Getting your layering strategy down to science is critical when exploring high mountain peaks, going outdoors during the off-season, or during summer hikes in the mountains. Whether you’re exploring Utah’s high desert or Montana’s northern Rocky Mountains, temperatures are likely to drop far and fast after sunset.
Hailing from British Columbia, an area known for its snowy alpine peaks and grey, rainy weather, Arc’terix often considered the best of the best when it comes to developing lightweight, breathable, insulated layers that wick away sweat while keeping your body warm. The Atom sweatshirt has been around for years and is one of the staples of this warm spirit of weather protection.
i had mine Atom just over six years old and still as strong as the day I bought it (albeit a little stained from too many morning cowboy coffees). It’s the first thing I put in my pack as an extra layer on sunny day hikes in Southern California and a mid-layer to keep me safe and dry when I ski down the slopes or hike the Himalayas. Let’s take a look at what makes this piece so great.
Arc’teryx’s Atom Hoody is a versatile insulated jacket that fits just about anyone, whether you’re heading out on a seasonal day hike, climbing a snowy slope, or enjoying a Pacific Northwest walk. It wicks away light rain with ease and provides breathable warmth for cold-weather cardio workouts. W*rmer than your regular old sweatshirt but lighter than your bulky down jacket, the formfitting Atom with synthetic insulation and stretch fleece panels is available in both styles. Male (named Atom LT Hoody) and female sizes.
Being one of the lightest in its category (10.9 ounces for the women’s model), Atomic sweatshirt offers breathable synthetic warmth for winter uphill walks and off-season excursions when you need an extra layer but don’t want to sweat through your big puff. The outer fabric is soft, durable and highly weatherproof, while intuitive zippered pockets ensure your valuables don’t get lost.

If you live in the dreary Pacific Northwest or love to get outside in snow storms, the Tyono 20 Atom Hoody Waterproof Face Fabric is a real boon for you. It manages to remain wonderfully breathable, allowing rain to collect on the outside of the jacket so you don’t get wet to the bone. On a basic mountaineering course led by an REI expert near Mount San Antonio in California, my group was caught in a mild snowstorm while climbing an icy slope. Others in my group had to stop and pull out their raincoats, but I was happy to see that the Atom hood does a great job of repelling flakes while still staying cozy.
Down is great for many things outdoors, but staying warm in wet weather is not one of them. Weighing 10.9 ounces Atomic sweatshirt rivals many of its down counterparts in terms of weight, and the synthetic insulation is not only vegan, but superbly retains its volume and insulation when the storm rolls in. Attach stretch fleece side panels and you’ve got yourself a comfortable outdoor jacket that breathes where you need it and keeps you warm where it counts.

About a year after I bought my Atom sweatshirt, my zipper broke and broke my heart. The central zipper that made the whole jacket jacket split and didn’t want to close again, ever. Luckily, Arc’terix has guarantee that unless it looks worn and worn, your gear shouldn’t fail due to “practical product life”. So, I took my item to a store in Los Angeles, spoke to a rep, and was able to sew in a new zipper for free. It was good for my wallet and great for the environment.
The brand labels its Atom Hoody as having a “skinny fit,” meaning it’s designed to fit snugly around the body across the chest, waist, and hips, while still allowing natural freedom of movement while climbing or trekking. Personally, I love this design because, unlike my bulky puffer jacket, I can go to the brewery after hanging out with friends and not worry about looking and feeling like a marshmallow.
When the product has been the staple of a well-known brand for more than a decade, the main flaws tend to be corrected and eliminated. That said, there were a few little things we didn’t like about Atom.

Yes, Atomic sweatshirt handles light rainfall (like pesky PNW drizzle or spring snow) just fine, but if you leave it in a heavy downpour for an extended period of time, the Tyono 20’s outer fabric will soak through, leaving you wet. Good news? Because the interior is filled with Coreloft Compact 60 insulation, it will keep you warm even if it gets wet.

I can’t stress enough that this jacket, while insulated, cannot fully handle the warmth of my less attractive down jackets. Of course, I took it with me on a warm July trip through the High Sierras, but only when I knew the temperature would never drop below 45 and I had a great sleeping bag just in case. For four seasons of comfort (or to stay warm on the track), try Atom heavy hoodiewhich is basically the same model with additional insulation, or Padded beta jacket.
Like many Arc’teryx products, the Atom Hoody sits at a higher level of “normal” in its category. If you want to save some money Kuhl’s One padded hoodie and the REI cooperative Flash Insulated Hybrid Hoodie both cost just under $180. For fans of groovy psychedelic colors, Cotopaxi has a bold choice. Teca Calido hooded jacket, for just $150. As with outdoor gear, you often get what you pay for, and the Arc’teryx Atom is lighter and more breathable than other zip-up hoods in its class.

Arc’teryx did it again with Atomic sweatshirt, creating a form-fitting, versatile jacket that can be worn both at home climbing a snowy peak and during an autumn hike in the foothills. It easily shields from the elements while remaining ultra-breathable for cold-weather cardio workouts. Although I wish it were simple touch warmer so I can take it with me on more summer camping trips, it’s still the first thing I put in my everyday backpack at any time of the year to add a cozy extra layer that will stand up to wind, light rain and snow.