I looked into our database, and unfortunately, this seems to be an instance of our weather service being flat-out wrong. Please accept my apologies--I've personally been researching alternatives to our current service, and this is a good argument in favor of us making a change.
As for schedule flexibility, our schedules are currently pretty rigid, to make sure that folks with mandatory watering restrictions don't get into trouble. But, I agree that this would be a neat feature. We'll look into it.