N.J. weather: Temps hit -17 overnight. Cold weather advisory issued for 16 counties.
Two towns in Sussex County — Walpack and Sandyston — reported overnight low temperatures of -16 degrees between 7 and 8 a.m. Wednesday morning before Walpack dropped a bit more, down to -17 degrees one hour later, according to data from the Rutgers NJ Weather Network, overseen by the state climatologist’s office.