Below is a list of Dupo IL zip codes. For your research we have also included Dupo Area Code, Time Zone, UTC and the local Saint Clair County FIPS Code. Each Dupo Illinois zip code has a center Longitude / Latitude point (the Dupo center is -90.205200195312 / 38.508800506592). For your convenience we have also indicated if that zip code in Dupo observes Daylight Savings time.