Below is a list of Castlewood SD zip codes. For your research we have also included Castlewood Area Code, Time Zone, UTC and the local Hamlin County FIPS Code. Each Castlewood South Dakota zip code has a center Longitude / Latitude point (the Castlewood center is -97.031997680664 / 44.731800079346). For your convenience we have also indicated if that zip code in Castlewood observes Daylight Savings time.