Below is a list of Belvidere IL zip codes. For your research we have also included Belvidere Area Code, Time Zone, UTC and the local Boone County FIPS Code. Each Belvidere Illinois zip code has a center Longitude / Latitude point (the Belvidere center is -88.854499816895 / 42.257400512695). For your convenience we have also indicated if that zip code in Belvidere observes Daylight Savings time.