Below is a list of Colchester IL zip codes. For your research we have also included Colchester Area Code, Time Zone, UTC and the local Mcdonough County FIPS Code. Each Colchester Illinois zip code has a center Longitude / Latitude point (the Colchester center is -90.793296813965 / 40.426300048828). For your convenience we have also indicated if that zip code in Colchester observes Daylight Savings time.