Twenty-three years ago today we were in the midst of what was to become the coldest winter on record in Philadelphia and the coldest month of the 20th Century in many parts of Delaware and Pennsylvania.

On this day in 1977, morning temperatures dropped below zero, and the afternoon high in Philadelphia only recovered to 8 degrees.

While it's not unusual in places such as Minneapolis, Minnesota, or Caribou, Maine, for the temperature to stay below 10 degrees during the day in the winter, in this area it's very very rare - in fact, it's happened in Philadelphia only 9 times in 125 years of official records, or on average, once every 15 years. That was truly an extraordinarily cold month, January 1977.