There's a saying in Germany that translates to something like, "there is no bad weather, only wrong clothing". If you are a gigging musician willing to perform outdoors, you better remember this bit of wisdom!
A few months ago, I was booked to play at a women's conference. I was directed to the garden of the building, so attendants could listen to my music while enjoying some fresh air. Now, you must know that I keep my receiver, microphone and other equipment in a hard case that protects it from collisions and the weather. Once I set up, though, my PA system is as exposed to the elements as I am. That day, once we were done and had all the equipment out, it started to drizzle. Of course, panic ensued! You just can't allow electric devices to get rained over, unless they are made waterproof (and even so, it's better not to risk it).
It was stressful, but fortunately, the light rain passed, and at the end, I could perform. Soon after, I started looking into acquiring some specialised protection from the rain. There are many options, and it's always good to be prepared!