| Code | Name | Region |
|---|---|---|
| USNGX | Winnebago | NE |
| USWGB | Winnebago, Faribault | MN |
| USYEC | Winneconne | WI |
| USWMC | Winnemucca | NV |
| USXWZ | Winner | SD |
| USDZS | Windsor | IL |
| US5WO | Windsor | MA |
| USQZJ | Windsor | ME |
| US6MO | Windsor | MO |
| USWNJ | Windsor | NJ |
| USXNS | Windsor | NY |
| USOW6 | Windsor | SC |
| USXWN | Windsor | VA |
| USWIV | Windsor | VT |
| USXOC | Windsor | WI |
| USW5H | Windsor Heights | IA |
| USZRI | Windsor Heights | WV |
| USWLC | Windsor Locks | CT |
| USBDL | Windsor Locks-hartford Apt | CT |
| USWM9 | Windsor Mill | MD |
| USINB | Windsor, Bertie | NC |
| USIW3 | Windthorst | TX |
| US2HO | Winesburg | OH |
| USIAU | Winfall | NC |
| USWIF | Winfield | AL |
| USWCV | Winchester | TN |
| USWGO | Winchester | VA |
| USYST | Winchester | WA |
| USWCC | Winchester Center | CT |
| USWNG | Wind Gap | PA |
| USW56 | Wind Ridge | PA |
| USWID | Windber | PA |
| USWDR | Winder | GA |
| USWMY | Windermere | FL |
| USWF4 | Windfall | IN |
| USWMJ | Windham | CT |
| US6DW | Windham | ME |
| USWKH | Windham | NH |
| USWHM | Windham | OH |
| USDHM | Windham Hill | ME |
| USW7M | Windom | KS |
| USMWM | Windom | MN |
| USWOX | Windsor | CA |
| USWSR | Windsor | CO |
| USWND | Windsor | CT |
| USQCW | Wilton | CT |
| USIOV | Wilton | IA |
| USWYT | Wilton | ME |
| USWIO | Wilton | NH |
| USWIM | Wilton | NY |