One of my favorite hikes last summer was rainy, which just added to the experience! I took the train from Lauterbrunnen to Wengen and then the lift up to Mannlichen. When the lift arrived, we were in a cloud - could see hardly anything. I had a small umbrella in my pack, and a windbreaker, so headed out down the mountain, and had it practically to myself; only one other couple on the entire path. I started out with on the road cleared and snow all around and loved seeing the mists - as I got lower the snow disappeared and when I got down to the bottom of the ski lift, the snow was gone. The rest of the day was fine, with intermittent sun and rain. I ended up catching the train back to Wengen - wonderful day in the Alps, rain and all! Take your rain gear and go for it!