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/ID/OLDEST

ZIP Codes With the Oldest Population in Idaho

What this measures. Median age of residents, ACS 5-year estimate. Source: Census American Community Survey, data release 2026-10-12.

# ZIP City County Median age
1 83666 Placerville Boise 72.5
2 83433 Macks Inn Fremont 72.2
3 83463 Gibbonsville Lemhi 71.7
4 83812 Clarkia Shoshone 71.5
5 83243 Holbrook Oneida 71.0
6 83466 North Fork Lemhi 70.2
7 83469 Shoup Lemhi 70.1
8 83874 Murray Shoshone 69.3
9 83636 Letha Gem 69.0
10 83429 Island Park Fremont 68.2
11 83278 Stanley Custer 68.0
12 83554 White Bird Idaho 67.9
13 83637 Lowman Boise 67.5
14 83808 Calder Shoshone 67.5
15 83465 Lemhi Lemhi 66.5
16 83547 Pollock Idaho 66.5
17 83826 Eastport Boundary 66.3
18 83253 May Lemhi 66.0
19 83285 Wayan Bonneville 64.5
20 83643 Mesa Adams 64.0
21 83810 Cataldo Kootenai 64.0
22 83549 Riggins Idaho 63.9
23 83287 Fish Haven Bear Lake 63.0
24 83446 Spencer Clark 62.6
25 83657 Ola Gem 62.6
26 83841 Laclede Bonner 62.5
27 83842 Medimont Kootenai 62.5
28 83421 Chester Fremont 62.4
29 83525 Elk City Idaho 62.1
30 83546 Pierce Clearwater 62.0
31 83612 Council Adams 62.0
32 83627 Hammett Owyhee 60.9
33 83533 Greencreek Idaho 60.8
34 83803 Bayview Bonner 60.7
35 83251 Mackay Custer 60.6
36 83541 Lenore Nez Perce 60.5
37 83552 Stites Idaho 60.5
38 83833 Harrison Kootenai 59.8
39 83809 Careywood Bonner 59.7
40 83545 Peck Nez Perce 59.5
41 83836 Hope Bonner 59.5
42 83827 Elk River Clearwater 59.4
43 83622 Garden Valley Boise 59.2
44 83848 Nordman Bonner 59.2
45 83553 Weippe Clearwater 59.0
46 83281 Swanlake Bannock 58.8
47 83539 Kooskia Idaho 58.8
48 83821 Coolin Bonner 58.7
49 83340 Ketchum Blaine 58.5
50 83520 Ahsahka Clearwater 58.2

Showing the top 50 of 272 ZIP codes in Idaho that have this figure . 83666 ranks 1st at 72.5, against 58.2 in 50th place.

Other rankings for Idaho

Cite this page

zipcodes.pro. “ZIP Codes With the Oldest Population in Idaho.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/rankings/id/oldest

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