Below is a list of Williamson IA zip codes. For your research we have also included Williamson Area Code, Time Zone, UTC and the local Lucas County FIPS Code. Each Williamson Iowa zip code has a center Longitude / Latitude point (the Williamson center is -93.255798339844 / 41.087799072266). For your convenience we have also indicated if that zip code in Williamson observes Daylight Savings time.