Whiteside County ZIP Codes

Whiteside County is a county of Illinois.

ZIP codes
12
Cities & towns
12
Area codes
4
Land area
684 sq mi

Every ZIP code in Whiteside County

610xx–612xx
The complete list of Whiteside County, IL ZIP codes with the city each one delivers to.
ZIP codeCity
61037Galt
61071Rock Falls
61081Sterling
61230Albany
61243Deer Grove
61250Erie
61251Fenton
61252Fulton
61261Lyndon
61270Morrison
61277Prophetstown
61283Tampico

We do not publish a delivery type (standard, PO box, unique) or a neighbourhood for each ZIP.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 Whiteside County codes above are listed without a column we would have to invent.

Cities and towns in Whiteside County

A further 2 places in Whiteside County appear in the postal source without a page of its own; their codes are in the table above and each one links to its own page.

Area codes covering Whiteside County

Telephone and postal boundaries are drawn by different bodies, so these codes overlap the county without matching its edges.

Where Whiteside County's ZIP codes sit

Each point is the reference point of one Whiteside County ZIP code, plotted from its record coordinates. The outline is the convex envelope of those points — a footprint, not a boundary.
  • Reference points and footprint
  • Not an official NANPA boundary
  • Not a USPS delivery area

Scope every ZIP code recorded in Whiteside County. Source GeoNames US postal codes (2026-07 postal dump), Census 2024 county Gazetteer (2024 Gazetteer) and geoinfo-dataset (full_dataset) ZIP→NPA (2018 snapshot). Updated . The outline is a convex envelope of ZIP reference points, not a jurisdiction boundary.