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How to waterproof a backpack: 3 simple solutions to stay dry

A hiker by a lake in the rain
Knowing how to waterproof a backpack keeps soggy sandwiches at bay and makes sure your best gear is protected from downpours on the trail (Image credit: bingokid)

As an adventure lover, you’re probably not one to let a little rain keep you from the trail, but that’s not to say you’re ok with soggy sandwiches and malfunctioning phones. Knowing how to waterproof a backpack is useful to protect your electronics and lunch on a day hike, and can be life-saving when need to keep your spare clothes and sleeping bag dry in a deluge to avoid hypothermia on a multi-day thru-hike

Though the best backpacks meant for hiking and camping are made using water resistant materials and come with double taped seams that are sufficient against light rain, even the best won’t hold up against a proper, sustained downpour. Fortunately, there are a few really easy fixes to waterproof your backpack and protect the gear inside it so you can keep getting miles underfoot in your hiking boots. Read on for our three simple solutions for hiking in the rain with a backpack. 

A woman hiking in Ireland in the rain

A rain cover slips over your pack to keep everything dry (Image credit: Jean-Philippe Tournut)

1. Waterproofing spray and seam sealer 

In the same way that you can waterproof a tent and other outdoor gear, you can use waterproofing spray (opens in new tab) on your backpack. You always want to start with a clean item so to begin, follow the steps in our article on how clean a backpack, allow your pack to dry completely, then apply one or two coats of waterproofing spray.

Often, a lot of the moisture gets in through the seams, zips and any holes from wear and tear, so after the backpack has dried you can reinforce your efforts by using a seam sealer (opens in new tab) on those areas. You’ll want to let the treatment dry completely before using your bag, so this is all work you’ll want to do at least the day before you head out.

This option is definitely the most labor intensive, and requires you to prepare your backpack in advance of getting on the trail. However, if you’re going on a long backpacking trip, or you just live and hike somewhere that gets a lot of rain, it’s a good preventative measure.

A hiker in the rain

If you’re going on a long backpacking trip, or you just live and hike somewhere that gets a lot of rain, you may want to use waterproofing spray on your backpack before you go (Image credit: Preserved Light Photography)

2. Rain cover 

This option requires no advance preparation other than buying a rain cover that fits your backpack, and remembering to carry it with you. Then, if the skies start to darken while you’re out on a hike, just whip it out, pull it over your backpack and everything inside will stay nice and dry. Rain covers are inexpensive, lightweight and pack down small so this is a great option. 

3. Pack liner 

This option is perfect for those who don’t want to stop on the trail and start fussing around with gear, but also don’t want to spend time with waterproofing spray. Instead of packing your gear directly into your backpack, you can place it all in a sealable, waterproof liner that fits inside your backpack, so even when your pack gets soaked, your spare hiking socks and camping stove stay bone dry. A pack liner is another affordable option and doesn’t add weight, and if you’re on a budget, you can even use a trash bag. When you get home, just remember to let your backpack dry out before you pack it away. 

Julia Clarke is a staff writer for Advnture.com and the author of the book Restorative Yoga for Beginners. She loves to explore mountains on foot, bike, skis and belay and then recover on the the yoga mat. Julia graduated with a degree in journalism in 2004 and spent eight years working as a radio presenter in Kansas City, Vermont, Boston and New York City before discovering the joys of the Rocky Mountains. She then detoured west to Colorado and enjoyed 11 years teaching yoga in Vail before returning to her hometown of Glasgow, Scotland in 2020 to focus on family and writing.