Below is a list of Stewartsville NJ zip codes. For your research we have also included Stewartsville Area Code, Time Zone, UTC and the local Warren County FIPS Code. Each Stewartsville New Jersey zip code has a center Longitude / Latitude point (the Stewartsville center is -75.111099243164 / 40.694000244141). For your convenience we have also indicated if that zip code in Stewartsville observes Daylight Savings time.