The one that I installed is not weather proof but I don't intend to run the generator in the rain or snow, it will always be protected. Doing great so far.
The backlight on my cheapie has died already but the meter still works fine and I can read it with my flashlight or in daylight. Since I always have one or the other when I start it it's a non issue. I keep my machine under a shed and the instruments have a door over them so they are never directly subjected to the weather but will see some condensation.