51111
ZIP 51111 is in Sioux City, Iowa, in Woodbury County; area code 712; Central time. Sioux City has 9 ZIP codes in all.
- Type
- Standard
- Time zone
- America/Chicago
- County
- Woodbury
- Metro area
- Sioux City, IA-NE-SD
- Population
- 39
- Coordinates
- 42.4185, -96.3931
Weather right now
Asking the National Weather Service…
Where 51111 is
Approximate ZIP boundary (Census ZCTA 2020). ZIP codes are mail routes, not areas, so the shape shown is the Census tabulation area that approximates it.
- 🔢 Type 51111 into a pocket calculator and turn it upside down: IIIIS — not quite a word, sorry.
- ➕ As a number, 51,111 = 3 × 3 × 3 × 3 × 631. Its digits add up to 9, a total 375 other ZIP codes share.
- 💾In binary, the way a computer stores it:
1100011110100111 - 🏠 Its numerical neighbours: 51109 (Sioux City, IA, 14 mi away) and 51201 (Sheldon, IA, 59 mi away).
- 🔄 Backwards, 51111 becomes 11115, which is not a ZIP code at all.
- 🧭 Farther north than 78% of all ZIP codes, and farther west than 72%.
- 🎯212 miles northeast of the geographic center of the Lower 48, near Lebanon, Kansas.
- 🌏 Dig straight through the Earth from 51111 and you would come out at 42.42°S, 83.61°E — 801 miles from Port-aux-Français, French Southern Territories, the nearest big city to that spot.
- ☀Longest day of the year: 15h 17m of daylight. Shortest: 9h 04m.
- 📏 At 6.1 square miles of land, 51111 is bigger than 21% of ZIP codes — room for about 4.6 Central Parks.
- Working out the sun…
- Checking the USGS…
Source: USGS.
People and housing
| Population | 39This ZIP39 |
|---|---|
| Households | 27This ZIP27 |
| Housing units | 27This ZIP27 |
| Median age | 26.4This ZIP26.4Iowa38.6US 38.9 |
| Bachelor's degree or higher | 0.0% |
| Population density | 6.4 / sq miThis ZIP6.4 / sq mi |
Business and tax activity
| Business establishments | 96This ZIP96 |
|---|---|
| Employees | 6,303This ZIP6,303 |
| Annual payroll | $361,874,000This ZIP$361,874,000 |
Land area
| Land area | 6.06 sq miThis ZIP6.06 sq mi |
|---|---|
| Water area | 0.24 sq miThis ZIP0.24 sq mi |
Other place names in 51111
Census places whose land this ZIP code overlaps. The Postal Service may accept other city names in an address, too.
ZIP codes near 51111
| ZIP | City | Distance |
|---|---|---|
68776 | South Sioux City, NE | 3.8 mi |
51054 | Sergeant Bluff, IA | 3.9 mi |
68731 | Dakota City, NE | 5.1 mi |
51106 | Sioux City, IA | 5.1 mi |
51102 | Sioux City, IA | 5.2 mi |
51101 | Sioux City, IA | 5.2 mi |
51105 | Sioux City, IA | 6.3 mi |
51103 | Sioux City, IA | 7.6 mi |
68030 | Homer, NE | 7.7 mi |
51104 | Sioux City, IA | 8.0 mi |
Find every ZIP code within 10 miles of 51111 →
Questions about this ZIP code
Where is ZIP code 51111?
51111 is in Sioux City, Iowa, in Woodbury County, part of the Sioux City, IA-NE-SD metropolitan area. Its published point location is 42.4185, -96.3931.
What county is 51111 in?
51111 lies in Woodbury County.
What area code is 51111?
Sioux City uses area code 712, from NANPA's telephone records.
What time zone is 51111 in?
51111 uses America/Chicago.
How many people live in 51111?
About 39 people live in ZIP code 51111, in 27 households, at 6.4 people per square mile. These are American Community Survey 5-year estimates for the ZIP Code Tabulation Area, not a headcount.
What ZIP codes are near 51111?
The closest are 68776 (3.8 mi), 51054 (3.9 mi), 68731 (5.1 mi), 51106 (5.1 mi) and 51102 (5.2 mi).
Is 51111 a PO Box ZIP code?
51111 is a standard ZIP code. A normal ZIP code with street delivery.
Download or cite
Cite this page
zipcodes.pro. “51111 ZIP Code — Sioux City, Iowa (Woodbury County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/51111
Machine-readable version of these facts:
curl https://zipcodes.pro/zip/51111.jsonUnderlying data is public domain or openly licensed — sources, vintages and licences.