ZIP Code 51040

ZIP code 51040 is classified by USPS as a standard delivery area and covers roughly 394.9 square miles in Onawa, Monona County, Iowa. The area is home to 3,712 residents, producing a population density of 9 people per square mile, and falls within the Chicago time zone. These USPS and Census boundary values drive every downstream statistic on this page, including the benchmarks that compare 51040 against Iowa and the nation.

On the economic side, the median household income for ZIP 51040 sits at $71,179 (7% below the Iowa average), while per-capita income is $33,598. The poverty rate stands at 14.2% and the unemployment rate at 1.2%. On housing, the median home value is $151,600 (14% below the state average) with median rent at $947 per month, and 75.3% of occupied units are owner-occupied, a direct signal of whether 51040 behaves more like a homeowner neighborhood or a renter-heavy ZIP.

Education and household profile round out the picture: 19.9% of adults hold a bachelor's degree or higher, the median age is 37.6, and the average commute is 18 minutes. We also surface 2 nearby ZIP codes within roughly 10 miles and 6 additional ZIPs sharing Monona County, so you can benchmark 51040 against its immediate geography rather than a national average alone. Every figure is sourced from the U.S. Census Bureau American Community Survey 5-Year Estimates, HUD Fair Market Rents, and FHFA Home Price Index data, no estimates, no proprietary scoring. Verify with HUD →