Washington County is a county in Iowa, United States, in the southeast part of the state, part of the Iowa City metropolitan area. It had a population of 22,565 at the 2020 census and covers 571 square miles (1,480 km2), of which 569 square miles are land and 2.1 square miles are water, centred near 41°20′N 91°43′W.
Washington is the county seat and its postal code is 52353. The county has 6 incorporated cities, no separate “towns” (Iowa law incorporates all municipalities as cities regardless of size), and a dozen-plus small unincorporated communities and mobile-home parks, grouped across 15 civil townships. Central time zone (UTC−6, UTC−5 during daylight saving).
Towns & Villages in Washington County
Six places carry city incorporation; the rest are unincorporated communities, rural crossroads, or manufactured-home parks with no municipal government of their own. Population figures below are the 2020 census count where the place has one on record.
| Place | Type | Township | Pop. | ZIP |
|---|---|---|---|---|
| Washington | City · seat | Washington | 7,352 | 52353 |
| Kalona | City | — | 2,630 | 52247 |
| Wellman | City | — | 1,524 | 52356 |
| Riverside | City | — | 1,060 | 52327 |
| Brighton | City | Brighton | 600 | 52540 |
| Ainsworth | City | — | 511 | 52201 |
| Crawfordsville | Unincorp. | — | — | — |
| West Chester | Unincorp. | — | — | — |
| Coppock | Unincorp. | — | — | — |
| Richmond | Unincorp. | — | — | — |
| Noble | Unincorp. | — | — | — |
| Rubio | Unincorp. | — | — | — |
| Lexington | Unincorp. | — | — | — |
| Nira | Unincorp. | — | — | — |
| Havre | Unincorp. | — | — | — |
| Daytonville | Unincorp. | — | — | — |
| Grace Hill | Unincorp. | — | — | — |
| Haskins | Unincorp. | — | — | — |
| Mayflower MH Park | Unincorp. | — | — | — |
| Meadow Brook MH Park | Unincorp. | — | — | — |
Kalona sits astride the Washington–Johnson county line, but its post office, city hall, and the great majority of its population fall inside Washington County. Mayflower MH Park and Meadow Brook MH Park are licensed manufactured-home communities rather than platted towns, and both use Washington’s ZIP code.
Townships
| Township | Pop. (2020) | Main settlements |
|---|---|---|
| Washington | — | Washington (city) |
| Brighton | — | Brighton (city) |
| Cedar | — | — |
| Clay | — | — |
| Crawford | — | Crawfordsville |
| Dutch Creek | — | — |
| English River | — | — |
| Franklin | — | — |
| Highland | — | — |
| Iowa | — | — |
| Jackson | — | — |
| Lime Creek | — | — |
| Marion | — | — |
| Oregon | — | — |
| Seventy-Six | — | — |
The Census Bureau does not publish separate 2020 population counts for Iowa’s civil townships outside incorporated places, so figures are omitted rather than estimated.
ZIP Codes
- 52353 — Washington (also serves Mayflower MH Park and Meadow Brook MH Park)
- 52247 — Kalona
- 52356 — Wellman
- 52327 — Riverside
- 52540 — Brighton
- 52201 — Ainsworth
The unincorporated communities and rural crossroads across the county’s townships use the ZIP code of their nearest city post office rather than one of their own.
Geography
Washington County lies on the transition between the rolling Southern Iowa Drift Plain and the Iowa River valley, drained by the English River, Crooked Creek, and Long Creek. Almost all of the county’s 569 square miles of land is in row-crop agriculture, with timbered stream corridors along the English River and its tributaries.
The county is bordered by Iowa County to the northwest, Johnson County to the northeast, Louisa County to the east, Henry County to the southeast, Jefferson County to the southwest, and Keokuk County to the west.
Demographics
Washington County had 22,565 residents at the 2020 census, a density of about 40 people per square mile. Washington city and Kalona are the largest communities, together holding roughly 44% of the county’s population. Median household income runs close to the Iowa median of $71,433, with Kalona’s Amish and Mennonite farming economy and Washington’s manufacturing base both pulling incomes toward the state average rather than below it.
Economy & Local Life
Agriculture, food processing, and light manufacturing anchor the local economy. Washington is home to SEG Solar’s Iowa manufacturing plant and several long-running industrial employers along its rail corridor; Kalona sits at the center of one of Iowa’s largest Old Order Amish and Mennonite settlements, with dairy operations, produce auctions, and the Kalona Historical Village drawing regional visitors. The Washington County Fair, held each July in the county seat, is the county’s largest annual event.
History
Washington County was organized in 1839, renamed for George Washington after briefly being platted as Slaughter County in 1838; the county seat moved from the short-lived town of Astoria to Washington the same year. Early settlement followed the English River valley in the 1830s and 1840s, and Mennonite and Amish families began arriving near Kalona in the 1840s, founding what grew into one of the largest such settlements in the state.
Getting There
U.S. Route 218 runs north–south through the county past Riverside and Ainsworth, and Iowa Highways 1, 22, 27, 78, and 92 cross it in other directions.
- Iowa City — 20 miles northeast
- Fairfield — 25 miles southwest
- Mount Pleasant — 25 miles southeast
- Oskaloosa — 35 miles northwest
The nearest commercial airport is the Eastern Iowa Airport (CID) in Cedar Rapids, about 35 miles north of Washington.
Frequently Asked Questions
Where is Washington County, Iowa?
It is in southeast Iowa, part of the Iowa City metropolitan area, between the Iowa River and English River valleys.
What is the population of Washington County?
22,565 people at the 2020 census.
How big is Washington County?
571 square miles (1,480 km2), of which 569 square miles are land.
What is the county seat of Washington County?
Washington, Iowa, population 7,352.
How many towns are in Washington County?
Six incorporated cities — Washington, Kalona, Wellman, Riverside, Brighton, and Ainsworth — plus more than a dozen unincorporated communities.
What ZIP codes are in Washington County?
52353 (Washington), 52247 (Kalona), 52356 (Wellman), 52327 (Riverside), 52540 (Brighton), and 52201 (Ainsworth).
Is Kalona in Washington County?
Yes — most of Kalona lies in Washington County, though the city extends slightly into neighboring Johnson County.
More counties in this state: Towns and villages in Iowa.