Cross a windbreaker with an insulated winter coat and you get something like the Arc’teryx Atom SL, a lightweight, weather-resistant jacket.
The Atom SL is available for $229 and is sold as a piece made to provide “thermal regulation” during high-output activities.
We reviewed it for the past four months in all kinds of weather. It proved to be a solid all-around outdoors jacket in not-too-cold conditions.
The insulation is thin — almost see-through — but the jacket is a good defense against the elements in the 40º to 60º F temperature range.
Perfect Cool Weather Jacket
The Atom SL is a light jacket that breathes well, helps shed water (it’s not waterproof), and block wind.
It’s a high-end piece aimed at outdoors athletes like runners and climbers and packs down smaller than a light sweatshirt, all while providing modest warmth and protection from the elements.
Fleece underarm panels and 40 grams of insulation in the torso give the jacket a little warmth. For serious exertion like backcountry touring, this could be a good light shell for uphill skiing on mild winter days.
It sports a “trim fit,” which is slimmer than Arc’teryx’s athletic fit garments and also has a vertical hem drawcord. This means a close fit, excellent for outdoors athletics, but possibly uncomfortable for bulkier individuals.
A new “no-slip zip” prevents accidental unzipping of the jacket and is noticeably more difficult to open with one hand than the one found in the Atom LT, the SL’s big brother. This is nice if you’re running and want to vent with the main zipper; pull it halfway down and the zipper will stay in place.
The arms are lined with a soft-feeling ‘mesh’ fabric that increases breathability and fleece-like sleeve gussets. The face fabric is the new Tyono 20 denier fabric, which feels like a light nylon and is durable for its weight.
There is just enough insulation in this jacket to keep the chill away during cool weather. The thin face fabric allows sweat to evaporate from underlying layers fast, and without condensation.
An un-insulated hood provided protection from biting winds but also allowed heat to dissipate out of the jacket and off our heads. It’s adjustable, making the hood easy to fit over a bike helmet or cinch close to your head.
One thing we would have liked to have seen is adjustable cuffs. Especially in colder temps where we were searching for a tight seal between gloves and the jacket sleeve, there was a lot of room left open for cold air to rush in.
As Insulating Layer
While intended for use as a lightweight outer layer, we feel this jacket could make a good insulator under a shell for ski touring or other winter use.
Thanks to the weather resistant face fabric, it could be worn while skinning uphill in the backcountry, then covered by a more significant jacket when descending or if temperatures drop.
The Atom SL is a versatile piece and could easily adapt as part of a layering system.
Arc’Teryx Atom SL Pricing & Release
From peak-bagging to fall hiking, the Atom SL is a nice insulted wind shell. As noted, it comes at a price of $229, no shocker if you know Arc’teryx’s high-end pricing.
But if you’re in the market for a do-it-all jacket for running, hiking, climbing — really anything active in the outdoors — the Atom SL is right up your alley.