I enjoy running in the snow as long as it's not too windy. 20-30 degrees is my sweet spot for cold weather running. 30-40 degrees is tough for me because I tend to overheat in my layers around that temperature.
That being said, I learned to love running while I was living in the deep south, so I hold a very unpopular love for warm weather running, especially in 60-80 degree weather. As long as I don't go too fast and stay hydrated, I'm happy!