Below is a list of Summerfield IL zip codes. For your research we have also included Summerfield Area Code, Time Zone, UTC and the local Saint Clair County FIPS Code. Each Summerfield Illinois zip code has a center Longitude / Latitude point (the Summerfield center is -89.751998901367 / 38.596599578857). For your convenience we have also indicated if that zip code in Summerfield observes Daylight Savings time.