Staying dry can come at a cost, though: Waterproof jackets are often less breathable. To solve this problem, some brands now use a breathable membrane like Gore-Tex, a popular waterproofing technology (because, even in the middle of a downpour, no one wants to feel swampy). Kirkland Shave, program creator and acting program director at Mountain Trek, a hiking-centric wellness retreat in British Columbia, Canada, recommends Gore-Tex jackets because they allow air to flow and wick sweat away when you’re active, while keeping the rain out.
When shopping, look for a rain jacket’s waterproof and breathability rating—not all brands provide it, but if they do, it’ll be listed as two numbers separated by a backslash. The first number (given in millimeters) represents waterproofing, and the second (given in grams) indicates breathability. Both work on scales of 0 to 20,000+: The higher the numbers, the more waterproof and breathable the jacket will be. When it comes to waterproofing, “I’m not taking any jacket below 15,000 millimeters,” says Rubén Perez, co-founder of 5-Element Travel and hiking guide at Kerlingarfjöll Highland Base in Iceland.
