Below is a list of Monmouth Junction NJ zip codes. For your research we have also included Monmouth Junction Area Code, Time Zone, UTC and the local Middlesex County FIPS Code. Each Monmouth Junction New Jersey zip code has a center Longitude / Latitude point (the Monmouth Junction center is -74.546401977539 / 40.379199981689). For your convenience we have also indicated if that zip code in Monmouth Junction observes Daylight Savings time.