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 — STATE/IA/COUNTY/FREMONT

Fremont County, IA ZIP codes

There are 9 ZIP codes in Fremont County, IA, in 9 towns, from 51639 to 51654. The largest are 51652 (Sidney), 51640 (Hamburg) and 51653 (Tabor). 1 more crosses into it from a neighbouring county: 51601.

The county seat is Sidney.

ZIP codes
9
Partly in it
1 more
Towns
9
County seat
Sidney
County FIPS
19071
State
Iowa
Population
6,514
Median household income
$71,621
Land area
511 sq mi

Fremont County ZIP codes by town

Sidney (county seat)
51652

Each ZIP code is listed under the county most of its land lies in and the town the Postal Service names it for; a ZIP code's own page shows exactly how it is split.

ZIP codes partly in Fremont County

This ZIP code lies mostly in a neighbouring county but covers a twentieth or more of Fremont County.

Map of Fremont County ZIP codes

516395164051645516485164951650516525165351654

The ZIP codes of Fremont County, shaded. Outlines are Census ZIP Code Tabulation Areas (2020), which approximate the mail routes; PO-box and single-address codes have no area and are not drawn. Click any area to open its ZIP code.

Fremont County in numbers

About 6,514 people live in Fremont County, in 2,823 households, the 94th most populous of Iowa's 99 counties. The median household income is $71,621 a year, 5% below the Iowa median of $75,059 (US: $80,734). The median owner-occupied home is valued at $154,400 (26% below the Iowa median), and median gross rent is $746 a month. The median age is 46.8; 20.8% of adults 25 and over hold a bachelor's degree or higher (31.4% across Iowa); the average commute takes 22 minutes.

Population6,514Fremont6,514
Households2,823Fremont2,823
Median age46.8Fremont46.8Iowa38.6US 38.9
Median household income$71,621Fremont$71,621Iowa$75,059US $80,734
Median home value$154,400Fremont$154,400Iowa$208,000US $332,700
Median gross rent$746Fremont$746Iowa$972US $1,413
Bachelor's degree or higher20.8%Fremont20.8%Iowa31.4%US 35.7%
Mean commute22.3 minFremont22.3 minIowa19.8 minUS 26.4 min
Population density13 / sq miFremont13 / sq mi

U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates. Survey estimates carry margins of error, wider for small places. Sources and methods.

Largest towns in Fremont County

Largest towns in Fremont County
TownZIP codesPopulation
Sidney 1 955
Hamburg 1 927
Tabor 1 877
Farragut 1 413
Randolph 1 235
Thurman 1 217
Riverton 1 188
Percival 1 105
Imogene 1 49

Population of the census place of that name where there is one, otherwise of the ZIP codes the Postal Service addresses by it. A town's ZIP codes can reach past the county line.

Neighbouring counties

Counties that share a ZIP code with Fremont County.

Not sure you are in Fremont County? What county am I in? answers from your location, near a county line included.

Every ZIP code in Fremont County, with figures

ZIP codes in Fremont County
ZIP City Type Population Median income Median home
51639 Farragut , IA Standard 919 $84,688 $157,300
51640 Hamburg , IA Standard 1,381 $65,385 $122,900
51645 Imogene , IA Standard 419 $217,898 —
51648 Percival , IA Standard 257 $59,766 $164,000
51649 Randolph , IA Standard 346 $58,333 $101,400
51650 Riverton , IA Standard 197 $49,063 $54,200
51652 Sidney , IA Standard 1,569 $82,200 $134,800
51653 Tabor , IA Standard 1,446 $71,319 $230,200
51654 Thurman , IA Standard 325 $90,188 $231,800

Cite this page

zipcodes.pro. “Fremont County ZIP codes.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/state/ia/county/fremont

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