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 — RANKINGS/IA/SMALLEST-AREA

Smallest ZIP Codes in Iowa by Land Area

What this measures. Land area of the Census tabulation area, smallest first. These are almost always dense urban ZIP codes covering a few city blocks. Source: Census Gazetteer, data release 2026-10-12.

# ZIP City County Land area
1 52344 Troy Mills Linn 0.01 sq mi
2 50649 Kesley Butler 0.03 sq mi
3 51045 Oyens Plymouth 0.07 sq mi
4 50427 Chapin Franklin 0.07 sq mi
5 51578 Westphalia Shelby 0.07 sq mi
6 52312 Morley Jones 0.07 sq mi
7 51340 Fostoria Clay 0.12 sq mi
8 52308 Millersburg Iowa 0.12 sq mi
9 50241 Saint Marys Warren 0.14 sq mi
10 50041 Bradford Franklin 0.14 sq mi
11 50620 Colwell Floyd 0.15 sq mi
12 50592 Truesdale Buena Vista 0.15 sq mi
13 50657 Morrison Grundy 0.15 sq mi
14 50673 Stout Grundy 0.17 sq mi
15 50319 Des Moines Polk 0.18 sq mi
16 50631 Frederika Bremer 0.19 sq mi
17 50593 Varina Pocahontas 0.19 sq mi
18 52562 Hayesville Keokuk 0.19 sq mi
19 50255 Thornburg Keokuk 0.19 sq mi
20 50033 Bevington Madison 0.20 sq mi
21 52548 Chillicothe Wapello 0.20 sq mi
22 52631 Houghton Lee 0.20 sq mi
23 50031 Beaver Boone 0.21 sq mi
24 50608 Austinville Butler 0.22 sq mi
25 50831 Arispe Union 0.22 sq mi
26 50847 Grant Montgomery 0.23 sq mi
27 51651 Shambaugh Page 0.23 sq mi
28 52759 Montpelier Muscatine 0.24 sq mi
29 52737 Columbus City Louisa 0.24 sq mi
30 52030 Andrew Jackson 0.25 sq mi
31 50078 Ferguson Marshall 0.26 sq mi
32 50842 Cromwell Union 0.26 sq mi
33 52166 Saint Lucas Fayette 0.26 sq mi
34 52568 Martinsburg Keokuk 0.26 sq mi
35 51009 Calumet O'Brien 0.27 sq mi
36 52557 Fairfield Jefferson 0.27 sq mi
37 51656 Yorktown Page 0.27 sq mi
38 51008 Brunsville Plymouth 0.28 sq mi
39 52647 Olds Henry 0.28 sq mi
40 52348 Vining Tama 0.29 sq mi
41 52774 Welton Clinton 0.30 sq mi
42 51432 Aspinwall Crawford 0.31 sq mi
43 51341 Gillett Grove Clay 0.34 sq mi
44 50012 Ames Story 0.34 sq mi
45 50426 Carpenter Mitchell 0.35 sq mi
46 50634 Gilbertville Black Hawk 0.36 sq mi
47 50272 Williamson Lucas 0.36 sq mi
48 50160 Martensdale Warren 0.37 sq mi
49 50652 Lincoln Tama 0.37 sq mi
50 51451 Lanesboro Carroll 0.38 sq mi

Showing the top 50 of 970 ZIP codes in Iowa that have this figure and meet the threshold above. 52344 ranks 1st at 0.01 sq mi, against 0.38 sq mi in 50th place.

Other rankings for Iowa

Cite this page

zipcodes.pro. “Smallest ZIP Codes in Iowa by Land Area.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/rankings/ia/smallest-area

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