Ripstop nylon (which is also very durable!) and polyester are great materials for heavy downpours because they are tightly woven together. Water-repellent surfaces on the cover made of polyester keep you dry.
People Also Ask
Rain covers can also protect gear stored on the outside of your backpack from getting wet. If you store a tent, food, a stove, or clothing in the outside pockets of your pack because you prefer to, or because you don't have enough volume inside your backpack, a rain cover can keep them dry and protect them from damage.
Pick up a pack coverCovering your backpack with a pack cover is a great, inexpensive way to keep your bag from getting soaked — and to keep it light. (A wet bag plus wet gear equals a heavy pack!)