Every ZIP code in the United States, with weather, radar, trivia and the numbers behind it. Five digits since 1963!

ZIP stands for Zone Improvement Plan. The codes went live on July 1, 1963.The lowest ZIP code is 00501 — the IRS in Holtsville, New York.The highest ZIP code is 99950, in Ketchikan, Alaska.Type 07734 into a calculator and turn it upside down: hELLO. It is Keansburg, New Jersey.12345 belongs to one company: General Electric in Schenectady, New York.The first digit is a region: 0 is New England and New Jersey, 9 is the West Coast, Alaska and Hawaii.Mr. ZIP, the cartoon mailman, was the mascot that sold the idea to America.ZIP+4 arrived in 1983 and can narrow a ZIP down to one side of one block.A ZIP code is a mail route, not a place: plenty of them cross county and even state lines.Play ZIP Hunt: guess the secret ZIP code of the day in six tries.
zipcodes.pro — STATE/IA/COUNTY/UNION

Union County, IA ZIP codes

Union County, IA has 6 ZIP codes, in 6 towns: 50801, 50830, 50254, 50861, 50831 and 50842. 2 more cross into it from neighbouring counties: 50851 and 50149.

The county seat is Creston.

ZIP codes
6
Partly in it
2 more
Towns
6
County seat
Creston
County FIPS
19175
State
Iowa
Population
11,993
Median household income
$57,772
Land area
424 sq mi

Union County ZIP codes by town

Creston (county seat)
50801

Each ZIP code is listed under the county most of its land lies in and the town the Postal Service names it for; a ZIP code's own page shows exactly how it is split.

ZIP codes partly in Union County

These ZIP codes lie mostly in a neighbouring county but each cover a twentieth or more of Union County.

Map of Union County ZIP codes

502545080150830508315084250861

The ZIP codes of Union County, shaded. Outlines are Census ZIP Code Tabulation Areas (2020), which approximate the mail routes; PO-box and single-address codes have no area and are not drawn. Click any area to open its ZIP code.

Union County in numbers

About 11,993 people live in Union County, in 5,116 households, the 63rd most populous of Iowa's 99 counties. The median household income is $57,772 a year, 23% below the Iowa median of $75,059 (US: $80,734). The median owner-occupied home is valued at $122,000 (41% below the Iowa median), and median gross rent is $721 a month. The median age is 40.5; 23.3% of adults 25 and over hold a bachelor's degree or higher (31.4% across Iowa); the average commute takes 16 minutes.

Population11,993Union11,993
Households5,116Union5,116
Median age40.5Union40.5Iowa38.6US 38.9
Median household income$57,772Union$57,772Iowa$75,059US $80,734
Median home value$122,000Union$122,000Iowa$208,000US $332,700
Median gross rent$721Union$721Iowa$972US $1,413
Bachelor's degree or higher23.3%Union23.3%Iowa31.4%US 35.7%
Mean commute15.8 minUnion15.8 minIowa19.8 minUS 26.4 min
Population density28 / sq miUnion28 / sq mi

U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates. Survey estimates carry margins of error, wider for small places. Sources and methods.

Largest towns in Union County

Largest towns in Union County
TownZIP codesPopulation
Creston 1 7,435
Afton 1 817
Shannon City 1 115
Cromwell 1 103
Arispe 1 78
Thayer 1 45

Population of the census place of that name where there is one, otherwise of the ZIP codes the Postal Service addresses by it. A town's ZIP codes can reach past the county line.

Neighbouring counties

Counties that share a ZIP code with Union County.

Not sure you are in Union County? What county am I in? answers from your location, near a county line included.

Every ZIP code in Union County, with figures

ZIP codes in Union County
ZIP City Type Population Median income Median home
50254 Thayer , IA Standard 296 $64,211 $175,000
50801 Creston , IA Standard 9,034 $58,015 $124,900
50830 Afton , IA Standard 1,846 $61,094 $113,300
50831 Arispe , IA Standard 22 $95,625 —
50842 Cromwell , IA Standard 99 $59,583 $104,700
50861 Shannon City , IA Standard 311 $63,125 —

Cite this page

zipcodes.pro. “Union County ZIP codes.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/state/ia/county/union

Underlying data is public domain or openly licensed — sources, vintages and licences.