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/IL/COUNTY/WARREN

Warren County, IL ZIP codes

There are 8 ZIP codes in Warren County, IL, in 8 towns, from 61417 to 61478. The largest are 61462 (Monmouth), 61473 (Roseville) and 61447 (Kirkwood). 2 more cross into it from neighbouring counties: 61415 and 61412.

The county seat is Monmouth.

ZIP codes
8
Partly in it
2 more
Towns
8
County seat
Monmouth
County FIPS
17187
Population
16,447
Median household income
$67,385
Land area
542 sq mi

Warren County ZIP codes by town

Monmouth (county seat)
61462

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 Warren County

These ZIP codes lie mostly in a neighbouring county but each cover a twentieth or more of Warren County.

Map of Warren County ZIP codes

6141761423614356144761453614626147361478

The ZIP codes of Warren 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.

Warren County in numbers

About 16,447 people live in Warren County, in 6,787 households, the 65th most populous of Illinois's 102 counties. The median household income is $67,385 a year, 19% below the Illinois median of $83,390 (US: $80,734). The median owner-occupied home is valued at $105,000 (60% below the Illinois median), and median gross rent is $788 a month. The median age is 38.5; 22.0% of adults 25 and over hold a bachelor's degree or higher (37.8% across Illinois); the average commute takes 19 minutes.

Population16,447Warren16,447
Households6,787Warren6,787
Median age38.5Warren38.5Illinois39.0US 38.9
Median household income$67,385Warren$67,385Illinois$83,390US $80,734
Median home value$105,000Warren$105,000Illinois$263,300US $332,700
Median gross rent$788Warren$788Illinois$1,274US $1,413
Bachelor's degree or higher22.0%Warren22.0%Illinois37.8%US 35.7%
Mean commute18.8 minWarren18.8 minIllinois27.8 minUS 26.4 min
Population density30 / sq miWarren30 / 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 Warren County

Largest towns in Warren County
TownZIP codesPopulation
Monmouth 1 8,581
Roseville 1 823
Kirkwood 1 754
Smithshire 1 420
Little York 1 379
Cameron 1 280
Gerlaw 1 271
Berwick 1 182

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 Warren County.

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

Every ZIP code in Warren County, with figures

ZIP codes in Warren County
ZIP City Type Population Median income Median home
61417 Berwick , IL Standard 182 $105,724 $107,200
61423 Cameron , IL Standard 638 $78,594 $123,500
61435 Gerlaw , IL Standard 271 — —
61447 Kirkwood , IL Standard 1,020 $82,583 $95,900
61453 Little York , IL Standard 677 $58,281 $87,500
61462 Monmouth , IL Standard 10,458 $64,113 $102,900
61473 Roseville , IL Standard 1,279 $60,833 $108,100
61478 Smithshire , IL Standard 420 $75,625 $103,600

Cite this page

zipcodes.pro. “Warren County ZIP codes.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/state/il/county/warren

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