ZIP Code 52133 — Castalia, IA
52133 is a standard (street delivery) ZIP code serving Castalia, Iowa, in Winneshiek County. To mail something here you only need these five digits — but the four-digit extension narrows delivery to a single point, and it is what USPS bulk postage discounts are priced on.
ZIP code 52133 at a glance
| ZIP code | 52133 |
|---|---|
| Primary city | Castalia |
| State | Iowa (IA) |
| County | Winneshiek FIPS 19191 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 673 |
| Coordinates | 43.107020, -91.668540 |
How ZIP+4 works in 52133
The four digits after the hyphen encode a delivery segment inside 52133. In practice one segment usually means:
- One side of one block — odd numbers on a street between two cross streets
- A single large building, or one floor of it
- A group of PO boxes, sometimes a single box
- A single business that receives enough mail to warrant its own code
That is why 52133 has no single ZIP+4: two neighbors across the street from each other usually have different ones. Enter a street address above and we will return the exact nine-digit code along with the standardized USPS address format.
Nearby ZIP codes
Showing the closest twelve. See every ZIP code within 25 miles of 52133.
| ZIP | City | Distance |
|---|---|---|
| 52161 | Ossian, IA | 4.6 mi |
| 52162 | Postville, IA | 5.8 mi |
| 52135 | Clermont, IA | 6.1 mi |
| 52156 | Luana, IA | 10.9 mi |
| 52175 | West Union, IA | 11.1 mi |
| 52141 | Elgin, IA | 11.7 mi |
| 52166 | Saint Lucas, IA | 13.7 mi |
| 52132 | Calmar, IA | 14.4 mi |
| 52172 | Waukon, IA | 14.7 mi |
| 52144 | Fort Atkinson, IA | 14.9 mi |
| 52159 | Monona, IA | 15.6 mi |
| 52168 | Spillville, IA | 15.8 mi |
Questions about 52133
What is the ZIP+4 code for 52133?
52133 is the five-digit ZIP code. The ZIP+4 adds four more digits that identify a specific delivery point — usually one side of a city block, a single building, or a group of PO boxes. Because those four digits change from address to address within 52133, you need to look up a specific street address to get them.
What city is 52133?
52133 is assigned to Castalia, Iowa, in Winneshiek County.
Do I need to use the ZIP+4?
It is optional for ordinary mail, but it speeds up sorting and it is required for most USPS bulk-mail postage discounts. Many address-verification and e-commerce systems also use ZIP+4 to confirm a delivery point exists.
Need thousands of these?
Upload a CSV and get ZIP+4, county, carrier route, and delivery-point data appended to every row — or call the API directly.