Below is a list of Garrison IA zip codes. For your research we have also included Garrison Area Code, Time Zone, UTC and the local Benton County FIPS Code. Each Garrison Iowa zip code has a center Longitude / Latitude point (the Garrison center is -92.143798828125 / 42.144199371338). For your convenience we have also indicated if that zip code in Garrison observes Daylight Savings time.