County ZIP codes · Illinois · FIPS 17189
Washington County, IL ZIP Codes
Washington County, Illinois has 13 ZIP codes (Census 2020 ZCTA-county file; GeoNames postal codes, October 2026), all residential. 10 of the residential ones lie mainly in Washington County and 3 mainly in a neighboring county; 7 cross the county line. Median household income ranges from $52,017 in 62801 (Centralia) to $104,063 in 62214 (Addieville) (Census Bureau, ACS 2020-2024).
- ACS2020-24
- Census2020
Where are the ZIP codes of Washington 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 $69,015 and $81,823.
They carry 13 postal town names.
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B19013).
All 13 residential ZIP codes in Washington County
10 ZIP codes lie mainly in Washington County; 3 more reach into it from a neighboring county and follow the first table.
| In this county | ||||||
|---|---|---|---|---|---|---|
| 62263 | Nashville | 4,819 | 33 | $72k | $165k | 99% |
| 62271 | Okawville | 1,873 | 30 | $83k | $164k | 100% |
| 62808 | Ashley | 1,602 | 21 | $69k | $147k | 68% |
| 62803 | Hoyleton | 1,132 | 20 | $82k | $119k | 100% |
| 62214 | Addieville | 1,048 | 19 | $104k | $169k | 100% |
| 62268 | Oakdale | 764 | 14 | $96k | $151k | 95% |
| 62848 | Irvington | 738 | 272 | $80k | $94k | 100% |
| 62877 | Richview | 437 | 14 | $84k | $126k | 94% |
| 62831 | Du Bois | 339 | 8 | $80k | $142k | 77% |
| 62876 | Radom | 146 | 53 | $56k | $105k | 100% |
Partly in Washington County
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?
8 ZIP codes of Washington County extend into another county. A ZIP code follows mail routes, not county borders.
| ZIP | In Washington | Elsewhere |
|---|---|---|
| 62801 | 16% | Marion County 37%; Clinton County 33%; Jefferson County 14% |
| 62263 | 99% | |
| 62237 | 26% | Perry County 49%; Randolph County 25% |
| 62257 | 36% | St. Clair County 57%; Randolph County 7% |
| 62808 | 68% | Jefferson County 32% |
| 62268 | 95% | Perry County 5% |
| 62877 | 94% | Jefferson County 6% |
| 62831 | 77% | Perry County 23% |
Source: U.S. Census Bureau, 2020 ZCTA-county relationship file (shares of land area).
Which first three digits do Washington County's ZIP codes use?
The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. Washington County's ZIP codes use 2 prefixes: 622 and 628.
Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.