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/LARGEST-AREA

Largest ZIP Codes in Iowa by Land Area

What this measures. Land area of the Census tabulation area, in square miles. Water is excluded. Source: Census Gazetteer, data release 2026-10-12.

# ZIP City County Land area
1 52537 Bloomfield Davis 338.45 sq mi
2 52101 Decorah Winneshiek 316.69 sq mi
3 51031 Le Mars Plymouth 234.14 sq mi
4 50841 Corning Adams 228.38 sq mi
5 52501 Ottumwa Wapello 225.33 sq mi
6 52531 Albia Monroe 223.01 sq mi
7 50833 Bedford Taylor 212.91 sq mi
8 50158 Marshalltown Marshall 212.15 sq mi
9 52641 Mount Pleasant Henry 211.79 sq mi
10 51632 Clarinda Page 211.21 sq mi
11 52136 Cresco Howard 210.42 sq mi
12 50213 Osceola Clarke 210.30 sq mi
13 50049 Chariton Lucas 208.62 sq mi
14 50801 Creston Union 207.20 sq mi
15 50025 Audubon Audubon 196.42 sq mi
16 50273 Winterset Madison 195.25 sq mi
17 50036 Boone Boone 191.68 sq mi
18 51334 Estherville Emmet 186.21 sq mi
19 50112 Grinnell Poweshiek 182.21 sq mi
20 52761 Muscatine Muscatine 178.21 sq mi
21 50461 Osage Mitchell 177.60 sq mi
22 51566 Red Oak Montgomery 176.41 sq mi
23 50616 Charles City Floyd 176.17 sq mi
24 52556 Fairfield Jefferson 175.54 sq mi
25 50060 Corydon Wayne 173.20 sq mi
26 50022 Atlantic Cass 172.55 sq mi
27 50115 Guthrie Center Guthrie 172.22 sq mi
28 51401 Carroll Carroll 168.53 sq mi
29 50138 Knoxville Marion 168.15 sq mi
30 52031 Bellevue Jackson 166.69 sq mi
31 50129 Jefferson Greene 165.35 sq mi
32 51001 Akron Plymouth 165.20 sq mi
33 51537 Harlan Shelby 163.79 sq mi
34 50125 Indianola Warren 162.39 sq mi
35 51246 Rock Rapids Lyon 161.11 sq mi
36 52172 Waukon Allamakee 159.90 sq mi
37 51442 Denison Crawford 159.57 sq mi
38 52060 Maquoketa Jackson 158.95 sq mi
39 50674 Sumner Bremer 158.93 sq mi
40 50208 Newton Jasper 158.51 sq mi
41 52577 Oskaloosa Mahaska 158.35 sq mi
42 51301 Spencer Clay 157.66 sq mi
43 52353 Washington Washington 157.44 sq mi
44 50595 Webster City Hamilton 153.52 sq mi
45 50659 New Hampton Chickasaw 152.99 sq mi
46 50501 Fort Dodge Webster 152.16 sq mi
47 52349 Vinton Benton 149.61 sq mi
48 50441 Hampton Franklin 148.35 sq mi
49 50401 Mason City Cerro Gordo 148.17 sq mi
50 51012 Cherokee Cherokee 147.75 sq mi

Showing the top 50 of 970 ZIP codes in Iowa that have this figure and meet the threshold above. 52537 ranks 1st at 338.45 sq mi, against 147.75 sq mi in 50th place.

Other rankings for Iowa

Cite this page

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

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