Below is a list of Mascoutah IL zip codes. For your research we have also included Mascoutah Area Code, Time Zone, UTC and the local Saint Clair County FIPS Code. Each Mascoutah Illinois zip code has a center Longitude / Latitude point (the Mascoutah center is -89.803199768066 / 38.525501251221). For your convenience we have also indicated if that zip code in Mascoutah observes Daylight Savings time.