County ZIP codes · Kentucky · FIPS 21227
Warren County, KY ZIP Codes
Warren County, Kentucky has 11 ZIP codes (Census 2020 ZCTA-county file; GeoNames postal codes, October 2026): 9 residential and 2 for PO boxes or a single organization. 8 of the residential ones lie mainly in Warren County and 1 mainly in a neighboring county; 7 cross the county line. Median household income ranges from $48,217 in 42101 (Bowling Green) to $113,705 in 42122 (Alvaton) (Census Bureau, ACS 2020-2024).
- ACS2020-24
- Census2020
Where are the ZIP codes of Warren County?
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).
How different are its ZIP codes?
The middle half of its ranked ZIP codes (1,000+ people living in households) report median household incomes between $66,815 and $80,704.
They carry 7 postal town names: Bowling Green, Smiths Grove, Auburn, Alvaton, Rockfield, Woodburn, Oakland.
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B19013).
All 9 residential ZIP codes in Warren County
8 ZIP codes lie mainly in Warren County; 1 more reaches into it from a neighboring county and follows the first table.
| In this county | ||||||
|---|---|---|---|---|---|---|
| 42101 | Bowling Green | 65,421 | 233 | $48k | $207k | 89% |
| 42104 | Bowling Green | 42,076 | 725 | $75k | $306k | 91% |
| 42103 | Bowling Green | 21,911 | 311 | $88k | $331k | 100% |
| 42171 | Smiths Grove | 6,723 | 65 | $70k | $188k | 48% |
| 42122 | Alvaton | 5,513 | 146 | $114k | $297k | 95% |
| 42274 | Rockfield | 2,157 | 53 | $81k | $182k | 89% |
| 42170 | Woodburn | 1,938 | 63 | $96k | $292k | 51% |
| 42159 | Oakland | 1,699 | 54 | $67k | $264k | 100% |
Partly in Warren County
| In this county | ||||||
|---|---|---|---|---|---|---|
| 42206 | Auburn | 5,897 | 52 | $67k | $168k | 1% |
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; county shares by land area (Census 2020 ZCTA-county relationship file).
Which ZIP codes cross the county line?
7 ZIP codes of Warren County extend into another county. A ZIP code follows mail routes, not county borders.
| ZIP | In Warren | Elsewhere |
|---|---|---|
| 42101 | 89% | Edmonson County 8%; Butler County 3% |
| 42104 | 91% | Simpson County 9% |
| 42171 | 48% | Edmonson County 28%; Barren County 25% |
| 42206 | 1% | Logan County 86%; Simpson County 13% |
| 42122 | 95% | Allen County 5% |
| 42274 | 89% | Logan County 11% |
| 42170 | 51% | Simpson County 49% |
Source: U.S. Census Bureau, 2020 ZCTA-county relationship file (shares of land area).
PO Box and single-organization ZIP codes
| ZIP | Postal name |
|---|---|
| 42102 | Bowling Green |
| 42128 | Drake |
Source: GeoNames postal codes (CC BY 4.0).
Which first three digits do Warren County's ZIP codes use?
The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. Warren County's ZIP codes use 2 prefixes: 421 and 422.
Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.