The autumn of 2009 was one of the most unique on record. September that year was the 2nd warmest on record. After a very cold summer, September 2009 was a very welcomed extension of the warm season.
But that all changed on October 1 when two inches of cold rain fell behind a powerful cold front that quickly turned the area from warm to cold. During the first two weeks of that month the temperature never exceeded 54 degrees; in fact, there were more days with highs in the 30s than the 50s during that stretch. October 2009 finished as the 9th coldest on record.
Then on November 1, the temperature climbed well above average and stayed there for the entire month. It was so mild that November 2009 finished as the 2nd warmest on record. So the area experienced two almost record breaking warm months with a very cold month sandwiched in between.
It makes going from 80 degrees to snow last week seem not so strange after all.