Fastest-growing counties in Iowa

·Stacker

Henryk Sadura // Shutterstock
Henryk Sadura // Shutterstock

Why do people move from one county or region to another? The usual suspects are jobs, family, significant others, and overall cost of living, but there are other elements at play. For those with children, moving within close proximity of a highly rated school district is a key contributing factor. For younger adults just starting out, living someplace with a vibrant social scene might be a top priority. And for those whose careers have wound down after a lifetime of work, finding retirement-friendly communities is the goal—communities deemed to be safe, offer accessibility to medical resources and leisure activities in equal measure, and be affordable for those on a limited income.

This is, of course, by no means an exhaustive list. People's reasons for choosing to live where they do are as diverse as people themselves.

As far as why certain counties across the U.S. have experienced growth, relocation is not the sole, or even primary, reason why. While more than 1,800 counties saw population gains in 2021, approximately 73% of all U.S. counties saw what the U.S. Census Bureau characterizes as a natural decrease. This was a significant jump from 2020, when 55.5% of countries experienced such a decrease. According to the Bureau, natural decrease is the simple result of "when there are more deaths than births in a population over a given time period." In 2021, the conflation of fewer births with an aging population that was also absorbing a higher-than-usual mortality rate due to the ongoing COVID-19 pandemic led to this "increased decrease."

Nonetheless, as stated 1,800 counties nationwide have grown larger over the last year, and a sizable percentage of them are in Iowa. Stacker compiled a list of the fastest-growing counties in Iowa using data from the U.S. Census Bureau. Counties are ranked by the highest population growth from 2010 to 2020, based on the U.S. Decennial Census.

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#50. Clay County

- 2010 to 2020 population change: -283
--- #1,889 among all counties nationwide
- 2010 to 2020 percent population change: -1.7%
--- #42 among counties in Iowa, #1,785 among all counties nationwide
- 2020 population: 16,384
--- #47 largest county in Iowa, #2,010 largest county nationwide
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#49. Delaware County

- 2010 to 2020 population change: -276
--- #1,875 among all counties nationwide
- 2010 to 2020 percent population change: -1.6%
--- #41 among counties in Iowa, #1,754 among all counties nationwide
- 2020 population: 17,488
--- #40 largest county in Iowa, #1,942 largest county nationwide
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#48. Osceola County

- 2010 to 2020 population change: -270
--- #1,865 among all counties nationwide
- 2010 to 2020 percent population change: -4.2%
--- #72 among counties in Iowa, #2,193 among all counties nationwide
- 2020 population: 6,192
--- #95 largest county in Iowa, #2,721 largest county nationwide
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#47. Allamakee County

- 2010 to 2020 population change: -269
--- #1,863 among all counties nationwide
- 2010 to 2020 percent population change: -1.9%
--- #46 among counties in Iowa, #1,819 among all counties nationwide
- 2020 population: 14,061
--- #57 largest county in Iowa, #2,151 largest county nationwide
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#46. Lucas County

- 2010 to 2020 population change: -264
--- #1,858 among all counties nationwide
- 2010 to 2020 percent population change: -3.0%
--- #56 among counties in Iowa, #1,993 among all counties nationwide
- 2020 population: 8,634
--- #85 largest county in Iowa, #2,518 largest county nationwide

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#45. Poweshiek County

- 2010 to 2020 population change: -252
--- #1,843 among all counties nationwide
- 2010 to 2020 percent population change: -1.3%
--- #38 among counties in Iowa, #1,712 among all counties nationwide
- 2020 population: 18,662
--- #37 largest county in Iowa, #1,887 largest county nationwide
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#44. Pocahontas County

- 2010 to 2020 population change: -232
--- #1,821 among all counties nationwide
- 2010 to 2020 percent population change: -3.2%
--- #59 among counties in Iowa, #2,027 among all counties nationwide
- 2020 population: 7,078
--- #91 largest county in Iowa, #2,650 largest county nationwide
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#43. Humboldt County

- 2010 to 2020 population change: -218
--- #1,801 among all counties nationwide
- 2010 to 2020 percent population change: -2.2%
--- #51 among counties in Iowa, #1,884 among all counties nationwide
- 2020 population: 9,597
--- #78 largest county in Iowa, #2,444 largest county nationwide
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#42. O'Brien County

- 2010 to 2020 population change: -216
--- #1,797 among all counties nationwide
- 2010 to 2020 percent population change: -1.5%
--- #40 among counties in Iowa, #1,744 among all counties nationwide
- 2020 population: 14,182
--- #56 largest county in Iowa, #2,138 largest county nationwide
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#41. Mitchell County

- 2010 to 2020 population change: -211
--- #1,790 among all counties nationwide
- 2010 to 2020 percent population change: -2.0%
--- #48 among counties in Iowa, #1,838 among all counties nationwide
- 2020 population: 10,565
--- #71 largest county in Iowa, #2,373 largest county nationwide

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#40. Mahaska County

- 2010 to 2020 population change: -191
--- #1,756 among all counties nationwide
- 2010 to 2020 percent population change: -0.9%
--- #34 among counties in Iowa, #1,625 among all counties nationwide
- 2020 population: 22,190
--- #28 largest county in Iowa, #1,705 largest county nationwide
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#39. Wapello County

- 2010 to 2020 population change: -188
--- #1,751 among all counties nationwide
- 2010 to 2020 percent population change: -0.5%
--- #33 among counties in Iowa, #1,576 among all counties nationwide
- 2020 population: 35,437
--- #20 largest county in Iowa, #1,294 largest county nationwide
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#38. Winnebago County

- 2010 to 2020 population change: -187
--- #1,749 among all counties nationwide
- 2010 to 2020 percent population change: -1.7%
--- #43 among counties in Iowa, #1,795 among all counties nationwide
- 2020 population: 10,679
--- #69 largest county in Iowa, #2,365 largest county nationwide
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#37. Adair County

- 2010 to 2020 population change: -186
--- #1,747 among all counties nationwide
- 2010 to 2020 percent population change: -2.4%
--- #54 among counties in Iowa, #1,915 among all counties nationwide
- 2020 population: 7,496
--- #88 largest county in Iowa, #2,619 largest county nationwide
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#36. Worth County

- 2010 to 2020 population change: -155
--- #1,711 among all counties nationwide
- 2010 to 2020 percent population change: -2.0%
--- #49 among counties in Iowa, #1,862 among all counties nationwide
- 2020 population: 7,443
--- #89 largest county in Iowa, #2,625 largest county nationwide

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#35. Grundy County

- 2010 to 2020 population change: -124
--- #1,658 among all counties nationwide
- 2010 to 2020 percent population change: -1.0%
--- #35 among counties in Iowa, #1,653 among all counties nationwide
- 2020 population: 12,329
--- #60 largest county in Iowa, #2,254 largest county nationwide
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#34. Howard County

- 2010 to 2020 population change: -97
--- #1,628 among all counties nationwide
- 2010 to 2020 percent population change: -1.0%
--- #36 among counties in Iowa, #1,655 among all counties nationwide
- 2020 population: 9,469
--- #79 largest county in Iowa, #2,455 largest county nationwide
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#33. Ida County

- 2010 to 2020 population change: -84
--- #1,607 among all counties nationwide
- 2010 to 2020 percent population change: -1.2%
--- #37 among counties in Iowa, #1,686 among all counties nationwide
- 2020 population: 7,005
--- #92 largest county in Iowa, #2,658 largest county nationwide
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#32. Carroll County

- 2010 to 2020 population change: -56
--- #1,571 among all counties nationwide
- 2010 to 2020 percent population change: -0.3%
--- #32 among counties in Iowa, #1,536 among all counties nationwide
- 2020 population: 20,760
--- #30 largest county in Iowa, #1,774 largest county nationwide
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#31. Cedar County

- 2010 to 2020 population change: +6
--- #1,482 among all counties nationwide
- 2010 to 2020 percent population change: +0.0%
--- #31 among counties in Iowa, #1,487 among all counties nationwide
- 2020 population: 18,505
--- #38 largest county in Iowa, #1,894 largest county nationwide

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#30. Jones County

- 2010 to 2020 population change: +8
--- #1,478 among all counties nationwide
- 2010 to 2020 percent population change: +0.0%
--- #30 among counties in Iowa, #1,484 among all counties nationwide
- 2020 population: 20,646
--- #31 largest county in Iowa, #1,778 largest county nationwide
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#29. Black Hawk County

- 2010 to 2020 population change: +54
--- #1,427 among all counties nationwide
- 2010 to 2020 percent population change: +0.0%
--- #29 among counties in Iowa, #1,482 among all counties nationwide
- 2020 population: 131,144
--- #5 largest county in Iowa, #492 largest county nationwide
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#28. Wayne County

- 2010 to 2020 population change: +94
--- #1,400 among all counties nationwide
- 2010 to 2020 percent population change: +1.5%
--- #25 among counties in Iowa, #1,257 among all counties nationwide
- 2020 population: 6,497
--- #94 largest county in Iowa, #2,698 largest county nationwide
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#27. Marion County

- 2010 to 2020 population change: +105
--- #1,388 among all counties nationwide
- 2010 to 2020 percent population change: +0.3%
--- #28 among counties in Iowa, #1,443 among all counties nationwide
- 2020 population: 33,414
--- #22 largest county in Iowa, #1,345 largest county nationwide
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#26. Calhoun County

- 2010 to 2020 population change: +257
--- #1,291 among all counties nationwide
- 2010 to 2020 percent population change: +2.7%
--- #20 among counties in Iowa, #1,098 among all counties nationwide
- 2020 population: 9,927
--- #75 largest county in Iowa, #2,414 largest county nationwide

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#25. Iowa County

- 2010 to 2020 population change: +307
--- #1,256 among all counties nationwide
- 2010 to 2020 percent population change: +1.9%
--- #22 among counties in Iowa, #1,204 among all counties nationwide
- 2020 population: 16,662
--- #44 largest county in Iowa, #1,994 largest county nationwide
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#24. Henry County

- 2010 to 2020 population change: +337
--- #1,236 among all counties nationwide
- 2010 to 2020 percent population change: +1.7%
--- #23 among counties in Iowa, #1,234 among all counties nationwide
- 2020 population: 20,482
--- #33 largest county in Iowa, #1,789 largest county nationwide
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#23. Lyon County

- 2010 to 2020 population change: +353
--- #1,229 among all counties nationwide
- 2010 to 2020 percent population change: +3.0%
--- #16 among counties in Iowa, #1,052 among all counties nationwide
- 2020 population: 11,934
--- #64 largest county in Iowa, #2,287 largest county nationwide
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#22. Davis County

- 2010 to 2020 population change: +357
--- #1,228 among all counties nationwide
- 2010 to 2020 percent population change: +4.1%
--- #13 among counties in Iowa, #919 among all counties nationwide
- 2020 population: 9,110
--- #81 largest county in Iowa, #2,481 largest county nationwide
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#21. Boone County

- 2010 to 2020 population change: +409
--- #1,200 among all counties nationwide
- 2010 to 2020 percent population change: +1.6%
--- #24 among counties in Iowa, #1,246 among all counties nationwide
- 2020 population: 26,715
--- #23 largest county in Iowa, #1,539 largest county nationwide

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#20. Clarke County

- 2010 to 2020 population change: +462
--- #1,163 among all counties nationwide
- 2010 to 2020 percent population change: +5.0%
--- #12 among counties in Iowa, #823 among all counties nationwide
- 2020 population: 9,748
--- #77 largest county in Iowa, #2,433 largest county nationwide
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#19. Muscatine County

- 2010 to 2020 population change: +490
--- #1,152 among all counties nationwide
- 2010 to 2020 percent population change: +1.1%
--- #26 among counties in Iowa, #1,316 among all counties nationwide
- 2020 population: 43,235
--- #13 largest county in Iowa, #1,111 largest county nationwide
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#18. Pottawattamie County

- 2010 to 2020 population change: +509
--- #1,147 among all counties nationwide
- 2010 to 2020 percent population change: +0.5%
--- #27 among counties in Iowa, #1,404 among all counties nationwide
- 2020 population: 93,667
--- #10 largest county in Iowa, #639 largest county nationwide
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#17. Buena Vista County

- 2010 to 2020 population change: +563
--- #1,128 among all counties nationwide
- 2010 to 2020 percent population change: +2.8%
--- #19 among counties in Iowa, #1,086 among all counties nationwide
- 2020 population: 20,823
--- #29 largest county in Iowa, #1,770 largest county nationwide
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#16. Bremer County

- 2010 to 2020 population change: +712
--- #1,087 among all counties nationwide
- 2010 to 2020 percent population change: +2.9%
--- #17 among counties in Iowa, #1,065 among all counties nationwide
- 2020 population: 24,988
--- #26 largest county in Iowa, #1,602 largest county nationwide

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#15. Plymouth County

- 2010 to 2020 population change: +712
--- #1,087 among all counties nationwide
- 2010 to 2020 percent population change: +2.8%
--- #18 among counties in Iowa, #1,076 among all counties nationwide
- 2020 population: 25,698
--- #24 largest county in Iowa, #1,572 largest county nationwide
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#14. Washington County

- 2010 to 2020 population change: +861
--- #1,041 among all counties nationwide
- 2010 to 2020 percent population change: +4.0%
--- #14 among counties in Iowa, #929 among all counties nationwide
- 2020 population: 22,565
--- #27 largest county in Iowa, #1,692 largest county nationwide
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#13. Madison County

- 2010 to 2020 population change: +869
--- #1,038 among all counties nationwide
- 2010 to 2020 percent population change: +5.5%
--- #11 among counties in Iowa, #768 among all counties nationwide
- 2020 population: 16,548
--- #45 largest county in Iowa, #2,000 largest county nationwide
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#12. Jasper County

- 2010 to 2020 population change: +971
--- #1,007 among all counties nationwide
- 2010 to 2020 percent population change: +2.6%
--- #21 among counties in Iowa, #1,103 among all counties nationwide
- 2020 population: 37,813
--- #17 largest county in Iowa, #1,227 largest county nationwide
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#11. Dickinson County

- 2010 to 2020 population change: +1,036
--- #992 among all counties nationwide
- 2010 to 2020 percent population change: +6.2%
--- #8 among counties in Iowa, #684 among all counties nationwide
- 2020 population: 17,703
--- #39 largest county in Iowa, #1,935 largest county nationwide

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#10. Sioux County

- 2010 to 2020 population change: +2,168
--- #795 among all counties nationwide
- 2010 to 2020 percent population change: +6.4%
--- #7 among counties in Iowa, #670 among all counties nationwide
- 2020 population: 35,872
--- #19 largest county in Iowa, #1,286 largest county nationwide
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#9. Woodbury County

- 2010 to 2020 population change: +3,769
--- #640 among all counties nationwide
- 2010 to 2020 percent population change: +3.7%
--- #15 among counties in Iowa, #966 among all counties nationwide
- 2020 population: 105,941
--- #6 largest county in Iowa, #578 largest county nationwide
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#8. Dubuque County

- 2010 to 2020 population change: +5,613
--- #547 among all counties nationwide
- 2010 to 2020 percent population change: +6.0%
--- #9 among counties in Iowa, #717 among all counties nationwide
- 2020 population: 99,266
--- #8 largest county in Iowa, #612 largest county nationwide
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#7. Warren County

- 2010 to 2020 population change: +6,178
--- #531 among all counties nationwide
- 2010 to 2020 percent population change: +13.4%
--- #4 among counties in Iowa, #270 among all counties nationwide
- 2020 population: 52,403
--- #11 largest county in Iowa, #963 largest county nationwide
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#6. Story County

- 2010 to 2020 population change: +8,995
--- #450 among all counties nationwide
- 2010 to 2020 percent population change: +10.0%
--- #5 among counties in Iowa, #415 among all counties nationwide
- 2020 population: 98,537
--- #9 largest county in Iowa, #616 largest county nationwide

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#5. Scott County

- 2010 to 2020 population change: +9,445
--- #443 among all counties nationwide
- 2010 to 2020 percent population change: +5.7%
--- #10 among counties in Iowa, #748 among all counties nationwide
- 2020 population: 174,669
--- #3 largest county in Iowa, #380 largest county nationwide
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#4. Linn County

- 2010 to 2020 population change: +19,073
--- #301 among all counties nationwide
- 2010 to 2020 percent population change: +9.0%
--- #6 among counties in Iowa, #482 among all counties nationwide
- 2020 population: 230,299
--- #2 largest county in Iowa, #298 largest county nationwide
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#3. Johnson County

- 2010 to 2020 population change: +21,972
--- #269 among all counties nationwide
- 2010 to 2020 percent population change: +16.8%
--- #2 among counties in Iowa, #171 among all counties nationwide
- 2020 population: 152,854
--- #4 largest county in Iowa, #444 largest county nationwide
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#2. Dallas County

- 2010 to 2020 population change: +33,543
--- #187 among all counties nationwide
- 2010 to 2020 percent population change: +50.7%
--- #1 among counties in Iowa, #4 among all counties nationwide
- 2020 population: 99,678
--- #7 largest county in Iowa, #608 largest county nationwide
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#1. Polk County

- 2010 to 2020 population change: +61,761
--- #103 among all counties nationwide
- 2010 to 2020 percent population change: +14.3%
--- #3 among counties in Iowa, #246 among all counties nationwide
- 2020 population: 492,401
--- #1 largest county in Iowa, #146 largest county nationwide

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