Below is an analysis of the average temperature history by decade of our winter months of December, January and February here in the philly burbs of Western Chester County. As always our climate is very cyclical in it's warming and cooling cycles. By decade we have had 6 decades with increased average temps vs the prior decade and 5 decades with colder temps than the prior decade. Of note the 3 coldest DJF decades occurred during our last cold cycle in the 1960's through the 1980's.