There are many ways to analyze climate data. The most familiar is based on the calendar year, January through December. Hydrologists make use of what they refer to as the water year, which runs in most areas from October through September. If we want to admit it or not, we live in a cold dominated climate and therefore, using the cold season to represent variations in climate often highlights differences between years better as frequently, it is the five coldest months of November through March that set different years apart.
The cold season stats run from July 1 through June 30, these dates already mark the time frame for official snow tallies. This means Saturday will mark the end of the 2011-2012 cold season and these past 12 months will go down as the warmest such period on record besting 1986-1987 by a remarkable 1.6 degrees. Before this year, the difference between the two warmest cold seasons was only 0.2 degrees and the two coldest years were separated by 0.9 degrees, making these past 12 months unique in the record book.