Snow and freezing weather in San Francisco Bay Area?

Yes my friends it actually snowed on the hills this past weekend. When I went out for my mountain bike rides this past week the temperature has been in the high 30s to low 40s in the morning never getting above 56 in the afternoons.  I was surprised to actually see people jogging and cycling in shorts. I was almost warm wearing two pairs of cycling tights and a heavy shirt and cycling jacket.  I guess some people just do not feel the cold or can ignore it.