Arc'teryx Atom SL Hoody

Engineered as the lightest and most packable member of the Atom family, the Atom SL Hoody is built for high-output days in cold, wet conditions. It delivers focused warmth exactly where you need it—through the core—while uninsulated, mesh-lined sleeves and a low-profile StormHood cut weight and bulk. The result is a versatile midlayer that disappears into a pack yet springs into action the moment the temperature drops.

Breathability is the heart of this design. Stretch Coreloft™ synthetic insulation in the body traps warmth without overheating, while stretchy Octa® fleece side panels improve airflow and freedom of movement. The recycled Fortius Air 20 shell and liner are lightweight, wind-resistant and quick-drying, and a PFAS-free FC0 DWR finish shrugs off light rain and snow. Articulated patterning and an adjustable hem keep the fit precise and drafts out.

Whether you're racking up vertical on an alpine hike, pushing through a cold trail run, or layering under a waterproof shell for mixed mountain pursuits, the Atom SL Hoody adapts to the pace. Hidden hand pockets secure essentials, and the jacket packs down small enough to live in a summit pack. For cold-weather efforts where every gram counts, it's the superlight insulation you'll reach for first.