City · Iowa
Alton, Iowa
Alton, city, in Sioux County, Iowa. Alton had 1,254 residents on July 1, 2025 by the Census Bureau's estimate, up 1.4% since 2020; the 2020 Census counted 1,248 and the ACS 2020-2024 5-year estimates put it at 1,459 (±260). GEOID 1901585.
Residents, July 2025 estimate
1,254
Census Bureau estimate (no margin published)
2020 Census count: 1,248 · ACS 2020-2024: 1,459 ±260
Median household income
$98,036
±$14,555 (90% margin)
Iowa: $75,059
Median home value
$218,900
±$17,814 (90% margin)
Iowa: $208,000
Median gross rent
$813
±$732 (90% margin)
Iowa: $972
Where is Alton and what county is it in?
Alton is a city in Sioux County, Iowa. It covers 1.9 square miles of land, 653 residents per square mile in 2020.
Source: 2024 Gazetteer and 2020 place-by-county files, U.S. Census Bureau · Census reference files
How many people live in Alton, and is it growing?
The Census Bureau estimates that 1,254 people lived in Alton on July 1, 2025, up 1.4% since 2020, in line with Iowa (+1.5%). The 2020 Census counted 1,248 residents. The 2020-2024 American Community Survey, a five-year sample, puts the population at 1,459 (±260).
| Measure | Alton | Sioux County | Change since 2015-2019 |
|---|---|---|---|
| Total population | 1,459 ±260 | 36,212 | no clear change |
| Households | 592 ±112 | 12,690 | no clear change |
| Average household size | 2.46 ±0.24 | 2.67 | no clear change |
| Housing units | 650 ±114 | 13,285 | no clear change |
Alton's population since 2000
From 1,095 in 2000 to 1,254 in 2025: up 14.5%. The 2000, 2010 and 2020 figures are census counts, each for Alton as it was drawn that year: a place that annexed land, or a community that has since incorporated, covered a different area then. The 2005 figure is the Census Bureau's intercensal estimate, revised to fit the 2000 and 2010 counts and drawn on 2010 boundaries; 2015 and 2025 are July 1 estimates made from the census before them.
Source: The 2000, 2010 and 2020 Census counts and the Census Bureau's population estimates (intercensal 2000-2010, Vintage 2020, Vintage 2025) · Census population estimates
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); Census PEP Vintage 2025 (SUB-EST2025, CO-EST2025); 2020 Census P.L. 94-171 · Check it at data.census.gov
Who lives in Alton?
The median resident of Alton is 38.1 years old; 21.7% are under 18 and 13.9% are 65 or older. The largest group is non-Hispanic white residents at 86.9%, then Hispanic or Latino residents (of any race) at 6.0%.
| Measure | Alton | Sioux County | Change since 2015-2019 |
|---|---|---|---|
| Median age | 38.1 ±6.2 | 33.8 | no clear change |
| Under 18 years | 21.7% ±4.9 pts | 27.2% | – |
| 65 years and over | 13.9% ±3.6 pts | 16.2% | – |
| Male | 51.3% ±3.7 pts | 50.6% | – |
| Hispanic or Latino (any race) | 6.0% ±5.6 pts | 14.3% | – |
| White alone, not Hispanic | 86.9% ±5.1 pts | 82.8% | no clear change |
| Black or African American alone, not Hispanic | 2.2% ±1.9 pts | 0.6% | – |
| Asian alone, not Hispanic | 1.0% ±1.7 pts | 0.5% | – |
| American Indian and Alaska Native alone, not Hispanic | 0.0% ±1.7 pts | 0.1% | – |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.0% ±1.7 pts | 0.0% | – |
| Two or more races, not Hispanic | 4.0% ±3.2 pts | 1.3% | – |
| Some other race alone, not Hispanic | 0.0% ±1.7 pts | 0.3% | – |
| Born outside the United States | 2.3% ±2.5 pts | 8.5% | – |
| Speak a language other than English at home (age 5+) | 5.6% ±3.0 pts | 12.5% | – |
| Civilian veterans (age 18+) | 4.2% ±2.2 pts | 3.7% | – |
| With a disability | 8.3% ±3.0 pts | 9.0% | – |
| No health insurance coverage | 1.5% ±1.5 pts | 5.8% | – |
| High school graduate or higher (age 25+) | 96.7% ±2.5 pts | 90.9% | – |
| Bachelor's degree or higher (age 25+) | 24.3% ±5.0 pts | 30.6% | no clear change |
| Graduate or professional degree (age 25+) | 6.8% ±3.8 pts | 8.3% | – |
| Lived in the same house a year earlier | 83.4% ±9.9 pts | 90.6% | – |
| Moved from another state in the past year | 0.4% ±0.6 pts | 1.9% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profiles DP02, DP05) · Check it at data.census.gov
What do households in Alton earn?
Half of Alton's 592 households earn less than $98,036 a year (±$14,555), against $86,098 in Sioux County and $75,059 in Iowa. In 2015-2019 it was $87,234 in 2024 dollars; the margins of error cannot tell the two periods apart. 2.6% of residents live below the poverty line.
| Measure | Alton | Sioux County | Change since 2015-2019 |
|---|---|---|---|
| Median household income | $98,036 ±$14,555 | $86,098 | no clear change |
| Mean household income | $108,810 ±$12,441 | $104,988 | – |
| Per capita income | $46,530 ±$6,545 | $37,166 | no clear change |
| People below the poverty line | 2.6% ±1.7 pts | 6.7% | – |
| Children under 18 below the poverty line | 3.2% ±4.1 pts | 6.4% | – |
| Households receiving SNAP | 0.8% ±1.0 pts | 2.8% | – |
| Households with a computer | 92.9% ±3.9 pts | 95.2% | – |
| Households with a broadband subscription | 87.8% ±5.8 pts | 92.4% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What does housing cost in Alton?
Owners occupy 87.8% of Alton's occupied homes and renters 12.2%. The median owner-occupied home is valued at $218,900 by its owner (±$17,814).
| Measure | Alton | Sioux County | Change since 2015-2019 |
|---|---|---|---|
| Median home value (owner-occupied) | $218,900 ±$17,814 | $250,100 | +$53,002 |
| Median gross rent | $813 ±$732 | $908 | – |
| Renters paying 35% or more of income on rent | 8.5% ±12.6 pts | 24.8% | – |
| Median monthly owner costs, with a mortgage | $1,585 ±$171 | $1,654 | – |
| Owner-occupied homes | 87.8% ±6.1 pts | 76.1% | no clear change |
| Renter-occupied homes | 12.2% ±6.1 pts | 23.9% | – |
| Housing units | 650 ±114 | 13,285 | no clear change |
| Homeowner vacancy rate | 0.0% ±4.7 pts | 0.0% | – |
| Rental vacancy rate | 0.0% ±28.6 pts | 0.4% | – |
| Single-family detached homes | 81.2% ±6.2 pts | 79.7% | – |
| Mobile homes | 4.3% ±3.7 pts | 1.8% | – |
| Built 2020 or later | 1.1% ±1.4 pts | 1.5% | – |
| Built 2010 to 2019 | 4.8% ±2.3 pts | 9.8% | – |
| Built 1939 or earlier | 23.5% ±6.7 pts | 21.1% | – |
| Households with no vehicle | 1.7% ±1.6 pts | 2.9% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP04) · Check it at data.census.gov
How many new homes is Alton building?
Builders took permits for 6 new housing units in Alton in 2025 (6 in single-family houses), 4.8 per 1,000 residents against 4.2 across Iowa.
Counts of units in permits a local office issued; not every permitted unit is built. A year marked with months was reported for part of the year.
Source: Building Permits Survey, annual place files 2019-2025, U.S. Census Bureau · Census Building Permits Survey
How do people in Alton work and get to work?
90.3% of Alton's workers drive alone and 4.3% work from home. The average trip to work takes 14.7 minutes.
| Measure | Alton | Sioux County | Change since 2015-2019 |
|---|---|---|---|
| In the labor force (age 16+) | 80.0% ±4.6 pts | 70.3% | – |
| Unemployment rate | 2.5% ±1.9 pts | 1.5% | – |
| Drove alone to work | 90.3% ±3.9 pts | 76.0% | – |
| Carpooled | 3.5% ±2.6 pts | 6.0% | – |
| Public transportation | 0.3% ±0.6 pts | 0.3% | – |
| Walked | 1.1% ±1.1 pts | 3.4% | – |
| Worked from home | 4.3% ±2.3 pts | 12.8% | no clear change |
| Mean travel time to work | 14.7 min ±2.6 | 13.5 min | no clear change |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What census tracts are in Alton?
No census tract lies mostly in Alton; 1 tract reaches into it (2020 census blocks).
| Tract | Residents, 2020-2024 | Median household income |
|---|---|---|
| Tract 705Sioux County | 3,040 | $102,760 |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); 2020 block assignment files (tract share = share of the tract's census blocks in Alton) · Census block assignment files
How does Alton compare with other places in Iowa?
By the Census Bureau's July 2025 estimates, Alton is the 9,434th-most populous of the 19,476 U.S. incorporated places that have one and the 230th-most populous of 939 in Iowa.
Alton ranks 41st of 279 places in Iowa with 1,000 or more residents and a reliable estimate, by median household income.
| Measure | Rank | Of |
|---|---|---|
| Population, July 2025 estimate | 230th | 939 |
| Growth 2020-2025 (PEP) | 87th | 275 |
| Residents per square mile | 239th | 279 |
| Median household income | 41st | 279 |
| Per capita income | 43rd | 279 |
| Median home value | 73rd | 279 |
| Poverty rate | 231st | 232 |
| Bachelor's degree or higher | 140th | 279 |
| Median age | 175th | 279 |
| Owner-occupied share | 23rd | 279 |
| Work from home | 209th | 221 |
| Travel time to work | 241st | 279 |
Alton's figures with every place in Iowa (CSV)
Every place in Iowa, sortable · Compare Alton with other places
Source: PlainCities ranks computed from the American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) and PEP Vintage 2025 · How ranks are computed
How reliable are the figures for Alton?
23 of the 57 figures for Alton on this page carry a coefficient of variation over 40% and are marked with a ring: they come from a small sample, so read them as rough.
The American Community Survey samples about one household in eight over five years, so every figure is an estimate with a 90% margin of error (shown under each value). A ring marks an estimate whose coefficient of variation is over 40%. A change is called only when the gap between the two periods is larger than their combined 90% margin (the square root of the sum of the two squared margins), the Census Bureau's test. How to read a margin of error.
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026): margins of error as published · ACS technical documentation
How these figures are made: methodology and release checks · reading a margin of error · every state · corrections
Not on this page: crime, weather and schools for Alton are other agencies' records. Crime: the FBI's Crime Data Explorer · climate: NOAA's U.S. Climate Normals · schools: the National Center for Education Statistics' public schools in Alton.