My 1 and 2W Blazes have been fine in the occasional rain I've ridden in. I put a very very thin film of silicone grease on the seals of my lights and other electronic equipment exposed to water as is done for scuba lights, underwater camera housing, etc.. This improves the seal but also creates a hydrophobic surface which helps repel water. As mentioned by others, if you suspect any water or condensation has gotten in, open the light and let it dry out. Gentle warming, like sitting on top of your water heater, etc. will help, especially if it's very humid.