Snowy! Fresh light falling snow. I was lucky, (or smart, I did follow the weather forecast very closely) and managed to leave work just as the snow started falling, and got all the way home before it really started thickening on the road. A friend of mine left 2 hours later to ride the same route and wiped out spectacularly, ending up sliding downhill behind a car that was braking... but got out of it with just a dented helmet.