Plymouth County, IA demographics:
population, income, and more

Total population
25,747
0.2% year-over-year change
Median household income
$83,251/yr
2.0% year-over-year change
Housing units
10,891
0.3% year-over-year change

Plymouth County population

How many people live in Plymouth County

Plymouth County is home to 25,747 residents, according to the most recent Census data. Gender-wise, 50.9% of Plymouth County locals are male, and 49.1% are female.

Total population
25,747
0.2% year-over-year change
Gender ratio
Male
50.9%
13,115
Female
49.1%
12,632
Value Percent YoY change
Male 13,115 50.9% 0.2%
Female 12,632 49.1% 0.2%
A higher population often means more rental variety and livelier areas. The gender balance—how many men live here compared to women—can reveal a lot about the community and the lifestyles of its residents. Use this info to get a sense of the area's pace and personality.

Age demographics

The median age in Plymouth County is 41, with the population distributed as follows: about 20.3% are children under 15, then 11.8% are in the 15 to 24 age group. Adults between 25 and 44 make up 23.1% of the population, while another 25.1% fall into the 45 to 64 bracket. Finally, around 19.8% are 65 or older.

Median age
41.3
Age breakdown
Under 15
20.3%
15 to 24
11.8%
25 to 44
23.1%
45 to 64
25.1%
Over 65
19.8%
Value Percent YoY change
Under 15 5,217 20.3% 1.2%
15 to 24 3,024 11.8% -2.1%
25 to 44 5,937 23.1% 0.4%
45 to 64 6,473 25.1% -1.7%
Over 65 5,096 19.8% 2.8%
The age composition helps you get insight into who lives in the area. A younger population might mean a more active, fast-paced vibe, while an older one could suggest a quieter, slower lifestyle. If there's a balanced makeup, you’re likely to find a variety of services, housing types, and community spaces that cater to different life stages.

Racial makeup

In Plymouth County, 95.5% of the population are US-born citizens, while 2.4% have gained naturalized citizenship. At the same time, 2.1% of residents are non-citizens. As for race, 89.4% of locals are Caucasian, 2.4% are African American and 0.5% have Asian roots. Another 0.4% are Indigenous American, 0.4% are Pacific Islanders, while 2.1% identify as another race. There’s also a share of 4.8% that includes residents with two or more races.

Citizenship
U.S.-born citizens
95.5%
Non-U.S.-born citizens
2.4%
Non-citizens
2.1%
Value Percent YoY change
U.S.-born citizens 24,597 95.5% 0.9%
Non-U.S.-born citizens 612 2.4% -10.5%
Non-citizens 538 2.1% -16.6%
Racial breakdown
White
89.4%
Black or African American
2.4%
American Indian and Alaska Native
0.4%
Asian
0.5%
Native Hawaiian and other Pacific Islander
0.4%
Two or more races
4.8%
Other
2.1%
Value Percent
White 23,022 89.4%
Black or African American 615 2.4%
American Indian and Alaska Native 110 0.4%
Asian 135 0.5%
Native Hawaiian and other Pacific Islander 112 0.4%
Two or more races 1,222 4.8%
Other 531 2.1%

Households in Plymouth County

A peek inside Plymouth County households

Plymouth County has 10,313 households, with an average of 2 members in each. Of these, 69.1% are families, while the remaining 30.9% are made up of individuals living alone or with non-relatives, such as roommates.

Households stats

Total households
10,313
0.2% year-over-year change
Average people per household
2
Non-family households
3,184
Family households
7,129
Value Percent YoY change
Non-family households 3,184 30.9% 0.4%
Family households 7,129 69.1% 0.1%
The mix between family and non-family households gives a glimpse into daily life. A higher percentage of families might mean more parks and schools, while more non-family setups can mean flexible housing and diverse living styles. For renters, this can signal what kinds of homes are common and can help you figure out if the area matches your lifestyle.

Housing in Plymouth County

The housing landscape of Plymouth County

Plymouth County's housing consists of 10,891 units, with 78.9% being detached single-family homes ideal for those wanting space. Attached options, including duplexes and townhouses, make up 3.3% and offer a more compact, shared living style. Then there are the multifamily buildings in the area, and for those seeking flexibility, non-traditional options like mobile homes account for 3.8% of the housing landscape.

Housing units
10,891
0.3% year-over-year change
Housing types
Value Percent
1 unit, detached 8,594 78.9%
1 unit, attached 361 3.3%
2 units 83 0.8%
3 or 4 units 535 4.9%
5 to 9 units 245 2.2%
10 to 19 units 475 4.4%
20 to 49 units 181 1.7%
50 or more units 6 0.1%
Mobile home 411 3.8%
Homes built since 2020
131
22.4% year-over-year change

The age of buildings in Plymouth County

In Plymouth County, the median construction year is 1971. About 24.5% of homes were built before the 1940s, with another 4.1% going up by 1949. Most development happened in the second half of the 20th century. Then, 8.6% of homes were added from 2000 to 2009, 6.6% between 2010 and 2019, and 1.2% are part of the newest wave of development.

Construction year breakdown by decade
Value Percent YoY change
Built in 1939 or earlier 2,665 24.5% -1.7%
Built between 1940 and 1949 445 4.1% 8.3%
Built between 1950 and 1959 1,177 10.8% 7.6%
Built between 1960 and 1969 943 8.7% 5.2%
Built between 1970 and 1979 1,604 14.7% -8.4%
Built between 1980 and 1989 942 8.6% 20.6%
Built between 1990 and 1999 1,332 12.2% -7.6%
Built between 2000 and 2009 937 8.6% 2.3%
Built between 2010 and 2019 715 6.6% -5.2%
Built in 2020 or later 131 1.2% 22.4%
As a renter, knowing when homes were built helps you understand the potential condition and design of rental units. Newer builds may have more contemporary layouts, while older homes can offer character or larger lots, depending on the area.

Plymouth County occupancy rates

Out of the 10,313 occupied housing units in Plymouth County, 73.6% are owner-occupied, while 26.4% are lived in by tenants. Meanwhile, 5.3% of all homes on the local market sit vacant.

Occupied housing units
10,313
0.2% year-over-year change
Occupancy breakdown
Renter occupied
2,722
Owner occupied
7,591
Value Percent YoY
change
Renter occupied 2,722 26.4% 0.4%
Owner occupied 7,591 73.6% 0.1%
Unoccupied housing units
5.3%
Unoccupied housing units refer to homes that are currently without residents—whether they're waiting for renters or owners, used seasonally, or simply unclaimed. A higher share of empty homes may mean more housing availability, while a low number can reflect a tighter market with more competition. This, along with the renter-vs.-owner mix, helps paint a clearer picture of what types of housing and services are likely to be available in the area.

Plymouth County housing costs

Housing costs in Plymouth County come to a median of $916 per month, while tenants specifically pay a median gross rent of $910.

Median housing costs per month
$916/month
This figure sums up typical monthly housing costs for all households in the area. If you own, it includes mortgage payments in addition to property taxes, insurance and HOA fees. If you rent, it accounts for rent plus extras like utilities. It’s useful for seeing how local living expenses stack up compared to other places.
Median gross rent in Plymouth County
$910/month
Gross rent gives a more complete look at what renters actually pay, including not just base rent, but also utilities and fees. It’s a key number for evaluating rental affordability in your area of interest and understanding how it compares to nearby locations.

Education in Plymouth County

Plymouth County education at a glance

About 40.5% of the population in Plymouth County went to high school, while 21.8% pursued college studies. Another 15% earned an associate degree and 16% hold a bachelor’s. Meanwhile, 4.5% went even further, earning a master’s or doctorate.

Education level
Value Percent YoY change
No high school 412 2.1% -9.4%
High school diploma 7,822 40.5% 1.6%
College diploma 4,207 21.8% 3.3%
Associate degree 2,890 15% 6.4%
Bachelor's degree 3,096 16% -8.3%
Graduate degree 877 4.5% -9.5%
A community’s education mix can offer insights into the local economy and housing market. Higher levels of education often align with more job opportunities and stable incomes, which can increase demand for homes and influence both rent prices and rental availability.

Income in Plymouth County

How much people earn in Plymouth County

The average annual household income in Plymouth County was $101,116 in 2024, the most recent annual data available, according to the U.S. Census Bureau. This marked a -2.1% change from the previous year. At the same time, the median income stood at $83,251, reflecting a +2% shift over the same period.

Average household income in Plymouth County
$101,116/year
-2.1% year-over-year change
Median household income in Plymouth County
$83,251/year
2.0% year-over-year change

Plymouth County income by age

In Plymouth County, households led by residents aged 25 to 44 — usually in the early to mid stages of their careers — have a median income of $92,702. Those with someone between 45 and 64 in charge, often well established professionally, earn $102,267 overall. Younger households, where the main provider is under 25 and just starting out, report a median income of $53,250, while those led by someone over 65, many of whom may be retired, have about $56,204 in earnings. Overall, 93.1% of the locals in this community live above the poverty line.

Income breakdown by age
Value YoY change
Under 25 $53,250 -1.3%
25 - 44 $92,702 3.2%
45 - 64 $102,267 7.8%
Over 65 $56,204 1.3%
Above poverty level
23,484
Below poverty level
1,735
Value Percent YoY
change
Above poverty level 23,484 93.1% 0.0%
Below poverty level 1,735 6.9% 1.8%

Employment in Plymouth County

Workforce and job types in Plymouth County

The job market in Plymouth County is powered by 13,519 working residents, spread across a range of industries and roles. 67.2% of the working population are employed in professional or administrative positions, while 32.8% are in hands-on or service-based jobs. Also, 13.7% run their own businesses, 64.3% are employed by private companies, and 11.9% work in the public sector.

Workforce demographics

Working population
13,519
-0.0% year-over-year change
White collar
9,090
Blue collar
4,429
Value Percent YoY change
White collar 9,090 67.2% 1.4%
Blue collar 4,429 32.8% -2.8%
Employer type
Self employees
13.7%
Private companies
64.3%
Governmental workers
11.9%
Not for profit companies
10.1%
Value Percent YoY change
Self employees 1,855 13.7% 4.4%
Private companies 8,696 64.3% 0.2%
Governmental workers 1,607 11.9% -3.8%
Not for profit companies 1,361 10.1% -2.2%
Unemployment rate
2.2%
18.8% year-over-year change

Available workforce

The unemployment rate in Plymouth County stands at 2.2%, representing the share of the workforce currently without a job and actively looking for one.

For renters, the unemployment rate helps paint a picture of job security and financial stability in the area. Rates around 4% to 5% are considered typical. A lower-than-average rate might suggest strong job prospects and a thriving local economy, while a higher rate could hint at fewer opportunities—both useful to consider when planning a move.

Transportation in Plymouth County

How people get around in Plymouth County

Commuting methods vary: 88.2% of residents travel by personal vehicle and 1.1% prefer to walk, while the remaining share relies on public transit or on two wheelers to get from A to B.

Means of transportation
Value Percent YoY change
Car 11,799 88.2% 0.0%
Bus or trolleybus 52 0.4% 15.6%
Railroad 22 0.2% 100.0%
Motorcycle 8 0.1% -11.1%
Bicycle 22 0.2% 83.3%
Walk 147 1.1% -50.7%
Understanding how locals get to work can help you plan your own routine. High car usage might mean you’ll need a vehicle, while strong public transit or walkability could save you the hassle. Commute times also play a big role in quality of life—shorter trips can give you more time for the things you enjoy.

What is the median and average household income in Plymouth County by zipcode?

Zipcode Population Number of households Median income Average income
51108 5,960 2,160 $81,205 $104,784
51001 2,342 1,041 $75,404 $90,658
51008 210 76 $45,000 $56,407
51024 2,081 819 $114,219 $121,897
51027 1,280 415 $100,893 $112,634
51028 2,191 904 $78,000 $100,107
51031 12,808 5,217 $76,525 $92,229
51038 1,449 553 $95,893 $100,639
51050 2,962 1,062 $92,500 $116,488
51062 503 240 $0 $92,657

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FAQs about Plymouth County demographics 

What is the total population of Plymouth County?

Plymouth County has a total population of 25,747 residents, according to the latest release from the U.S. Census Bureau: the 2019-2023 American Community Survey (ACS) 5-year estimates. This figure changed by +0.2% compared to a year ago.

What is the gender ratio in Plymouth County?

The gender ratio in Plymouth County is as follows:
  • 50.9% males (13,115 residents)
  • 49.1% females (12,632 residents)

What is the median age in Plymouth County?

The median age in Plymouth County is 41.3.

What is the age distribution of the population in Plymouth County?

The age distribution in Plymouth County is as follows:
  • Under 15: 20.3% (5,217 residents)
  • Ages 15-24: 11.8% (3,024 residents)
  • Ages 25-44: 23.1% (5,937 residents)
  • Ages 45-64: 25.1% (6,473 residents)
  • Over 65: 19.8% (5,096 residents)

What is the racial and ethnic makeup of Plymouth County?

The racial and ethnic makeup of Plymouth County is as follows:
  • White: 89.4% (23,022 residents)
  • Black or African American: 2.4% (615 residents)
  • American Indian and Alaska Native: 0.4% (110 residents)
  • Asian: 0.5% (135 residents)
  • Native Hawaiian and Other Pacific Islander: 0.4% (112 residents)
  • Two or More Races: 4.8% (1,222 residents)
  • Other: 2.1% (531 residents)

What percentage of the population in Plymouth County are U.S.-born citizens?

U.S.-born citizens represent 95.5% of the population in Plymouth County.

How many housing units are there in Plymouth County?

There are 10,891 housing units in Plymouth County, reflecting a +0.3% change compared to the previous year, according to the latest data from the U.S. Census Bureau.

How many households are in Plymouth County and what is the average household size?

Plymouth County has a total of 10,313 households, with an average of 2 people in each.

What is the median household income in Plymouth County?

Plymouth County has a median household income of $83,251, representing a +2.0% shift from the previous year, according to the U.S. Census Bureau.

What is the employment rate and job market overview for Plymouth County?

The employment rate is 97.8% in Plymouth County, with a workforce of 13,519 residents. Here’s a detailed breakdown of the local job market:

Job types:
  • White-collar workers: 67.2% (9,090 residents)
  • Blue-collar workers: 32.8% (4,429 residents)

Places of employment:
  • Self-employed: 13.7% (1,855 residents)
  • Private companies: 64.3% (8,696 residents)
  • Governmental workers: 11.9% (1,607 residents)
  • Not-for-profit companies: 10.1% (1,361 residents)

Data source & methodology

The demographic data on this page was sourced from the latest U.S. Census Bureau release—the 2019–2023 American Community Survey (ACS) 5-year estimates.

The information, issued annually, is compiled and published by the Point2Homes Research Team as soon as new data becomes available.

No representation, guarantee, or warranty is made concerning the accuracy or completeness of modified or aggregated information for particular areas.

Page last updated: September 2025