Well, it is a little difficult to say. In early Fall, Late September/Early October, it is still pretty hot, but sometimes in the 70s at night. So I would still pack summery type attire. I do start checking the weather about a week out so I can get a better idea if I need to pack multiple options. If you go in January though, I have been there with it snowing before! When I was running in the Half Marathon in 2010, it totally snowed on us while we were running, and the rest of the time there, it was very cold and rainy. So definitely need warmer clothes. It is a little tough to decide, it is a little easier on us since we don't have to fly because really I could just pack as much as I wanted and it wouldn't matter. What month are you guys going? I may could give you a better idea based on that?