I shoot primarily architectural photography. At the moment, I generally do the cancellation scaling as mentioned above with 72 hours, 48, 24, day of, as well. My fees are paid if this was due to client issues or problems not related to me. And expenses get paid no matter what...so assistants, stylists, rentals, etc... On the architectural stuff however, I rarely charge because of weather. Neither I nor the client can control that, and I certainly don’t want to deliver shots that don’t live up to my quality nor meet the needs of my client. If it rains or snows, we delay if possible. The client understands though that we are then on standby based on my schedule as well. They are still locked in and need to allow me the chance to still shoot. I don’t let them off the hook either. Sometimes we just concede and shoot anyways if we can get away with it and then drop in a new sky for instance assuming the rest of the shot still has some decent contrast and tones.