Alton, IA · standard
ZIP Code 51003
Sioux County, Iowa - Census ACS demographics, housing tenure, and business patterns, benchmarked against every US ZIP.
- 1,700
- 12/sq mi Low-density area
- $101,250
- Median income Above-median income area
- $232,700
- Median home value Near-median home value
- 29.2%
- Bachelor's or higher Near-average bachelor's attainment
National ZIP placement
Alton pairs an upper-quartile household income with above-median home values, in a rural, homeowner-dominated area.
- Top 18%
- household income, US ZIPs
- Top 47%
- home value, US ZIPs
- 12
- people per sq mi
- 87%
- owner-occupied homes
Source: U.S. Census Bureau ACS 5-Year Estimates (2019–2023). Percentiles rank ZIP 51003 against every reporting US ZIP.
FHFA HPI release change
What changed in the latest House Price Index year
- FHFA House Price Index values in ZIP 51003 (Alton, IA) rose +2.9% from 2023 to 2024.
ZIP code 51003 covers 144.1 square miles in Alton, Sioux County, Iowa (a standard USPS delivery area), with a modest 1,700 residents on file, a density of 12 people per square mile, in the Chicago time zone.
ZIP 51003 lands in the middle-income range, with a median household income of $101,250 (32% above the average Iowa ZIP), while per-capita income is $44,417. Both reported hardship measures are comparatively low in absolute terms: poverty is 2.0% and unemployment is 2.0%. Housing is both higher-cost and owner-heavy: median home value is $232,700 (33% above the average Iowa ZIP), while 87.1% of occupied homes are owner-occupied and median rent is $813.
Educational attainment sits below the national norm: 29.2% of adults hold a bachelor's degree or higher, the median age is 37.1, and the average commute is -. The page also surfaces 3 ZIP codes within roughly 10 miles and 6 more in Sioux County, so 51003 can be compared with both its immediate and county-level context.
Every figure on this page is sourced from the U.S. Census Bureau American Community Survey 5-Year Estimates (including median rent) and the FHFA House Price Index, no estimates, no proprietary scoring. Verify with Census →
Top industries in ZIP 51003
Top 5 sectors by establishment count in Alton, IA
Which industries have the most business establishments in ZIP 51003.
- Construction
Construction
9 establishments
- Transportation and warehousing
Transportation and warehousing
7 establishments
- Other services (except public administration)
Other services (except public administration)
6 establishments
- Retail trade
Retail trade
5 establishments
- Wholesale trade
Wholesale trade
4 establishments
What this shows Establishment counts come from the Census ZIP Code Business Patterns program, which counts physical business locations rather than employees or revenue.
Source: U.S. Census Bureau, American Community Survey 5-Year Estimates + ZIP Code Business Patterns + FHFA HPI ACS demographics and median rent, ZBP business establishments, FHFA HPI for ZIP 51003, Alton, IA · 2023 Census ACS 5-Year Estimates use a rolling 60-month sample for stable small-geography estimates; ZBP updated annually; FHFA HPI updated quarterly/annually.
Quick Facts
1,700
Population
144.1
Area (sq mi)
12
People / sq mi
Chicago
Time Zone
standard
ZIP Type
Who lives in ZIP 51003?
37.1
Median Age
50.9%
Male
49.1%
Female
1.8%
Foreign-Born
Hispanic or Latino is an ethnicity category from the Census Bureau and may overlap with other categories above.
Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)
How much do residents earn?
$101,250
Median Household Income
+32% vs state ZIP avg
$44,417
Per Capita Income
2.0%
Poverty Rate
2.0%
Unemployment Rate
How ZIP 51003 ranks among Iowa ZIPs
Alton, IA household income vs. every Iowa ZIP code
Median household income among 911 reporting Iowa ZIPs (this ZIP's population is too small for a reliable national-corpus placement)
$101,250 Top 11% higher than 89% of 911 Iowa ZIPs
Each bar is a $20K-wide band; taller bars hold more Iowa ZIPs. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source U.S. Census Bureau, ACS 5-Year Estimates · 2019–2023
Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)
What is the education profile here?
Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)
What does housing look like?
Housing stock: occupied vs vacant
788housing units
788
Total Housing Units
730
Occupied Units
58
Vacant Units
2.65
Avg Household Size
Occupancy Type
$232,700
Median Home Value
+33% vs state ZIP avg
$813
Median Rent
1970
Median Year Built
Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)
What businesses operate in this ZIP?
Census Bureau data shows 44 business establishments in ZIP 51003, employing approximately 175 people with a combined annual payroll of $7,882,000.
44
Businesses
175
Employees
$7.9M
Annual Payroll
6
Industry Sectors
| Industry | Establishments | % of Total |
|---|---|---|
| Construction | 9 | 20.4% |
| Transportation and warehousing | 7 | 15.9% |
| Other services (except public administration) | 6 | 13.6% |
| Retail trade | 5 | 11.4% |
| Wholesale trade | 4 | 9.1% |
| Manufacturing | 3 | 6.8% |
Source: U.S. Census Bureau, ZIP Code Business Patterns (ZBP), 2023. Employment figures may include noise for disclosure avoidance.
Nearby ZIP Codes
Want a side-by-side? Compare 51003 vs 51041 →
ZIP 51003 vs its nearest neighbors, by population
Resident population of this ZIP and the closest reporting ZIP codes within ~10 miles.
- 51041
Orange City (51041)
6,976 residents
- 51003 1,700
Alton (51003)
1,700 residents
- 51238 1,184
Hospers (51238)
1,184 residents
- 51022 789
Granville (51022)
789 residents
What this shows Among its immediate neighbors, ZIP 51003 ranks #2 by population - useful context the national average alone can't give.
ZIP 51003 vs its nearest neighbors, by median income
Median household income of this ZIP and the closest reporting ZIP codes within ~10 miles.
- 51003
Alton (51003)
$101,250 median income
- 51022
Granville (51022)
$96,505 median income
- 51041
Orange City (51041)
$83,643 median income
- 51238
Hospers (51238)
$74,000 median income
What this shows By household income, ZIP 51003 ranks the highest of 4 neighboring ZIPs, local affluence varies block to block, not just metro to metro.
Nationwide ZIPs with similar ACS profiles
Two Census-derived peer sets for ZIP 51003, both outside IA so the neighborhoods are not geographic containment (Nearby and same-county blocks stay local).
Similar population
Nearest cross-state ZIPs by resident population (1,700 here; floor ≥1,000).
Similar median household income
Nearest cross-state ZIPs by ACS median household income.
More ZIP Codes in Sioux County
Related Areas
Frequently Asked Questions
What county is ZIP code 51003 in?
ZIP code 51003 (Alton) is located in Sioux County, Iowa. Sioux County contains multiple ZIP codes, see the full list at /counties/sioux-ia.
What is the population of ZIP code 51003?
ZIP code 51003 in Alton, IA has a population of 1,700 according to the Census Bureau ACS 2023 estimates.
What is the median household income in ZIP 51003?
The median household income in ZIP 51003 is $101,250, which is 33% above the national average of $76,288.
What is the average home value in ZIP 51003?
The median home value in ZIP 51003 is $232,700, which is 16% below the national average of $278,155.
What is the demographic makeup of ZIP 51003?
The largest racial group in ZIP 51003 is White at 94.4%. Hispanic or Latino residents make up 5.4% of the population.
How many businesses are in ZIP code 51003?
ZIP code 51003 has 44 business establishments employing approximately 175 people, according to Census Bureau ZIP Code Business Patterns (ZBP) 2023 data.
What are the main industries in ZIP code 51003?
The top industries by establishment count in ZIP 51003 are: Construction (9), Transportation and warehousing (7), Other services (except public administration) (6). There are 6 industry sectors represented in total.
What is the education level in ZIP code 51003?
In ZIP code 51003, 59.8% of residents aged 25+ have a high school diploma or higher, and 29.2% hold a bachelor's degree or higher. These figures come from the Census Bureau ACS 5-Year Estimates (2023).
What percentage of residents own vs. rent in ZIP 51003?
In ZIP code 51003, approximately 87.1% of occupied housing units are owner-occupied and 12.9% are renter-occupied, based on Census ACS 2023 data.
What is the poverty rate in ZIP code 51003?
The poverty rate in ZIP code 51003 is 2.0% according to Census Bureau ACS 2023 estimates. This measures the percentage of the population living below the federal poverty threshold.
Related
Take this with you
What to do with ZIP 51003's numbers, next.
- See how ZIP 51003 compares to a neighboring ZIP code on the same Census fields Compare this ZIP
- Check where Alton, IA ranks among every U.S. ZIP code on income, education, or homeownership View national rankings
- Save this ZIP to your shortlist to track alongside others you're considering View your shortlist
ZIP Code Tabulation Areas (ZCTAs) are Census Bureau approximations of USPS ZIP codes; figures describe the ZCTA area, not any single address within it.