Weather whether or not
When you count on it being sunny, it will rain. When you count on it being cold it will be hot. When everything you do depends on weather conditions, always have a back up plan. The best back up plans are rarely used. Why? Well, the best back up plans are made by the people who make excellent initial plans to begin with.
If you find yourself always falling back to the back-up plan then you need to put someone else in charge of making the initial plans.