Which ZIP code in St. Clair County has the fastest population growth?

62240 (East Carondelet), at 19.2%, among 28 ZIP codes with at least 1,000 residents.

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.

Fastest-growing ZIP codes in St. Clair County, IL

These are the 25 ZIP codes in St. Clair County with the fastest population growth, out of 28 with at least 1,000 residents. 62240 (East Carondelet, 19.2%), 62269 (O Fallon, 13.8%) and 62265 (New Baden, 11.9%) 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.

Fastest-growing ZIP codes in St. Clair County

Rank	ZIP	Mailing city	Population change	Residents	Households	Residential mailboxes
1	62240	East Carondelet	19.2%	1,796	535	675
2	62269	O Fallon	13.8%	35,923	14,244	—
3	62265	New Baden	11.9%	4,555	1,744	—
4	62243	Freeburg	11.5%	6,418	2,393	—
5	62258	Mascoutah	10.0%	10,437	3,768	4,339
6	62254	Lebanon	8.4%	6,710	2,378	2,485
7	62220	Belleville	8.1%	19,152	7,873	8,109
8	62232	Caseyville	3.4%	7,063	2,717	3,288
9	62208	Fairview Heights	1.7%	16,821	7,336	7,500
10	62223	Belleville	1.7%	16,269	7,096	—
11	62236	Columbia	0.6%	14,154	5,485	5,732
12	62225	Scott Air Force Base	0.6%	5,242	1,509	—
13	62293	Trenton	-0.1%	4,433	1,817	—
14	62221	Belleville	-1.4%	29,875	12,151	—
15	62226	Belleville	-2.3%	28,255	11,919	13,116
16	62234	Collinsville	-2.5%	31,648	13,843	14,250
17	62285	Smithton	-6.0%	4,239	1,669	—
18	62239	Dupo	-7.9%	4,232	1,763	—
19	62260	Millstadt	-11.5%	6,668	2,781	3,081
20	62206	East Saint Louis	-13.9%	12,959	4,620	4,484
21	62257	Marissa	-15.3%	2,046	878	—
22	62205	East Saint Louis	-17.0%	6,459	2,276	—
23	62264	New Athens	-17.5%	3,097	1,315	1,282
24	62255	Lenzburg	-18.0%	1,092	459	—
25	62207	East Saint Louis	-23.2%	6,984	2,593	—

How we ranked them

Ranked by the change in ACS population estimates between the 2015–2019 and 2020–2024 releases. Both are 5-year averages, and ZIP code areas were redrawn for 2020, so a large change can partly reflect a boundary change. Both periods must have at least 1,000 residents. ZIP codes need at least 1,000 residents to be ranked; 28 of 31 qualify.

Which of these to mail, and why

Growing ZIP codes add households every year, which means new homes, new routes and customers without a go-to provider yet. Check the route map: new subdivisions can appear as new carrier routes.

The top five ZIP codes on this list hold 22,684 households. Open any of them on the route map to see each carrier route's own figures before you choose.

Open 62240 on the EDDM route map

More rankings

Businesses that mail these ZIP codes

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EDDM guides

Frequently asked questions

Which ZIP code in St. Clair County has the fastest population growth?: 62240 (East Carondelet), at 19.2%, among 28 ZIP codes with at least 1,000 residents.
How is this ranking calculated?: Ranked by the change in ACS population estimates between the 2015–2019 and 2020–2024 releases. Both are 5-year averages, and ZIP code areas were redrawn for 2020, so a large change can partly reflect a boundary change. Both periods must have at least 1,000 residents.
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.