Find the last 4 digits (ZIP+4) for an address in 51040

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ZIP Code 51040 – Onawa, IA

Onawa, Iowa · Monona County · Central time

ZIP code51040
CityOnawa
StateIowa
CountyMonona County
Population3,500
Time zoneCentral · local time
ZIP typeStandard (has a Census ZCTA area)
Land area129.51 sq mi
Center (lat, long)42.0325, -96.0687

Area codes in this area

712

These are the area codes that most often serve ZIP 51040 (including overlays). The exact area code depends on the phone number — landlines, mobiles and overlays can differ even on the same street.

Map

Nearby ZIP codes

51010 Castana · 8.1 mi51523 Blencoe · 8.1 mi51063 Whiting · 9.3 mi68020 Decatur · 10.9 mi51558 Moorhead · 12.6 mi51545 Little Sioux · 12.8 mi51051 Rodney · 13.1 mi51572 Soldier · 13.8 mi

About ZIP 51040

ZIP code 51040 is assigned to Onawa, Iowa. It lies in Monona County. Its Census area covers about 129.51 square miles of land. The closest neighboring ZIP is 51010 (Castana), about 8.1 miles away.

Every address in 51040 also has a 4-digit add-on code (ZIP+4) that points to a smaller delivery area. Use the box above to find it.

Sources: US Census Bureau (ZCTA, county relationship files), GeoNames (CC BY 4.0), NANPA via NumberResearch.org (CC BY 4.0). Map © OpenStreetMap contributors. ZIP areas are approximate. Population: U.S. Census Bureau, ACS 5-year estimates, 2024 (ZCTA). Data sources