowa as a whole (+1.5%), and the 12th fastest growth of 99 counties in Iowa.
Data as of 2025 · updated
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36,774
2025
+2.5% since 2020
Source: U.S. Census Bureau, Population Estimates Program (Vintage 2025), 2025. Resident population, July 1 estimate.
−225
2025
−6.1 per 1,000 residents
−904 in total, 2021–2025
Source: U.S. Census Bureau, Population Estimates Program (Vintage 2025), 2025. People moving in from other U.S. counties minus people moving out.
2.3%
2025
+0.5 pts since 2019
Source: U.S. Bureau of Labor Statistics, Local Area Unemployment Statistics, 2025. Annual average unemployment rate.
359
2025
+206.8% since 2021
9.8 per 1,000 residents
Source: U.S. Census Bureau, Building Permits Survey, 2025. Housing units authorized by building permits in the year.
$86,098
2020–24
+17.5% since 2016–20
Source: U.S. Census Bureau, American Community Survey 5-year estimates, 2020–24. American Community Survey 5-year estimate.
20,910
2023
+12.3% since 2018
Source: U.S. Census Bureau, County Business Patterns, 2023. Paid employees of private employers in mid-March (County Business Patterns).
Net domestic migration was negative in 2025: 225 more people moved out to other U.S. counties than moved in.
Private employers had 20,910 paid employees in mid-March 2023, +12.3% since 2018 (County Business Patterns).
Unemployment averaged 2.3% in 2025, 0.5 points higher than in 2019 (before the pandemic).
Builders were authorized to start 359 new homes in 2025, or 9.8 per 1,000 residents.
Median household income was $86,098 in the 2020–24 American Community Survey, +17.5% since 2016–20.
Across the 3,107 U.S. counties with a comparable estimate, its population growth ranks 1,141st.
Email me when Sioux County gets new Census numbers: population, building permits, jobs and income. About 4 emails a year, one click to stop.
| Year | Population | Change |
|---|---|---|
| 2025 | 36,774 | −3 |
| 2024 | 36,777 | +283 |
| 2023 | 36,494 | +244 |
| 2022 | 36,250 | +279 |
| 2021 | 35,971 | +83 |
| 2020 | 35,888 | – |
Census Bureau population estimates, July 1 of each year.
Sioux County grew by 886 people since 2020 even though 904 more residents moved to other U.S. counties than came from them: births outnumbered deaths by 1,079, and net international migration added 720.
| Component | 2025 | 2020–25 | Share |
|---|---|---|---|
| Natural changebirths minus deaths | +191 | +1,079 | |
| International migrationfrom and to other countries | +30 | +720 | |
| Domestic migrationfrom and to other U.S. counties | −225 | −904 | |
| Census adjustmentbalancing residual | +1 | −9 | |
| Total change | −3 | +886 |
Census Bureau population estimates, components of change, each year July 1 to June 30. The components add up to the change in the estimate; the Census adjustment is the small balancing figure the Bureau publishes.
| Measure | In Iowa | Among U.S. counties |
|---|---|---|
| Population growth | 12th of 99 | 1,141st of 3,107 |
| Net domestic migration per 1,000 residents | 76th of 99 | 2,661st of 3,108 |
| Private-sector job growth | 11th of 99 | 511th of 3,092 |
| Median household income | 8th of 99 | 400th of 3,107 |
| Lowest unemployment rate | 2nd of 99 | 75th of 3,108 |
| New homes permitted per 1,000 residents | 3rd of 99 | 153rd of 3,005 |
1st = highest (lowest for unemployment). Counties are ranked only against others with a figure for the same period.
The County Growth and Demographics Report for Sioux County, IA as a PDF, from federal data: population and migration, housing and rents, permits, private employers and jobs, unemployment, ranks in the state and the country, and neighbouring counties, with a source next to every number. Pay once, no subscription.
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Over 2020–25, Sioux County's population change (+2.5%) was ahead of 4 of its 7 neighbouring counties and behind 3.
2 of its 7 neighbouring counties had a higher median household income than Sioux County's $86,098 (2020–24).
| County | Population2025 | Population change2020–25 | Net domestic migration per 1,000 residents2025 | Homes permitted per 1,000 residents2025 | Median household income2020–24 |
|---|---|---|---|---|---|
| Sioux County, IA This county | 36,774 | +2.5% | −6.1 | 9.8 | $86,098 |
| Lyon County, IA | 12,354 | +3.6% | −4.1 | 3.3 | $76,746 |
| Plymouth County, IA | 25,697 | +0.0% | 0.3 | 1.8 | $83,251 |
| O'Brien County, IA | 14,220 | +0.5% | 0.6 | 1.3 | $68,356 |
| Osceola County, IA | 5,980 | −3.6% | −2.7 | 0.5 | $69,239 |
| Lincoln County, SD | 77,145 | +17.5% | 20.3 | 3.0 | $99,166 |
| Union County, SD | 17,402 | +3.2% | −6.6 | 15.9 | $89,636 |
| Cherokee County, IA | 11,369 | −2.4% | −7.2 | 4.9 | $71,269 |
Census Bureau population estimates and building permits, American Community Survey 5-year income. Rates per 1,000 residents. – means no figure, or a base too small for a change or rate (it would swing on a few people). A figure from another period shows its year and is left out of the comparison.
Yes. Its population grew 2.5% between 2020 and 2025, about 886 more people (Census Bureau population estimates). Iowa as a whole changed +1.5% over the same years. That ranks 12th of 99 counties in Iowa for population growth.
On net, none in 2025: about 225 more people moved out to other U.S. counties than moved in (Census Bureau net domestic migration estimate).
It averaged 2.3% in 2025 (BLS Local Area Unemployment Statistics, annual average).
About 36,774 people, according to the U.S. Census Bureau's population estimate for July 1, 2025.
Private employers there had 20,910 paid employees in mid-March 2023, +12.3% since 2018 (Census Bureau County Business Patterns; government jobs and the self-employed are not counted).
Map, parcel and listing layers cover North and South Carolina only for now. This page and the other Iowa county pages carry the public federal growth figures.
Email me when Sioux County gets new Census numbers: population, building permits, jobs and income. About 4 emails a year, one click to stop.
Each number shows its own period. Changes compare the latest period with five years earlier (or the earliest period available). Beacon CRE last refreshed these figures on 2026-11-05. Figures come from public federal statistics and are informational only, not investment advice. Check the source before relying on a number. Methodology: how we compute every number. More on every layer: data sources and licences.
Jobs outside North and South Carolina use County Business Patterns (paid private-sector employees in mid-March); wages and government jobs are not included.