Researched & Fact-Checked

How to dry a wet backpack

By Marcus Hale, Lead Pack Research Editor · Published September 14, 2026, 6:03 PM ET

Direct Answer

Dry a wet backpack by turning it inside out where possible, opening every pocket and zipper, and hanging it in a shaded, well-ventilated spot rather than direct sun or a clothes dryer. Stuffing the main compartment loosely with a dry towel speeds drying, which typically takes twenty-four to forty-eight hours depending on padding thickness.

In plain English

A soaked backpack is heavy and floppy, but water itself rarely hurts it. What can hurt it is trying to dry it too fast with heat. A clothes dryer, a heater or a hot car can damage the thin waterproof coating on the fabric and warp the foam padding.

The safe way is slow and simple. Empty the pack, open every zipper and pocket, and hang it upside down or inside out somewhere with moving air, like a porch in the shade or a room with a fan. Stuffing a dry towel inside helps soak up water from the inside.

Think of how a thick winter coat dries after rain. The outside feels dry in a few hours, but the padding stays damp much longer. Packs work the same way, so squeeze the straps and hip belt before you decide it is really dry.

a step demonstrating: How to dry a wet backpack, hands and gear only, no face

A wet backpack — soaked from rain, a stream crossing, or a wash — dries safely with airflow and time, not heat. Heat is the actual risk to a pack's materials during drying, more than the water itself.

Why heat damages a pack while drying

A clothes dryer's heat can melt the glue bonding a pack's polyurethane (PU) coating to its face fabric, causing it to flake or peel over time. The same heat warps foam back panels and hip belt padding out of shape and can crack or discolor plastic buckles, zipper pulls, and sliders. Prolonged direct sun causes slower damage through the same channels via UV exposure, which is why full shade with good airflow is the safer default even though it takes longer than a heat source would.

Man stuffing crumpled paper inside a wet pack in a hall

The drying process

Hang the pack inside out if the construction allows it, with every pocket, main compartment, and zipper open to expose interior surfaces to airflow. Stuffing the main body loosely with a dry towel or two absorbs residual moisture from the inside and helps the pack hold its shape while foam and mesh panels dry.

Pack hung on a fence in weak sun after a rainy trip

Open zippers and pocket flaps with water droplets

Component	Typical dry time	Notes
Outer body fabric	6–12 hours	Dries fastest with airflow on both sides
Mesh back panel	6–12 hours	Dries quickly once suspended and off the body
Foam hip belt/straps	24–48 hours	Slowest to dry; check by feel before storing
Frame sheet/stays	Wipes dry quickly	Remove if possible to speed overall drying

Check the thickest padding — the hip belt and shoulder straps — for lingering dampness before repacking or storing the pack, since that padding holds moisture longest and is where mold is most likely to start if put away too soon.

What the brands say about heat and sun

Every pack maker in our research that addresses drying says to avoid the dryer. Gregory says not to machine wash packs or put them in a dryer because it can damage protective coatings, and to air dry away from heat and direct sunlight with zippered pockets open.¹ REI's general guidance is never to machine dry a pack,² and ULA says never to use a dryer.³ This page's explanation, that heat can loosen the bond between a coating and the fabric, is a reasonable account of how that damage happens, though the makers themselves simply describe it as coating damage.

Sunlight is a slower version of the same problem. REI and ULA both advise drying in shade or indoors because UV light degrades fabric,^2,3 and Nikwax says UV exposure destroys water repellency and reduces fabric tear strength.⁴ A few minutes in the sun won't ruin a pack, but making it a habit wears the fabric down faster.

Knowing when it is truly dry

The dry times in this page's table are rough planning estimates, not measured figures from a source. A humid, still day can double them, and a breezy, dry one can halve them. A more reliable test uses weight. A liter of water has a mass of about one kilogram,⁵ so a pack holding even a cup of water in its foam weighs noticeably more than when dry. Weigh the empty pack on a bathroom or luggage scale when you know it is dry, then check it against that number after a soaking.

Storing it too early is the costly mistake. Deuter recommends keeping packs in a well-ventilated, dry place,⁶ and damp foam in a closed closet is exactly where mold starts.

Drying out on a multi-day trip

On a backpacking trip you can't hang a pack for two days, so the priority shifts from drying the pack to protecting what is inside it. The CDC notes that hypothermia can develop even in cool temperatures above 40°F if a person gets chilled from rain, sweat or cold water,⁷ and the CDC Yellow Book says the priority in cool conditions is staying dry by layering and changing out of damp clothing quickly.⁸

In practice, that means keeping the sleeping bag and a warm layer in a waterproof liner, draining the pack, and turning it so water runs out of the bottom rather than pooling. REI notes that waterproof stuff sacks inside the pack are an alternative to a rain cover and can work better in wind.⁹ The pack can finish drying properly once you are home.