| ZIP Codes: | 6 ZIP Codes (6 Standard, 0 PO Box, 0 Unique) [See All] |
| Area Codes: | 319 / 641 |
| Timezone: | Central (GMT -06:00) |
| Local Time: | 2:11:53 PM |
| Population: | 15,441 [See All] |
| FIPS: | 19101 |
| Land Area: | 380 sq mi |
| Water Area: | 1 sq mi |
| Coordinates: | 41.0160, -92.0025 |
| Quick Link: |
15,441 residents live across 6 ZIPs covering 380 sq mi, served by 5 distinct USPS-recognized cities.
Population moved from 16,436 to 15,441 from 2014 to 2024 — a -6.1% change. 3 ZIPs gained residents, 3 lost.
The county's wealthiest ZIP 52567 (Libertyville, $81,985 median) and poorest ZIP 52580 (Packwood, $53,368) are 12.9 miles apart — a 1.5× income gap across local geography.
Median home values vary 1.5× across this county — from $116,200 in 52580 (Packwood) to $175,000 in 52635 (Lockridge).
Density varies 5× across the county — from 14 people/sq mi in 52533 (Batavia) to 64 in 52556 (Fairfield).
Educational attainment ranges from 15.3% bachelor's+ in 52567 (Libertyville) to 83.6% in 52557 (Fairfield) — the breadth of educational profiles across the area.
Within Iowa, this is the #48 most populous of 99 counties and ranks #85 for median household income .
Weighted by population, the typical household earns about $61,055 across the county — reflecting what a typical resident sees, not a simple ZIP average.
43.6% of adults age 25+ hold a bachelor's degree or higher (5,028 of 11,534 reporting). The most-educated ZIPs cluster around Fairfield.
6 Standard delivery, 0 PO Box only, 0 single-entity Unique ZIPs serve this county.
One ZIP holds the majority of this county's population — a sign of a county built around a single city or town.
Jefferson County lost 6.1% of residents between 2014 and 2024. ZIPs that shed the largest share:
| ZIP | City | Type | Population | Median Income | Area (sq mi) | 10-yr Growth |
|---|---|---|---|---|---|---|
| 52556 | Fairfield | Standard | 11,448 | $59,243 | 178.4 | -10.9% |
| 52533 | Batavia | Standard | 1,201 | $62,799 | 85.1 | -18.0% |
| 52635 | Lockridge | Standard | 890 | $76,250 | 47.9 | 0.7% |
| 52580 | Packwood | Standard | 711 | $53,368 | 38.1 | 49.4% |
| 52557 | Fairfield | Standard | 685 | — | 0.0 | 851.4% |
| 52567 | Libertyville | Standard | 506 | $81,985 | 30.2 | -26.5% |