While it’d be nice to know for sure when (and if) you’ll need a jacket on your next trip, even we can’t predict that. What we can do is handpick outerwear essentials from the best lightweight raincoats for a spring day in the Pacific Northwest to something uber-toasty for winter in Iceland to aid your planning process. All temperatures are covered here, with an emphasis on multipurpose, packable pieces because, when traveling, layers are quite often your best friend.