What city is ZIP code 51109?

ZIP code 51109 is in Sioux City, IA (Plymouth County).

What county is ZIP code 51109 in?

ZIP code 51109 is mostly in Plymouth County, Iowa.

How many people live in ZIP code 51109?

About 3,606 people live in the 51109 ZIP Code Tabulation Area, based on American Community Survey 5-year estimates.

Checked Oct 26, 2026

ZIP Code 51109

Sioux City, IA, Plymouth County

Population

3,606

Land area

17.6sq mi

People per sq mi

205

City

Sioux City

ZIP 51109 and nearby ZIP codes

Full map

ZIP 51109 at a glance

ZIP 51109 (Sioux City) is about 3.6 times as dense as Iowa as a whole.
The median household income is $79,034, 5% above the Iowa median of $75,059.
A typical owner-occupied home is valued at $130,900 (37% below Iowa) and median rent is $627 a month.

Local data for ZIP 51109

Counts from official public data

Housing and community stats

ZIP 51109, American Community Survey 2020-2024

Full profile

Median household income

$79,034

Poverty rate

16.1%

Median home value

$130,900

Prices +16.7% in a year

Median rent

$627/mo

Homeownership

87.0%

Bachelor's or higher

3.4%

Median age

39.4

Average commute

16.4 min

Income, education and commute

Economy and federal money

Businesses, pandemic loans and political donations

Details

Business establishments

ZIP Business Patterns 2023

Employees

349

$9.5M annual payroll

PPP loans

$1.4M

56 loans

Campaign donations

$5,081

16% D, 33% R, 2026 cycle

PPP loans in this ZIP

Environment and hazard risk

ZIP 51109, from FEMA, NOAA and EPA

Full report

Natural hazard risk

Relatively Low

Top: hail

Storm events since 1996

868

Countywide, mostly hail

Flood insurance policies

0.2% of homes, county

July high / Jan low

86° / 9°F

30.3 inches of rain a year

Hazards, floods and storm history Check a flood zone

Health statistics

Share of adults in ZIP 51109, CDC PLACES estimates

All 40 measures

Obesity

40.7%

U.S. 33.3% +7.4 pts

Diabetes

13.3%

U.S. 12.1% +1.2 pts

Smoking

19.1%

U.S. 12.8% +6.3 pts

Uninsured (18-64)

10.2%

U.S. 11.1% -0.9 pts

Frequently asked questions

What city is ZIP code 51109?: ZIP code 51109 is in Sioux City, IA (Plymouth County).
What county is ZIP code 51109 in?: ZIP code 51109 is mostly in Plymouth County, Iowa.
How many people live in ZIP code 51109?: About 3,606 people live in the 51109 ZIP Code Tabulation Area, based on American Community Survey 5-year estimates.

Source: U.S. Census Bureau (ZIP Code Tabulation Areas, American Community Survey) · Data as of 12/31/2023. ZIP Code Tabulation Areas closely match, but are not identical to, USPS ZIP code delivery areas.