Demographics of Hamilton County, Iowa

Hamilton County, Iowa had 14,944 people on July 1, 2025, by the Census Bureau’s estimate: −70 since July 2020. Age, income, poverty, housing and origin below come from the American Community Survey, averaged over 2020–2024, each with its margin of error.

Hamilton County, in four figures

14,944
Population: July 1, 2025, Vintage 2025 estimate.; −0.5%
Change since July 2020: −70 people.; 41.7 ±0.8
Median age: ACS 2020–⁠2024.; $72,432 ±$8,050
Median household income: ACS 2020–⁠2024, in 2024 dollars.

Population, year by year

July 1 estimates from the Census Bureau’s Vintage 2025. Each year's change is births less deaths, net moves from abroad and net moves from elsewhere in the country, with the Bureau's small residual. The 2020 row's components run 3 months, from the April census to July 1.

Hamilton County, Iowa's population shrank 0.5% from July 2020 to July 2025, against +3.1% nationally

The July 1 estimate of Hamilton County, Iowa's resident population and the nation's, each year of the Census Bureau's Vintage 2025, as a share of its July 2020 level (= 100).

U.S. Census Bureau — Census Bureau population estimates — counties and Puerto Rico municipios, with components of change

About this chart

The figures

Hamilton County, Iowa's population shrank 0.5% from July 2020 to July 2025, against +3.1% nationally. The July 1 estimate of Hamilton County, Iowa's resident population and the nation's, each year of the Census Bureau's Vintage 2025, as a share of its July 2020 level (= 100).
July 1	Population	Index	United States
2020	15,014	100.0	100.0
2021	14,874	99.1	100.2
2022	14,880	99.1	100.7
2023	14,914	99.3	101.6
2024	14,998	99.9	102.5
2025	14,944	99.5	103.1

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Population of Hamilton County, Iowa on July 1 of each year, Vintage 2025
July 1	Population	Change	Births less deaths	From abroad	From elsewhere in the country
2020	15,014	−26	−9	0	−18
2021	14,874	−140	−52	+2	−92
2022	14,880	+6	+3	+50	−40
2023	14,914	+34	−7	+116	−76
2024	14,998	+84	+26	+157	−97
2025	14,944	−54	+23	+18	−95

Age, 2020–2024

The median age is 41.7 ±0.8: for men 40.1 ±0.6 and for women 44.0 ±0.9. Shares are of everyone the survey counts, in the Bureau’s sex-by-age table (B01001).

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People in Hamilton County by age, ACS 2020–2024
Age	People	Share	Iowa	United States
Under 5	768 ±50	5.2% ±0.3	5.9% ±<0.1	5.6% ±<0.1
5 to 17	2,779 ±212	18.7% ±1.4	17.0% ±0.1	16.3% ±<0.1
18 to 24	1,000 ±111	6.7% ±0.7	10.0% ±0.1	9.1% ±<0.1
25 to 44	3,465 ±251	23.3% ±1.7	25.1% ±0.1	26.9% ±<0.1
45 to 64	3,717 ±226	25.0% ±1.5	23.9% ±0.1	24.8% ±<0.1
65 and over	3,157 ±266	21.2% ±1.8	18.1% ±0.1	17.2% ±<0.1

Income and poverty, 2020–2024

Median household income is $72,432 ±$8,050, and income per person $40,191 ±$2,678, in 2024 dollars. The median is $75,059 ±$418 in Iowa and $80,734 ±$166 in the United States.

Households by income

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Households in Hamilton County by income, ACS 2020–2024
Household income	Households	Share	Iowa	United States
Under $25,000	950 ±228	14.8% ±3.5	13.9% ±0.2	14.6% ±<0.1
$25,000 to $49,999	1,277 ±237	19.8% ±3.6	18.5% ±0.3	16.7% ±<0.1
$50,000 to $74,999	1,102 ±194	17.1% ±3.0	17.5% ±0.3	15.5% ±<0.1
$75,000 to $99,999	967 ±196	15.0% ±3.0	14.0% ±0.3	12.6% ±<0.1
$100,000 to $149,999	1,235 ±177	19.2% ±2.7	18.7% ±0.3	17.5% ±<0.1
$150,000 to $199,999	368 ±107	5.7% ±1.7	8.8% ±0.2	9.6% ±<0.1
$200,000 or more	535 ±119	8.3% ±1.8	8.6% ±0.2	13.4% ±0.1

Poverty by age

The poverty rate is the share of people whose family income is below the federal threshold for their family’s size, of everyone for whom the Bureau determines it (B17020).

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Poverty rate in Hamilton County by age, ACS 2020–2024
Age	Below poverty	Rate	Iowa	United States
All ages	1,085 ±306	7.4% ±2.1	11.1% ±0.2	12.5% ±0.1
Under 18	189 ±89	5.4% ±2.5	12.9% ±0.3	16.1% ±0.1
18 to 59	498 ±216	7.1% ±3.1	11.4% ±0.3	11.6% ±0.1
60 and over	398 ±127	9.5% ±3.0	8.8% ±0.2	11.0% ±<0.1

Housing, 2020–2024

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Housing in Hamilton County, ACS 2020–2024
Measure	Hamilton County	Iowa	United States
Housing units	7,040 ±46	1,437,699 ±523	143,775,355 ±10,234
Occupied	91.4% ±2.9	91.5% ±0.3	89.9% ±0.1
Vacant	8.6% ±2.9	8.5% ±0.3	10.1% ±0.1
Owner occupied	73.4% ±3.5	71.7% ±0.3	65.2% ±0.3
Renter occupied	26.6% ±3.3	28.3% ±0.3	34.8% ±0.1
Median home value	$156,400 ±$11,246	$208,000 ±$1,141	$332,700 ±$236
Median gross rent	$877 ±$51	$972 ±$6	$1,413 ±$2
Median year built	1953 ±3	1972 ±1	1980 ±1

Occupied and vacant are shares of all housing units; owner and renter occupied are shares of occupied units. Value and rent are medians in 2024 dollars.

Origin and place of birth, 2020–2024

Hispanic or Latino origin is not a race in the Census Bureau’s tables. Here the people of Hispanic origin, of any race, are one row, and everyone else is counted by race alone (B03002), so the rows add to the whole.

Hispanic origin and race

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People in Hamilton County by Hispanic origin and race, ACS 2020–2024
Origin	People	Share	Iowa	United States
Hispanic or Latino	1,510 ±0	10.1% ±<0.1	7.3% ±<0.1	19.3% ±<0.1
White alone, not Hispanic	12,471 ±48	83.8% ±0.3	82.3% ±0.1	57.4% ±<0.1
Black alone, not Hispanic	144 ±45	1.0% ±0.3	3.8% ±0.1	11.9% ±<0.1
Asian alone, not Hispanic	338 ±101	2.3% ±0.7	2.5% ±<0.1	5.9% ±<0.1
American Indian and Alaska Native alone, not Hispanic	0 to 56	0% to 0.4%	0.2% ±<0.1	0.5% ±<0.1
Native Hawaiian and Other Pacific Islander alone, not Hispanic	0 to 62	0% to 0.4%	0.2% ±<0.1	0.2% ±<0.1
Some other race alone, not Hispanic	17 to 93	0.1% to 0.6%	0.3% ±<0.1	0.6% ±<0.1
Two or more races, not Hispanic	321 ±101	2.2% ±0.7	3.5% ±0.1	4.3% ±<0.1

A range (the estimate less and plus its margin) where the Bureau's estimate is too uncertain to state as one number: a coefficient of variation over 30%.

Place of birth and citizenship

“Born a citizen outside the states” counts people born in Puerto Rico, the island areas, or abroad to American parents. Naturalized citizens and those who are not citizens together make up the people born abroad (B05002).

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People in Hamilton County by place of birth and citizenship, ACS 2020–2024
Born	People	Share	Iowa	United States
Born in the state	11,415 ±357	76.7% ±2.4	69.6% ±0.2	57.3% ±<0.1
Born in another state	2,282 ±331	15.3% ±2.2	23.8% ±0.2	26.9% ±<0.1
Born a citizen outside the states	98 to 378	0.7% to 2.5%	0.7% ±<0.1	1.7% ±<0.1
Born abroad	951 ±247	6.4% ±1.7	5.9% ±0.1	14.1% ±<0.1
Naturalized citizens	94 to 296	0.6% to 2.0%	2.6% ±0.1	7.4% ±<0.1
Not citizens	756 ±276	5.1% ±1.9	3.3% ±0.1	6.8% ±<0.1

A range (the estimate less and plus its margin) where the Bureau's estimate is too uncertain to state as one number: a coefficient of variation over 30%.

Hamilton County among the counties of Iowa

49th of 99 by population, July 2025. Every one is listed on the Iowa page.

Counties of Iowa near Hamilton County in population, July 2025
County	July 2025	Change since 2020
Iowa County	16,504	−1.0%
Hardin County	16,455	−2.2%
Crawford County	16,237	−1.5%
Clay County	16,202	−0.9%
Jefferson County	15,291	−2.5%
Hamilton County	14,944	−0.5%
Floyd County	14,901	−4.5%
Page County	14,856	−2.3%
Mills County	14,793	+2.6%
Harrison County	14,623	+0.4%
Kossuth County	14,322	−3.2%

Elsewhere on the site

Sources

Census Bureau population estimates — counties and Puerto Rico municipios, with components of change — U.S. Census Bureau · U.S. Government work · retrieved September 25, 2026
American Community Survey 5-year estimates — table-based Summary File · U.S. Government work

Data retrieved September 25, 2026