Below is a list of Potosi MO zip codes. For your research we have also included Potosi Area Code, Time Zone, UTC and the local Washington County FIPS Code. Each Potosi Missouri zip code has a center Longitude / Latitude point (the Potosi center is -90.784599304199 / 37.934299468994). For your convenience we have also indicated if that zip code in Potosi observes Daylight Savings time.