It takes significant wind or rain, and only sometimes snow, for me to wear a jacket. I'd rather layer with breathable clothing. Sporthill pullovers are a good choice down to about 25F and no wind. That harder finish lycra with the software brushed interior can handle a lot. If I wear a jacket, I wear the thinnest top possible. I adore Ibex or Icebreaker liner gloves for running down to about the same temp. No standing around after of course!

My jacket options include a wind vest, a whisper thin PI jacket (almost like tissue), a NorthFace water resistant windbreaker that is slight heavier but less breathable, and I just picked up Salomon Minim jacket (non-Goretex version) because I think I'll be going out with our local snowshoe running group so I'll be locked into a rain-or-shine schedule.