County ZIP codes · Iowa · FIPS 19191

Winneshiek County, IA ZIP Codes

Winneshiek County, Iowa has 13 ZIP codes (Census 2020 ZCTA-county file; GeoNames postal codes, October 2026): 12 residential and 1 for PO boxes or a single organization. 7 of the residential ones lie mainly in Winneshiek County and 5 mainly in a neighboring county; 10 cross the county line. Median household income ranges from $64,125 in 52162 (Postville) to $100,559 in 52132 (Calmar) (Census Bureau, ACS 2020-2024).

ACS2020-24
Census2020

Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).

How different are its ZIP codes?

52162 · $64k 52132 · $101k

The middle half of its ranked ZIP codes (1,000+ people living in households) report median household incomes between $68,875 and $87,870.

They carry 12 postal town names.

Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B19013).

All 12 residential ZIP codes in Winneshiek County

7 ZIP codes lie mainly in Winneshiek County; 5 more reach into it from a neighboring county and follow the first table.

Residential ZIP codes mainly in Winneshiek County, largest first; "In this county" is the share of the ZIP's land in the county
						In this county
52101	Decorah	12,706	40	$74k	$273k	97%
52132	Calmar	1,759	28	$101k	$232k	98%
52161	Ossian	1,532	29	$88k	$171k	86%
52165	Ridgeway	1,098	16	$85k	$292k	100%
52144	Fort Atkinson	1,075	14	$85k	$218k	94%
52133	Castalia	673	15	$76k	$246k	70%
52168	Spillville	356	939	$54k	$158k	100%

Partly in Winneshiek County

Residential ZIP codes mainly in another county that reach at least 1% into Winneshiek County, by their share here
						In this county
52136	Cresco	5,840	28	$71k	$161k	33%
52171	Waucoma	1,314	16	$95k	$192k	18%
52162	Postville	3,744	39	$64k	$133k	10%
52140	Dorchester	671	9	$72k	$208k	9%
52172	Waukon	5,877	37	$69k	$166k	5%

Download the 13 ZIP codes as CSV

Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; county shares by land area (Census 2020 ZCTA-county relationship file).

Which ZIP codes cross the county line?

10 ZIP codes of Winneshiek County extend into another county. A ZIP code follows mail routes, not county borders.

Share of each ZIP code's land in Winneshiek County and in the neighboring counties
ZIP	In Winneshiek	Elsewhere
52101	97%	Allamakee County 3%
52172	5%	Allamakee County 95%
52136	33%	Howard County 67%
52162	10%	Allamakee County 60%; Clayton County 27%; Fayette County 3%
52132	98%	Howard County 2%
52161	86%	Fayette County 14%
52171	18%	Fayette County 50%; Chickasaw County 31%
52144	94%	Fayette County 6%
52133	70%	Fayette County 30%
52140	9%	Allamakee County 91%

Source: U.S. Census Bureau, 2020 ZCTA-county relationship file (shares of land area).

PO Box and single-organization ZIP codes

ZIP codes in Winneshiek County without a residential area (GeoNames postal codes)
ZIP	Postal name
52149	Highlandville

Source: GeoNames postal codes (CC BY 4.0).

Which first three digits do Winneshiek County's ZIP codes use?

The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. Every ZIP code of Winneshiek County starts with 521.

Three-digit prefixes of Winneshiek County's ZIP codes, the sectional center for each (USPS labeling list L005, effective October 1, 2026) and how many of the prefix's codes are Winneshiek County's
Prefix	Sectional center	Here	All codes
521	Waterloo, IA (SCF 506)	13	33

Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.

Where are the ZIP codes of Winneshiek County?