You don't need to bring a full-on fisherman-style rain slicker to keep you dry in the mountains. Not only is the Rab Atmos Women's Jacket lighter and easier to pack, but its Pertex Shield+ 3L membrane is breathable as well as waterproof, so you won't sweat to death if you're climbing, hiking, or pushing for the summit. It weighs well under a pound, too, so it won't slow you down, and it has climbing and hiking-ready features like a helmet-compatible hood, high hand pockets, and a low-profile half hem drawcord that won't ride up or bunch. The cuffs close with a combination of elastic and hook-and-loop tabs to keep water out of your sleeves, and the slim fit eliminates extra fabric that will just get in way when you're climbing tough pitches or scrambling up ridges.