T's only request was that I called BEFORE session to notify. Even 2 minutes before was better than not calling and not showing up. No call/no show was a pet peeve of hers.
Never a charge for a missed session. So, if weather was an issue, I just called ahead of time to cancel and reschedule.
Same with new T. T even said that if it's snowing and there is more than 2 inches of snow, she does not want her clients trying to get to an appointment.