Rain on your wedding day. To many, this is the absolute worst thing that can happen at a wedding, particularly if it is being held outdoors. This is why if you are holding either your ceremony or reception en plein aire as the French would say, it is imperative that you have a rain plan. That may be a tent, or an indoor space, but with 150 people arriving, you don’t want to be making arrangements at the last minute. So find an alternate location, and decide how it will be communicated to guests ( a phone tree, signs or people directing at the original site). Don’t leave anyone standing in the rain.