Below is a list of Williamsfield IL zip codes. For your research we have also included Williamsfield Area Code, Time Zone, UTC and the local Knox County FIPS Code. Each Williamsfield Illinois zip code has a center Longitude / Latitude point (the Williamsfield center is -90.014198303223 / 40.926399230957). For your convenience we have also indicated if that zip code in Williamsfield observes Daylight Savings time.