Below is a list of Dewey County SD zip codes. For your research we have also included Dewey County Area Code, Time Zone, UTC and the local County FIPS Code. Each Dewey County South Dakota zip code has a center Longitude / Latitude point (the Dewey County center is -101.08699798584 / 45.236099243164). For your convenience we have also indicated if that zip code in Dewey County observes Daylight Savings time.