ZIP Code 51023

51023 is one of Iowa's ZIP codes, delivering to addresses in Hawarden, Sioux County.

City: Hawarden
County: Sioux County
State: Iowa
Prefix: 510xx

Where this code sits

51023 is part of the 510xx range, the group of codes handled by one mail processing centre. It is the only ZIP code delivering to Hawarden.

Hawarden Iowa ZIP codes →

Area codes over the same ground

Postal and telephone geography are drawn separately, so these codes cover the area 51023 delivers to without sharing its boundary.

712 Area code 712

ZIP codes nearest 51023

The ZIP codes whose reference points sit closest to 51023.
ZIP code	Distance	Delivers to
ZIP code 51011	6.2 mi	Chatsworth, IA
ZIP code 51027	7.9 mi	Ireton, IA
ZIP code 57001	8.1 mi	Alcester, SD
ZIP code 57034	9.3 mi	Hudson, SD
ZIP code 51001	12 mi	Akron, IA
ZIP code 57027	14 mi	Fairview, SD
ZIP code 51036	16 mi	Maurice, IA
ZIP code 51250	16 mi	Sioux Center, IA

Straight-line distance between place reference points, not driving distance. Where a place has no Census Gazetteer point, its postal centroid is used instead.

Each point is the reference point for 51023, plotted from its record coordinates.

Reference points and footprint
Not an official NANPA boundary
Not a USPS delivery area

Scope ZIP code 51023. Source GeoNames US postal codes (2026-07 postal dump) and Census 2024 county Gazetteer (2024 Gazetteer). Updated 15 July 2026. A ZIP code is a set of delivery routes, not an area; the point shown is a record coordinate, not a centre.