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/HIGHEST-DENSITY

Most Densely Populated ZIP Codes in Iowa

What this measures. People per square mile of land area. Source: Census American Community Survey and Gazetteer, data release 2026-10-12.

# ZIP City County People per sq mi
1 52344 Troy Mills Linn 7,444
2 50013 Ames Story 6,600
3 52242 Iowa City Johnson 6,548
4 50311 Des Moines Polk 5,711
5 50012 Ames Story 5,561
6 50316 Des Moines Polk 4,685
7 52801 Davenport Scott 4,620
8 52803 Davenport Scott 4,425
9 50314 Des Moines Polk 4,228
10 50310 Des Moines Polk 3,880
11 50309 Des Moines Polk 3,725
12 50324 Windsor Heights Polk 3,663
13 50315 Des Moines Polk 3,381
14 52402 Cedar Rapids Linn 3,137
15 51104 Sioux City Woodbury 3,103
16 50322 Urbandale Polk 2,950
17 50312 Des Moines Polk 2,807
18 52245 Iowa City Johnson 2,722
19 52557 Fairfield Jefferson 2,566
20 50325 Clive Polk 2,462
21 50023 Ankeny Polk 2,227
22 50702 Waterloo Black Hawk 2,136
23 50634 Gilbertville Black Hawk 2,126
24 51510 Carter Lake Pottawattamie 2,100
25 50427 Chapin Franklin 2,015
26 52401 Cedar Rapids Linn 1,833
27 52233 Hiawatha Linn 1,789
28 52405 Cedar Rapids Linn 1,771
29 51105 Sioux City Woodbury 1,750
30 50265 West Des Moines Polk 1,736
31 52241 Coralville Johnson 1,721
32 50323 Urbandale Dallas 1,706
33 52030 Andrew Jackson 1,706
34 50266 West Des Moines Dallas 1,682
35 51578 Westphalia Shelby 1,657
36 50032 Berwick Polk 1,656
37 50317 Des Moines Polk 1,653
38 52001 Dubuque Dubuque 1,650
39 52722 Bettendorf Scott 1,568
40 50160 Martensdale Warren 1,546
41 50529 Dakota City Humboldt 1,483
42 50673 Stout Grundy 1,479
43 50320 Des Moines Polk 1,477
44 50163 Melcher Dallas Marion 1,448
45 51501 Council Bluffs Pottawattamie 1,446
46 51103 Sioux City Woodbury 1,400
47 52737 Columbus City Louisa 1,346
48 52246 Iowa City Johnson 1,335
49 50592 Truesdale Buena Vista 1,281
50 50021 Ankeny Polk 1,258

Showing the top 50 of 970 ZIP codes in Iowa that have this figure . 52344 ranks 1st at 7,444, against 1,258 in 50th place.

Other rankings for Iowa

Cite this page

zipcodes.pro. “Most Densely Populated ZIP Codes in Iowa.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/rankings/ia/highest-density

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