Zip Code 51108 — Sioux City, IA
51108 is a ZIP Code associated with Sioux City, IA, located within Plymouth. 51108 ranks #2 out of 11 ZIP codes in Plymouth County by population (and #127 out of 970 in IA). The area supports an estimated population of 5,960 residents across Data Pending housing units, with a population density of 50.0 people per square mile.
WorldPlaceData database updated: October 2026
📍 View location on OpenStreetMap (42.566250, -96.348580)
| Data Metric | Local Statistic |
|---|
| Postal / Zip Code | 51108 |
| Primary City | Sioux City |
| State / Province | IA |
| County | Plymouth |
| Total Population | 5,960 |
| Median Household Income | Data Pending |
| Total Housing Units | Data Pending |
| Population Density | 50.0 people/sq mi |
| Timezone | America/Chicago |
How 51108 Compares
| Metric | ZIP 51108 | Plymouth County | IA State Average |
|---|
| Population | 5,960 | 34,178 (Total) | 3,210,984 (Total) |
| Average ZIP Income | Data Pending | N/A | N/A |
| Population Density | 50.0 /sq mi | -- | -- |
| County Pop Rank | #2 of 11 | -- | -- |
Nearby ZIP Codes
Data Sources & Methodology: Geographic coordinates and ZIP Code assignments are derived from underlying geographic and postal datasets. Note that ZIP Codes are USPS postal delivery areas, while Census ZCTAs are statistical approximation areas. Read full methodology →