Below is a list of Walnut IA zip codes. For your research we have also included Walnut Area Code, Time Zone, UTC and the local Pottawattamie County FIPS Code. Each Walnut Iowa zip code has a center Longitude / Latitude point (the Walnut center is -95.222099304199 / 41.476001739502). For your convenience we have also indicated if that zip code in Walnut observes Daylight Savings time.