ZIP Codes of Iowa County, IA

Population & People
Population & People
Total Population
15,981
Household Income
Household Income
Median Income
$74,680
Housing
Housing
Total Housing Units
7,131
Business & Economy
Business & Economy
Total Businesses
462
Employment
Employment
Employment Rate
65.43%
Education
Education
Bachelor's Degree+
25.59%
Source: U.S. Census ACS 2024 5-Year Estimates · rolled up across the 12 ZIPs in this county.
Data Last Updated: July 1, 2026
ZIP Codes:12 ZIP Codes (9 Standard, 3 PO Box, 0 Unique) [See All]
Area Code:319
Timezone:Central (GMT -06:00)
Local Time:11:53:10 PM
Population:15,981 [See All]
FIPS:19095
Land Area:571 sq mi
Water Area:1 sq mi
Coordinates:41.6957, -92.0314
Quick Link:
https://www.zip-codes.com/county/ia-iowa.asp
Need Iowa data in your app? Look up ZIP, county, and city data with a single API call.
Try Free
Iowa's #47 most populous county
15,981 residents across 12 ZIPs — #47 of 99 Iowa counties.

Standout ZIPs in this County


Most Populous
Williamsburg · 4,582 people
28.7% of county total
Highest Income
Amana · $101,950 median
1.4× county average
Largest Land Area
Marengo · 133.9 sq mi
Spans the most ground
Fastest Growth
Amana · 14.0% (10-yr)
1,957 → 2,231 residents
Most Educated
Amana · 37.6% bachelor's+
601 of 1,597 adults 25+

Things worth knowing about Iowa County


15,981 residents live across 12 ZIPs covering 571 sq mi, served by 12 distinct USPS-recognized cities.

Population moved from 16,153 to 15,981 from 2014 to 2024 — a -1.1% change. 4 ZIPs gained residents, 8 lost.

The county's wealthiest ZIP 52203 (Amana, $101,950 median) and poorest ZIP 52316 (North English, $60,768) are 22.7 miles apart — a 1.7× income gap across local geography.

Median home values vary 2.8× across this county — from $106,500 in 52308 (Millersburg) to $297,100 in 52203 (Amana).

Density varies 129× across the county — from 8 people/sq mi in 52334 (South Amana) to 1,058 in 52308 (Millersburg).

Educational attainment ranges from 8.0% bachelor's+ in 52251 (Ladora) to 51.8% in 52220 (Conroy) — the breadth of educational profiles across the area.

Within Iowa, this is the #47 most populous of 99 counties and ranks #43 for median household income .

Weighted by population, the typical household earns about $73,185 across the county — reflecting what a typical resident sees, not a simple ZIP average.

25.6% of adults age 25+ hold a bachelor's degree or higher (2,862 of 11,183 reporting).

9 Standard delivery, 3 PO Box only, 0 single-entity Unique ZIPs serve this county.

Stories about Iowa County


Big & sparse

A frontier county — vast land area with only a few residents per square mile. Daily life looks very different here than in the country's denser counties.

Total area
571
square miles
Avg density
28.0
people per sq mi
Population
15,981
across 12 ZIPs
Marengo
133.9 sq mi
4,028 residents
Williamsburg
123.9 sq mi
4,582 residents
North English
78.7 sq mi
1,597 residents

All ZIP Codes in Iowa County


ZIPCityTypePopulationMedian IncomeArea (sq mi)10-yr Growth
52361WilliamsburgStandard4,582$60,992123.9-0.8%
52301MarengoStandard4,028$70,150133.911.4%
52203AmanaStandard2,231$101,95041.414.0%
52316North EnglishStandard1,597$60,76878.75.8%
52347VictorStandard1,386$78,48262.1-8.3%
52236HomesteadStandard564$87,95826.3-18.5%
52251LadoraStandard544$87,70840.8-6.0%
52325ParnellStandard477$75,71440.2-48.5%
52220ConroyPO Box1990.8-36.4%
52334South AmanaStandard18122.0-17.7%
52308MillersburgPO Box129$79,6880.1-19.9%
52307Middle AmanaPO Box63$43,3880.521.2%

Adjacent & Nearby Counties