Arc’teryx Atom Jacket (Formerly Atom LT)

I did a pretty good job when I moved to Boulder making fun of how many people wear this Atom Jacket. I mean, it couldn’t be that good such that people wore it that much. Nearly a year ago I bought this jacket for next to nothing when it was being cleared out in this color. I figured worst case I’d use it for rucking or hiking.

Well, I have to say to all those people I mocked: I get it. This is a pretty fantastic jacket.

Specs and Material

All of this info is pulled from Arc’teryx, but I’m packaging it a little differently to help convey everything faster:

Contrast: Circular Knit Fleece, 215 gsm, FC0 DWR — 93% Polyester, 7% Elastane (side panels for increased ventilation)

Body: 20dx20d nylon ripstop, FC0 DWR, 45gsm — 100% Nylon (moisture-resistant outer face fabric)

Synthetic Insulation: Coreloft 60 (60 g/m²) — 100% Polyester (breathable, warm, and light; performs if wet; delivers loft retention that resists packing out)

Lining: Tyono 20, 20d recycled nylon ripstop with FC0 DWR, 40gsm — 100% Nylon (air permeable)

Origin of fabric & dyeing: Japan

Origin of manufacture: Bangladesh

The only thing I struck was “durable” — I’m not sure I buy that, so I’m not going to note it any further. Basically you have a lightweight synthetic insulation layer that packs down okay, but really resists issues with being smashed into a bag and getting wet. It has good wind resistance and okay-ish water resistance. There are two neat tricks on this jacket that are hard to understand until you have one in your hands:

The fleece side panels are really good. They extend up just slightly into the arm so that from your armpit all the way down to the waist you have fleece sides. This stuff breathes really well but doesn’t really allow that much air in from wind. It’s a really neat trick to help the jacket dump heat faster.

The cut on this jacket is exceptionally good. It’s trim — what they call “Fitted.” This is a flattering cut, which also works well if you want to layer a hard shell over the top. It can easily be your outer layer and also a midlayer.

I have a couple of jackets that try to compete with this, but the thought put into materials, placement, and design is vastly superior on the Atom.

In Use

Arc’teryx seems to have nailed what this jacket works well for in their one-liner:

Warm-even-when-wet jacket you can hike, climb, tour, and live in.

My note about this jacket is: I hate how good it is. Mostly because it means I had to eat my mockery of it, as I find myself bouncing around in this jacket a ton. I grab it whenever I’m not sure if it’s cold enough for something, what the weather might hold, or as a just-in-case. I’ll toss on something warmer if I know I’ll need it. I’ll carry something more specific when I’m certain.

The Atom is the jacket I grab when I’m simply not sure what I may or may not need or be facing. It’s really good.

A few thoughts, in random order:

This jacket is incredibly lightweight. When you first pick it up, it’s going to be a little “how is this even possible.” I keep thinking about this because it makes packing it a no-brainer — it doesn’t weigh much at all.

It’s really clever all around. From the cut, to the vented panels, to the cuffs — it works just as comfortably as a midlayer as it does as an outer layer. I can’t say that about a lot of jackets.

I’ve found it fantastically easy to wear, so much so that I can see why people in Boulder somewhat default to this jacket if they own one. It handles the temp swings from sun to shade to wind really well. It’s easy and comfortable.

Around town in cool and cold weather, the temperature regulation is really good. With a heavier shirt under this, I can wear it easily below freezing and still not be sweltering when I pop into a store to do some shopping.

Out hiking, I’ve found this jacket needs to be worn in the low 20s (or lower), as it does build up heat when you’re exerting yourself. Close to the 30s, and I start to overheat quickly when wearing a backpack and hiking.

This is much warmer than something like my Proton SL, which is both good and bad depending on your intended use.

I opted for the jacket and not the hoody variant. I like the look and ease of no hood, but I will note that you can certainly feel the air infiltration around the neck on a windy day. A hood would help seal this neckline, even if not worn. That said, if you hate collars chafing around your neck, this will present no issue.

This jacket is a gem.

It really is a jacket that works well in a city, traveling, or on a hike. I don’t climb or ski, so I can’t comment on those uses. I can say that if I note “cold” on my travel plans, this jacket comes with me. If it’s cold outside and I’m dashing out of the house, I tend to grab this over anything else.

Overall

Where I landed on this jacket is simple: it’s damned good. I might go so far as to say that everyone should own one of these — certainly everyone in Boulder. It’s versatile and can take you pretty far. It’s not my high-output layer, but those hikes are far more rare.

This is my go-to for a warm travel jacket that packs well, for a toss-on when I’m not sure, and for the calmer but cold hikes.

I am a huge fan.

Buy here, $280.