Do you cancel a planned trip for bad weather?

This is a question I find myself in limbo every time I plan a trip. No one can accurately predict weather or weather changes. I usually plan my trips months in advance completely unaware of any inclement weather to come. Two weeks before I travel, I always check the weather forecast for my area and area that I'm traveling to. The only way I will cancel a trip due to bad weather is if I have a trip to the beach planned that is within driving distance and still within the cancellation period. I believe a trip to the beach should have the perfect weather because 9 times out of 10 you are going to enjoy beach activities. I will also cancel if I know the weather in my destination will be bad enough to put me or my family in danger during traveling. What are your thoughts?....What factors would make you cancel a planned trip....