Erica's Answer:
The average wind speed during the winter months of January through March is about 10.8 mph. Compare that to the summer months of July through September, wherein the average wind speed is only 8.2 mph. It's still not a big difference, but that increase in wind is due to the higher density of the arctic airmasses that we experience during the winter. Arctic air is a lot more dense than hot and humid air, so when a shot of arctic air rolls into the Delaware Valley, it's much more forceful, and therefore windy, than hot and humid air!- Erica
