Marshall County, Iowa Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 15th-largest in Iowa
The population of Marshall County, Iowa is 39,971 as of the 2023 American Community Survey, making it the 15th-largest county in Iowa. The median household income is $72,785, the median home value is $134,100, and the median age is 38.7.
The population of Marshall County has declined 0.8% since 2010 (40,722 → 40,392), a -0.06% annualized rate.
39,971
Population
-0.06%
Annual growth
70
People / sq mi
$72,785
Median Income
$134,100
Median Home Value
Marshall County covers 573 sq mi of land at 69.8 people per square mile.
About Marshall County, IA
Marshall County skews on age — the median resident is 38.7, in line with the national median. Marshall County is a county in Iowa with a population of 39,971. It ranks #15 among counties in Iowa by population.
Households take in a median $72,785, comfortably below the US median of $78,538. Poverty runs at 7.7%, below the national 12.4%. Property is affordable here, the median home worth $134,100, with typical rent around $860.
Roughly 21.4% of adults have a bachelor’s, below the national 35.0%. About 7.0% of the workforce is home-based, below the national 14.0%, and the average commute runs about 20 minutes each way.
Marshall County Population History (2010-2024)
The county of Marshall County had a population of 40,722 in 2010 and 40,392 in 2024, a -0.8% growth over 14 years. The peak was 41,032 in 2012. Average annual growth rate: -0.06%.
40,392
Population (2024)
40,722
Population (2010)
41,032
Peak (2012)
-0.06%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 40,722 |
| 2011 | 41,013 |
| 2012 | 41,032 |
| 2013 | 40,993 |
| 2014 | 40,712 |
| 2015 | 40,340 |
| 2016 | 40,122 |
| 2017 | 40,051 |
| 2018 | 39,879 |
| 2019 | 39,472 |
| 2020 | 40,091 |
| 2021 | 39,915 |
| 2022 | 39,940 |
| 2023 | 40,230 |
| 2024 | 40,392 |
Race & Ethnicity
| White | 74.6% |
| Black or African American | 1.9% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 1.9% |
| Two or More Races | 0.0% |
Age & Sex
38.7
Median Age
49.2%
Female
50.8%
Male
18.4%
Age 65+
Age Distribution
Children (under 15): 20.7% · Seniors (65+): 18.4%
Income & Poverty
| Median household income | $72,785$-362 vs state |
| Mean household income | $84,571 |
| Per-capita income | $32,737 |
| Poverty rate | 7.7%+0.8% vs state |
| Unemployment rate | 2.7% |
| Employment-to-population | 63.9% |
Top Industries by Employment
The largest employment sector in Marshall County is manufacturing, accounting for 23.7% of workers.
How residents commute
0.0%
Drive alone
2.9%
Carpool
76.4%
Public transit
7.0%
Work from home
20.1 min
Avg commute
Housing
$134,100$-61,800 vs state
Median home value
$860
Median rent
73.3%
Homeownership rate
16,860
Total housing units
92.2%
Occupied
7.8%
Vacant
26.7%
Renter-occupied
Social & access
94.6%
With health insurance
92.8%
With broadband internet
18.0%
Foreign-born
8.9%
Veterans (18+)
12.2%
With a disability
76.2%
Speak language other than English at home
Education
87.0%
High School+
21.4%
Bachelor's+
Largest cities in Iowa
Other counties in Iowa
Part of Iowa
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County rankings
Frequently Asked Questions
Marshall County, Iowa has a population of 39,971 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 15th-largest county in Iowa. Population density is 70 people per square mile.
The population of Marshall County has declined 0.8% since 2010 (40,722 → 40,392), a -0.06% annualized rate.
The median household income in Marshall County, Iowa is $72,785, with mean (average) household income of $84,571 and per-capita income of $32,737. 7.7% of residents live below the federal poverty level.
In Marshall County, the largest racial and ethnic groups are White (74.6%), Black or African American (1.9%), Hispanic or Latino (1.9%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in Marshall County, Iowa is 38.7 years. Residents are 49.2% female and 50.8% male.
The median home value in Marshall County is $134,100 and median monthly rent is $860. 73.3% of occupied housing units are owner-occupied. The county has 16,860 total housing units, 7.8% of which are vacant.
The largest employment sector in Marshall County, Iowa is manufacturing, employing 23.7% of workers. The unemployment rate is 2.7%.
Des Moines is among the largest cities associated with Marshall County, Iowa, with a population of 212,464.
Marshall County, IA Climate
Marshall County, IA has an average annual temperature of 8.7°C (48°F) and receives about 863 mm of precipitation per year. The warmest month is July and the coldest is January. Figures are 1970–2000 climate normals.
8.7°C
Avg Temp
863
Precip (mm/yr)
Jul
Hottest Month
Jan
Coldest Month
| Month | Avg (°C/°F) | Precip |
|---|---|---|
| January | -8° / 17° | 23 mm |
| February | -5° / 24° | 27 mm |
| March | 2° / 36° | 56 mm |
| April | 9° / 49° | 82 mm |
| May | 16° / 60° | 104 mm |
| June | 21° / 70° | 119 mm |
| July | 23° / 74° | 105 mm |
| August | 22° / 71° | 112 mm |
| September | 17° / 63° | 93 mm |
| October | 11° / 51° | 66 mm |
| November | 2° / 36° | 45 mm |
| December | -5° / 22° | 31 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 Marshall County, IA
The most comfortable months to visit Marshall County, IA are typically June, August and July, when temperatures are mildest and rainfall is relatively low. The hottest month is July (around 29°C high). The coldest is January (near -13°C low). June is usually the wettest month.
Where to stay near Marshall County
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Data from the American Community Survey (ACS) 5-Year estimates.
Source: U.S. Census Bureau ACS, 2026.