Below is a list of South Wilmington IL zip codes. For your research we have also included South Wilmington Area Code, Time Zone, UTC and the local Grundy County FIPS Code. Each South Wilmington Illinois zip code has a center Longitude / Latitude point (the South Wilmington center is -88.2639 / 41.1733). For your convenience we have also indicated if that zip code in South Wilmington observes Daylight Savings time. For more information on South Wilmington Illinois you will find helpful business links and searches.