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 — PREFIX/538

ZIP codes starting with 538

ZIP codes
22
States
WI
Largest city
Platteville, WI
Population
60,143

The first three digits of a ZIP code identify a sectional center facility — the postal processing plant that sorts mail for the area. It is a mail-routing grouping, not an administrative boundary.

Every ZIP code in 538xx

ZIP codes starting with 538
ZIP City Type Population Median income Median home
53801 Bagley , WI Standard 998 $65,357 $135,100
53802 Beetown , WI Standard 132 $80,417 $169,600
53803 Benton , WI Standard 1,386 $79,545 $163,700
53804 Bloomington , WI Standard 1,275 $82,917 $165,800
53805 Boscobel , WI Standard 5,554 $60,870 $164,100
53806 Cassville , WI Standard 1,514 $64,076 $164,600
53807 Cuba City , WI Standard 4,209 $77,887 $225,500
53808 Dickeyville , WI Standard 905 $70,913 $193,400
53809 Fennimore , WI Standard 4,748 $65,568 $192,500
53810 Glen Haven , WI Standard 389 $75,500 $167,500
53811 Hazel Green , WI Standard 3,093 $82,769 $224,700
53812 Kieler , WI Standard 254 $80,833 $199,200
53813 Lancaster , WI Standard 6,222 $84,004 $220,400
53816 Mount Hope , WI Standard 856 $71,250 $201,100
53817 Patch Grove , WI Standard 227 $48,958 $150,300
53818 Platteville , WI Standard 16,024 $55,567 $236,700
53820 Potosi , WI Standard 2,467 $77,083 $201,900
53821 Prairie Du Chien , WI Standard 7,780 $60,647 $168,300
53824 Sinsinawa , WI No street area — — —
53825 Stitzer , WI Standard 358 $102,500 $170,800
53826 Wauzeka , WI Standard 1,323 $73,438 $173,200
53827 Woodman , WI Standard 429 $81,607 $163,200

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zipcodes.pro. “ZIP codes starting with 538.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/prefix/538

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