Below is a list of Dorchester IA zip codes. For your research we have also included Dorchester Area Code, Time Zone, UTC and the local Allamakee County FIPS Code. Each Dorchester Iowa zip code has a center Longitude / Latitude point (the Dorchester center is -91.511199951172 / 43.469200134277). For your convenience we have also indicated if that zip code in Dorchester observes Daylight Savings time.