There's an economics professor at RPI who likes to describe the weather by saying: "The only time it's nice here is the first week in fall and the last week in spring." That's a bit of an exaggeration, but not much. During the school year, it is cold most of the time-from mid-October until at least mid-April, though it tends to vary by the year. An Indian summer in November or a snow squall in mid-May are fairly common.
In the winter, Troy usually averages between four and five and a half feet of snow. It can be spread out over the course of the winter, or it can hit you all at once in a weekend. Bring a varied wardrobe, and be ready for anything. You never know what will happen from day to day, or even from dawn to dusk. For the most part, though, count on cold and rainy.