Below is a list of Ionia County MI zip codes. For your research we have also included Ionia County Area Code, Time Zone, UTC and the local County FIPS Code. Each Ionia County Michigan zip code has a center Longitude / Latitude point (the Ionia County center is -85.059600830078 / 42.986400604248). For your convenience we have also indicated if that zip code in Ionia County observes Daylight Savings time.