Hi Jonathan!

The effects of the Sun's variability on Earth's climate are not well-understood and this is a topic of much research. From what I have read, the warm winter weather was due to an extremely unusual jet stream over North America. The jet stream over North America is controlled by climate patterns called the North Atlantic Oscillation and the Arctic Oscillation, which are caused by differences in sea-level pressure across certain stretches of the globe. This year, these variations in pressure pulled warm air from the southwest over the Eastern US, instead of the cold Arctic air we usually get in the winter. There have been some studies linking variations in the North Atlantic and Arctic Oscillations to the 11-year solar cycle, but these studies show a connection between low solar activity and cold winters in North America and northern Europe. We have had low solar activity over the last few years, and it doesn't look like we will reach solar maximum until 2013, so there really isn't a clear connection between the unusually warm weather we have had and solar activity.

Kris