The National Climatic Data Center (NCDC)
reports that 2006 was the warmes year on record in the US.
"No cause for alarm. Enjoy it while you have it," said Mike Halpert, head of forecast operations at the National Oceanic & Atmospheric Administration's Climate Prediction Center. Jeff Masters disagrees and "had a lot of trouble enjoying the phenomenally warm weather of the past month here in Michigan."
Dr. Jeff Masters' WunderBlog at wunderground.com as usual has lots of interesting graphs and charts.