No idea about your camera or it's physical configiration. Mine is situated behind the end cap, which has a hood and a protective piece of glass over the camera lens, the whole setup keeps the entire camera out of the weather. However, in hard rain, water will accumulate on the glass obscuring my vision. I of couse clean the glass when it gets dirty.
If your camera is out in the open, not much you can do until the rain stops.
If you mean your display acts up during rain, then it sounds like water may be getting into the video cable connection on the camera.
John & Clare - Buck & Zeus - Jack & Husky
2008 Fleetwood Bounder 38P
Towd: 2 HD Streetglides