Castalia Iowa ZIP Codes
Castalia holds a single ZIP code.
Every ZIP code in Castalia
| ZIP code | County |
|---|---|
| 52133 | Winneshiek County |
We do not publish a delivery type (standard, PO box, unique) or a neighbourhood for each ZIP. USPS delivery-type products are licensed, and no clean-rights source maps ZIP codes to neighbourhoods — so the Castalia codes above are listed without a column we would have to invent.
Scope every ZIP code recorded for Castalia. Source GeoNames US postal codes (2026-07 postal dump) and Census 2024 county Gazetteer (2024 Gazetteer). Updated . ZIP codes are delivery-route groupings, not areas; the boundaries implied by any ZIP map are approximations.
How these codes cluster
Every Castalia ZIP code begins 521. Those first three digits identify the sectional center facility that processes mail for this part of Iowa. Statewide that range covers 33 ZIP codes, so Castalia accounts for 3% of it.
Every Iowa ZIP prefix and the region it covers →
Area codes covering Castalia
ZIP codes and area codes are separate systems — one routes mail, the other routes calls — and they do not share boundaries. The code below serves the same ground Castalia occupies.
Castalia Iowa area codes in full →
Where Castalia's ZIP codes sit
- Reference points and footprint
- Not an official NANPA boundary
- Not a USPS delivery area
Cities near Castalia
| City | Distance | ZIP codes |
|---|---|---|
| Ossian Iowa ZIP codes | 5.0 mi | 1 ZIP code |
| Postville Iowa ZIP codes | 5.8 mi | 1 ZIP code |
| Clermont Iowa ZIP codes | 7.9 mi | 1 ZIP code |
| Calmar Iowa ZIP codes | 11 mi | 1 ZIP code |
| Elgin Iowa ZIP codes | 11 mi | 1 ZIP code |
| Luana Iowa ZIP codes | 12 mi | 1 ZIP code |
| West Union Iowa ZIP codes | 13 mi | 1 ZIP code |
| Fort Atkinson Iowa ZIP codes | 13 mi | 1 ZIP code |
Straight-line distance between place reference points, not driving distance.