How to waterproof a backpack: four easy solutions

how to waterproof a backpack: hiking in the Lakes
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: Alex Foxfield)

"There's no such thing as bad weather, only inappropriate kit." We'd argue there is such a thing as bad weather, though we do get the sentiment behind this cliched saying. It's getting at the fact that, if you prepare properly with the right gear, a bit of rain shouldn't stop you from exploring the backcountry.

You can repel the worst of the weather and keep yourself dry with a quality waterproof jacket, decent rain pants and a waterproof pair of hiking boots. But, what about your backpack?

The best hiking backpacks are made using water resistant materials and come with double taped seams that are sufficient against light rain. However, even the very best in the business won’t hold up against a proper, sustained downpour. 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

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 four 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)

Meet our experts

Julia Clarke hiking the West Highland Way in the rain
Julia Clarke

Julia has been hiking since her youth, when the Munros of the Southern Highlands were her stomping ground. Having moved to the US for university, she developed her love of the mountains on the Colorado 14ers. Now back in her native Scotland, she knows a thing or two about hiking in the wet , often braving the trails to test kit in proper "dreich" Scottish conditions.

how to waterproof a backpack: hiking in the rain
Alex Foxfield

Alex hates hiking in heavy rain. Unfortunately, having grown up near the English Lake District and having developed a passion for the British mountains, it's a scenario that rears its head all too often. However, as a qualified Mountain Leader, he knows the tricks of the trade when it comes to keeping himself, and his kit, dry. Besides, the wet days make those magical days worth it... Right?

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 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 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. However, the protection doesn't last forever, so you'll need to reproof fairly regularly.

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. Use the pack's 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. Many modern packs have a raincover bundled in, often in a dedicated compartment towards the bottom. 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.

However, this option does have a couple of drawbacks. Firstly, the raincover usually smothers the entirety of your backpack, making it difficult to quickly grab items you may need from its various compartments. 

Secondly, the backcountry is littered with covers that have been caught by the wind, blown away and lost. If you think about it, a raincover doubles up as a rather effective, wind-catching sail, something that often happens when you open it up to pop on your daypack. The challenging conditions that often require a cover to be employed in the first place are exactly the kind of wet and windy conditions that will steal them away. 

So, there's an argument that these kinds of covers end up being bad for the environment, which makes options 3 and 4 more desirable.

3. Use a 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. 

how to waterproof a backpack: hiking in the Lakes

Many mountain professionals opt for option 4, mainly due to its organizational benefits. (Image credit: Alex Foxfield)

4. Use internal dry bags

This option is similar to the pack liner approach but rather than a single waterproof liner, it uses multiple dry bags of differing size. So, while your backpack itself may get a bit wet, all your clothes, electronics, food and maps will be fine.

The big advantage of this approach is organization. For example, if you have several dry bags, you can use one for electronics, one for food, one for midlayers, one for camping equipment and another for items like hats and gloves. Coming up with your own system is half the... fun. Dry bag sets usually come in different colors, so this will appeal to organized individuals who love a bit of color coding.

Julia Clarke

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.  

With contributions from