| ZIP Codes: | 19 ZIP Codes (14 Standard, 5 PO Box, 0 Unique) [See All] |
| Area Code: | 636 |
| Timezone: | Central (GMT -06:00) |
| Local Time: | 2:12:43 PM |
| Population: | 200,118 [See All] |
| FIPS: | 29099 |
| CBSA: | St. Louis, MO-IL |
| Land Area: | 645 sq mi |
| Water Area: | 7 sq mi |
| Coordinates: | 38.2892, -90.5034 |
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200,118 residents live across 19 ZIPs covering 645 sq mi, served by 19 distinct USPS-recognized cities.
Population moved from 195,236 to 200,118 from 2014 to 2024 — a +2.5% change. 9 ZIPs gained residents, 6 lost (and 1 held flat).
The county's wealthiest ZIP 63012 (Barnhart, $96,099 median) and poorest ZIP 63070 (Pevely, $65,211) are 3.7 miles apart — a 1.5× income gap across local geography.
Median home values vary 1.6× across this county — from $185,900 in 63020 (De Soto) to $288,200 in 63050 (Hillsboro).
Density varies 20× across the county — from 77 people/sq mi in 63023 (Dittmer) to 1,583 in 63010 (Arnold).
Educational attainment ranges from 15.1% bachelor's+ in 63020 (De Soto) to 28.9% in 63049 (High Ridge) — the breadth of educational profiles across the area.
Within Missouri, this is the #7 most populous of 116 counties and ranks #10 for median household income .
Weighted by population, the typical household earns about $83,080 across the county — reflecting what a typical resident sees, not a simple ZIP average.
23.3% of adults age 25+ hold a bachelor's degree or higher (32,548 of 139,698 reporting).
14 Standard delivery, 5 PO Box only, 0 single-entity Unique ZIPs serve this county.
| ZIP | City | Type | Population | Median Income | Area (sq mi) | 10-yr Growth |
|---|---|---|---|---|---|---|
| 63010 | Arnold | Standard | 34,478 | $79,784 | 21.8 | -5.0% |
| 63052 | Imperial | Standard | 28,712 | $92,922 | 33.8 | 11.1% |
| 63028 | Festus | Standard | 28,457 | $79,737 | 127.1 | 6.5% |
| 63020 | De Soto | Standard | 20,166 | $70,824 | 143.2 | 0.7% |
| 63050 | Hillsboro | Standard | 18,744 | $87,371 | 92.8 | 20.9% |
| 63049 | High Ridge | Standard | 16,592 | $92,333 | 24.8 | 2.5% |
| 63051 | House Springs | Standard | 13,436 | $79,940 | 44.0 | -6.9% |
| 63012 | Barnhart | Standard | 10,314 | $96,099 | 24.7 | -3.2% |
| 63070 | Pevely | Standard | 8,428 | $65,211 | 15.7 | 7.4% |
| 63016 | Cedar Hill | Standard | 6,459 | $86,359 | 28.0 | -15.0% |
| 63023 | Dittmer | Standard | 5,002 | $79,583 | 64.6 | -11.7% |
| 63019 | Crystal City | Standard | 4,489 | $72,569 | 3.6 | 0.5% |
| 63048 | Herculaneum | Standard | 4,228 | $92,109 | 4.4 | 18.7% |
| 63030 | Fletcher | Standard | 557 | $91,042 | 16.9 | 63.8% |
| 63053 | Kimmswick | PO Box | 56 | $61,250 | 0.0 | -37.8% |
| 63047 | Hematite | PO Box | 0 | — | 0.0 | — |
| 63057 | Liguori | PO Box | — | — | 0.0 | — |
| 63065 | Mapaville | PO Box | — | — | 0.0 | — |
| 63066 | Morse Mill | PO Box | — | — | 0.0 | — |