Residential delivery area · Iowa
ZIP Code 51109: Sioux City, IA
ZIP code 51109 uses the postal name Sioux City, Iowa and lies mostly in Plymouth County (90% of its land) with the rest in Woodbury County (Census 2020 ZIP-county file). About 3,600 people live there (Census Bureau, ACS 2020-2024), the 6th most populous of Sioux City's 8 residential ZIP codes. Median household income is $79,034 (Census Bureau, ACS 2020-2024). By Census place, 10% of its land lies in Sioux City; 90% is outside any Census place.
- ACS2020-24
- Census2020
- FHFA2025
- ZBP2023
- IRS2022
- Town
- Sioux City · 8 residential ZIPs
- County
- Plymouth County (90%); Woodbury County (10%)
- Census places
- Sioux City
- Micro area
- Le Mars, IA
- House district
- IA-4 119th Congress
- State
- Iowa
- Time zone
- Central
- Land area
- 17.6 sq mi · 205 people per sq mi
- PO Box ZIPs
- 51102 also use the name Sioux City
Where is ZIP code 51109?
51109 centers on 42.610°, -96.470° and covers 17.6 square miles of land plus 0.8 of water. It borders 7 ZIP codes: 57038, 51103, 57049, 51108, 51062, 51024, 68776.
The map draws ZIP code areas only. For the streets inside 51109, open its center on OpenStreetMap.
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries and the 2023 Gazetteer (2020 ZCTAs); ZIP-to-county shares, Census places and House districts (119th Congress) from the Census 2020 relationship files (shares of land); metro area from the OMB delineation (July 2023); town name and time zone from simplemaps US ZIP Codes (CC BY 4.0).
How does 51109 compare with the rest of Sioux City?
| Measure | 51109 | In Sioux City | In Plymouth County | In IA |
|---|---|---|---|---|
| People (ACS 2020-2024) | 3,606 | 6th of 8 | 3rd of 14 | 173rd of 970 |
| Median household income | $79k | not ranked | not ranked | not ranked |
| Median home value | $131k | 5th of 6 | 9th of 9 | 361st of 423 |
51109's median household income is not ranked: its 90% margin of error (±$20,375) is more than a quarter of the figure ($79,034). Rankings use ZIP codes of 1,000 or more people living in households, with margins at most 25% of the figure.
It is denser than 63% of U.S. residential ZIP codes. ZIP codes at the ACS caps ($250,000 or more for household income, $2,000,000 or more for home value) share the top rank.
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01003, B19013, B25077); ranks by PlainZIP over residential ZIP codes (ZCTAs).
How many people live in 51109?
The 2020 Census counted 3,109 people in 51109; the ACS, which samples households over 2020-2024, estimates 3,606. Between the 2010 and 2020 censuses its population grew 0.4% (its boundary stayed at least 90% the same).
- People, ACS 2020-2024
- 3,606±587 (90% margin)
- 2020 Census count
- 3,109+0.4% since 2010 (3,098)
- Households
- 1,447
- Median age
- 39.4
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01003, B01002, B11001); 2020 Census (DHC P1); 2010 Census (SF1 P1).
Who lives in 51109?
Of the 3,606 people the ACS estimates in 51109, 24.2% are under 18 and 17.8% are 65 or older. The largest group by race and Hispanic origin is White (not Hispanic) (68.7%), then Hispanic or Latino (23.3%).
- Under 1824.2%
- 18 to 6458.1%
- 65 and older17.8%
- White, not Hispanic68.7%
- Hispanic or Latino23.3%
- Black, not Hispanic6.5%
- Other or two or more1.4%
- Asian, not Hispanic0.1%
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01001 age by sex, B03002 Hispanic or Latino origin by race); shares of the estimated population, small ZIP codes carry wide margins.
What do households in 51109 earn?
Median household income is $79,034 (ACS 2020-2024). It is not measurably different from 2015-2019 ($74,816 in 2024 dollars): the change is within the surveys' margins of error.
- Median household income
- $79,034±$20,375
- Income per person
- $37,934
- Below the poverty line
- 16.1%
- Unemployed (of the labor force)
- 1.9%
- Adults 25+ with a bachelor's degree
- 3.4%
- Adjusted gross income per tax return, 2022
- $55,6901,440 returns; wages 75% of AGI (IRS)
Source: U.S. Census Bureau, ACS 2020-2024 and 2015-2019 5-year estimates (B19013, B19301, B17001, B23025, B15003; 2015-2019 dollars converted with the BLS CPI-U, 1.22699); IRS Statistics of Income, ZIP code data, tax year 2022 (adjusted gross income per return, filed under the address on the return).
What are homes worth in 51109?
FHFA's house price index for 51109, built from repeat sales and appraisals of the same homes, rose 97% from 2015 to 2025 and rose 49% from 2020 to 2025, and moved +16.7% in 2025.
- Median home value (owners' estimate)
- $130,900
- Median gross rent
- $627
- Homes owned by their occupants
- 87.0%
- Housing units
- 1,488
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B25077, B25064, B25003, B25001); FHFA House Price Index, annual five-digit ZIP, updated 2026-03-31.
What businesses are in 51109?
57 business establishments had a location in this ZIP code in 2023, 1 more than in 2018; the most are in retail trade (ZIP Code Business Patterns).
- Retail trade16
- Other services (except public administration)11
- Accommodation and food services6
- Construction5
- Health care and social assistance5
- Arts, entertainment, and recreation3
Source: U.S. Census Bureau, ZIP Code Business Patterns 2023 and 2018 (establishments with paid employees, by the business's ZIP code).
Which ZIP codes are next to 51109?
| ZIP | Town | People | Household income | Distance |
|---|---|---|---|---|
| 57038 | Jefferson, SD | 1,796 | $106k | 5.9 mi |
| 51103 | Sioux City | 16,895 | $58k | 6.3 mi |
| 57049 | North Sioux City, SD | 7,962 | $93k | 6.3 mi |
| 51108 | Sioux City | 5,960 | $81k | 6.7 mi |
| 51062 | Westfield | 503 | – | 6.9 mi |
| 51024 | Hinton | 2,081 | $114k | 10.6 mi |
| 68776 | South Sioux City, NE | 15,373 | $69k | 10.6 mi |
| 51104 | Sioux City | 23,197 | $75k | 6.2 mi (near) |
| 51105 | Sioux City | 10,415 | $52k | 8.8 mi (near) |
| 51101 | Sioux City | 1,031 | $15k | 8.9 mi (near) |
Source: PlainZIP from the Census 2020 ZCTA boundaries (shared edges) and internal points; figures ACS 2020-2024.