We have continued to enjoy temperatures well above normal through most of February 2012, making this year’s Dec. 1–Feb. 20 the fifth-warmest on record with an average temperature of 28.3F in Madison. Barring an exceptionally warm last week of the month (which does not appear likely), that is where we will end up — the fifth-warmest winter (defined as December, January, February) of all time in Madison.
A natural next question is what does the winter warmth portend for the coming spring and summer. Colleagues at the National Weather Service Forecast Office in Sullivan, Wis., have thought about this question. Though speculation about such a connection is derived purely from statistics, the statistics do tell an interesting story.
First, let’s define spring as March, April and May and summer as June, July and August. Then, ranking the past 141 years of springs and summers from warmest (rank 1) to coldest (rank 141), they have calculated the average rank for the springs and summers following the 20 warmest winters in Milwaukee (results likely very similar for Madison).
It turns out that the spring following an exceptionally warm winter, on average, has been warmer than 60 percent of all springs. Even more intriguing, the summers following exceptionally warm winters have been warmer, on average, than 69 percent of all summers. Those are pretty good odds for a warmer-than-normal spring and summer.