I have to give a quick defense to some promoters, though.
It is very hard to make the tough call of a cancellation or reschedule due to weather. You can sit on that radar screen all frigging morning and GUESS what's going to happen at 2, 3, 4 in the afternoon. Meanwhile, your phone is blowing up from guys travelling to the show (you know, the guys who PUT ON the show), and you're stuck between a rock and a hard place.
Perfect example is last week at Dundee. The weather Tuesday was warm and muggy - the perfect set up for rain and thunderstorms right at the time the gates are set to open. And another round of showers predicted at hot lap time, then at heat time. You have teams travelling from at least 4 hours away, and you wat to do right by them and call it early so they don't start out and get half way there for a rain out. (Come to find out, Mother Nature had a little fun with Brett and Tyler and they really didn't get anything all afternoon at the track.) So you use the built in rain date, which turns out to be cold, and windy, and miserable. :shrug: There is no easy decision to calling a show due to weather.