Oldest ZIP codes in St. Clair County, IL
These are the 25 ZIP codes in St. Clair County with the highest median age, out of 28 with at least 1,000 residents. 62285 (Smithton, 48.2), 62204 (East Saint Louis, 46.8) and 62260 (Millstadt, 46.7) lead the list. There is no single "best" ZIP code in St. Clair County; the right one depends on who you want to reach, so the same ZIP codes are ranked several ways below.
Oldest ZIP codes in St. Clair County
| Rank | ZIP | Mailing city | Median age | Residents | Households | Residential mailboxes |
|---|---|---|---|---|---|---|
| 1 | 62285 | Smithton | 48.2 ±7.1 | 4,239 | 1,669 | — |
| 2 | 62204 | East Saint Louis | 46.8 ±11.0 | 4,055 | 1,710 | 1,625 |
| 3 | 62260 | Millstadt | 46.7 ±2.6 | 6,668 | 2,781 | 3,081 |
| 4 | 62255 | Lenzburg | 46.4 ±11.8 | 1,092 | 459 | — |
| 5 | 62243 | Freeburg | 44.5 ±4.5 | 6,418 | 2,393 | — |
| 6 | 62226 | Belleville | 43.6 ±1.5 | 28,255 | 11,919 | 13,116 |
| 7 | 62223 | Belleville | 43.6 ±2.0 | 16,269 | 7,096 | — |
| 8 | 62232 | Caseyville | 43.4 ±6.4 | 7,063 | 2,717 | 3,288 |
| 9 | 62203 | East Saint Louis | 43.0 ±5.4 | 5,465 | 1,843 | — |
| 10 | 62239 | Dupo | 43.0 ±7.2 | 4,232 | 1,763 | — |
| 11 | 62236 | Columbia | 42.3 ±2.3 | 14,154 | 5,485 | 5,732 |
| 12 | 62201 | East Saint Louis | 41.1 ±3.5 | 4,921 | 2,065 | — |
| 13 | 62208 | Fairview Heights | 40.8 ±2.1 | 16,821 | 7,336 | 7,500 |
| 14 | 62264 | New Athens | 40.7 ±4.3 | 3,097 | 1,315 | 1,282 |
| 15 | 62205 | East Saint Louis | 40.3 ±8.0 | 6,459 | 2,276 | — |
| 16 | 62258 | Mascoutah | 40.1 ±2.2 | 10,437 | 3,768 | 4,339 |
| 17 | 62265 | New Baden | 40.1 ±4.7 | 4,555 | 1,744 | — |
| 18 | 62220 | Belleville | 39.9 ±1.2 | 19,152 | 7,873 | 8,109 |
| 19 | 62293 | Trenton | 39.8 ±4.7 | 4,433 | 1,817 | — |
| 20 | 62257 | Marissa | 39.8 ±4.8 | 2,046 | 878 | — |
| 21 | 62234 | Collinsville | 39.2 ±2.6 | 31,648 | 13,843 | 14,250 |
| 22 | 62221 | Belleville | 38.5 ±1.6 | 29,875 | 12,151 | — |
| 23 | 62269 | O Fallon | 38.0 ±1.2 | 35,923 | 14,244 | — |
| 24 | 62207 | East Saint Louis | 35.3 ±5.3 | 6,984 | 2,593 | — |
| 25 | 62254 | Lebanon | 34.7 ±3.4 | 6,710 | 2,378 | 2,485 |
How we ranked them
Ranked by median age of all residents, highest first (ACS 5-year estimates, 2020–2024). ZIP codes need at least 1,000 residents to be ranked; 28 of 31 qualify.
Which of these to mail, and why
Older ZIP codes respond to health care, hearing and vision, Medicare plans, home safety, estate planning and services that come to the door.
The top five ZIP codes on this list hold 9,012 households. Open any of them on the route map to see each carrier route's own figures before you choose.
Open 62285 on the EDDM route map
More rankings
- Richest ZIP codes in St. Clair County
- ZIP codes with the highest home values in St. Clair County
- ZIP codes with the highest homeownership in St. Clair County
- ZIP codes with the most families with kids in St. Clair County
- ZIP codes with the most new movers in St. Clair County
- Youngest ZIP codes in St. Clair County
- Fastest-growing ZIP codes in St. Clair County
- All St. Clair County ZIP codes
Businesses that mail these ZIP codes
Map it and price it
EDDM guides
Frequently asked questions
- Which ZIP code in St. Clair County has the highest median age?
- 62285 (Smithton), at 48.2 (±7.1), among 28 ZIP codes with at least 1,000 residents.
- How is this ranking calculated?
- Ranked by median age of all residents, highest first (ACS 5-year estimates, 2020–2024).
- Why are some ZIP codes missing?
- ZIP codes with fewer than 1,000 residents are left out because their survey estimates swing too much to rank, and so are ZIP codes where the Census Bureau did not publish this figure.
This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.