I was born in Watertown (awesome, eh?) and have spent a lot of time up there in my days. When those Canadian high pressure systems float in, it can easily drop well, well below 0 as many have mentioned. If you like snow, you are in business since the snowiest place on the east cost (Pulaski, NY) is just a wee bit south of Ft. Drum. Unfortunately there aren't any good hills to go along with that snow. Also, if you can get off the base and into the country a bit it is without a doubt the best star visibility that I have ever encountered.
Enjoy the real, REAL upstate NY.