Zip Code 51103 — Sioux City, IA

ZIP Code 51103 is associated with Sioux City, IA, in Woodbury County. The listed population estimate is 16,895; estimated density is 540.7 people per square mile. Among records with population estimates, it ranks #3 of 20 in Woodbury County and #51 of 969 in IA.
Page generated: 2026-10-08. This is not the source data release date.

📍 View location on OpenStreetMap (42.521730, -96.446420)

Data MetricLocal Statistic
Postal / Zip Code51103
Primary CitySioux City
State / ProvinceIA
CountyWoodbury
Total Population16,895
Population Density540.7 people/sq mi
TimezoneAmerica/Chicago

How 51103 Compares

MetricZIP 51103Woodbury County recordsIA records
Population estimate16,89597,439 (sum)3,210,984 (sum)
Population Density540.7 /sq mi----
County population rank#3 of 20----
State population rank#51 of 969----

Regional sums combine the population estimates in the listed ZIP records; they are not official county or state population totals.

Explore More ZIP Codes

Nearby ZIP Codes in IA

ZIP CodeCityDistancePopulation estimate
ZIP 51104Sioux City2.4 mi23,197
ZIP 51101Sioux City3.3 mi1,031
ZIP 51105Sioux City4.1 mi10,415
ZIP 51109Sioux City5.6 mi3,606
ZIP 51108Sioux City5.9 mi5,960

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 →