Below is a list of South Plainfield NJ zip codes. For your research we have also included South Plainfield Area Code, Time Zone, UTC and the local Middlesex County FIPS Code. Each South Plainfield New Jersey zip code has a center Longitude / Latitude point (the South Plainfield center is -74.414199829102 / 40.576499938965). For your convenience we have also indicated if that zip code in South Plainfield observes Daylight Savings time.