Passaic is a city in Passaic County, New Jersey, United States. As of the 2010 United States Census, the city had a total population of 69,781. Located north of Newark on the Passaic River, it was first settled in 1678 by Dutch traders, as Acquackanonk Township. The climate in this area is characterized by hot, humid summers and generally mild to cool winters. Passaic has a humid subtropical climate.