Here is the comments from the weather intern who lives up there:
Sunday saw some of the most extreme weather on Mount Washington in years. That's right, good weather on the summit can be considered extreme. At 42F we smashed the old record high of 33F set in 1938. Just one degree shy of the all-time monthly record. Monday's record high has also been exceeded. Daily records are broken quite regularly though, often several times a year. The extreme event happened around 9am when the winds became completely calm. Even the slightest breath of air could not be found on the summit. If you visit the top of Mount Washington in the winter you are more likely to experience 130mph gusts than calm winds.
With all the nice weather in the mountains there was a flood of activity on the Rockpile this weekend. Scores of people reached the summit on both Saturday and Sunday. At times the Observation Deck was as crowded as a summer afternoon, and the summit crew could be seen playing baseball. In the late afternoon I found corn snow skiing the east snowfields. What a weekend!
For perspective, here are the archived pages of Mt. Washington weather from the same day in recent years:
Feb. 6, 2002