Below is a list of Denison IA zip codes. For your research we have also included Denison Area Code, Time Zone, UTC and the local Crawford County FIPS Code. Each Denison Iowa zip code has a center Longitude / Latitude point (the Denison center is -95.351898193359 / 42.012401580811). For your convenience we have also indicated if that zip code in Denison observes Daylight Savings time.