Arc’teryx Atom SV Hoody Review: Warmth for Harsh Alpine Conditions

I've spent a lot of time in my Arc'teryx Atom Hoody and my Atom SL, which is why I'm pumped that the Atom Heavyweight is officially back for fall 2025. Now called the Atom SV , it is the warmest option in the Atom synthetic insulated lineup. Designed for cold alpine hikes, winter layering, and severe mountain weather, it’s built to trap heat, block wind, and layer comfortably under a hardshell. You can get the Atom SV in both the jacket and hoody versions. Here is a comparison from Arc'teryx on the hoody vs. the jacket.

Cost: $300 (jacket) / $350 (hoody) (available now on Arcteryx.com and REI.com)
Fabric: Tyono™ 30-denier Nylon / 20-denier recycled dope dyed nylon ripstop liner
Insulation: Coreloft™ 120 (120 g/m²) - 100% Polyester (80% recycled polyester)
Weight: 455g (men's medium)

Changes from previous version: Fit, side panel insulation, and updated FC0 PFAS-free DWR coating

Yays: The warmest Atom for mid-output activities. Side panels are fully-insulated and breathe better than previous version.
Nays: Lacks dual-zipper for use on belay. Some people may not like the bulkier look compared to the standard Atom.

Keep reading this review for full details and specs on the men's and women's versions of the revised Arc'teryx Atom SV. We also break down how the Atom SV compares to similar insulated pieces from Arc'teryx, including the Proton Heavyweight, and standard Atom. We've separately explored the differences between all the jackets in the Atom and Proton lines. 

We also have an article that looks that the standard Atom and Atom SL.

We're fans of Arc'teryx's Jacket Finder tool to help find the right jacket for your needs. 

Atom SV: What's New?

While the face fabric and type of insulation have stayed the same, the Arc'teryx Atom SV has a few notable updates from the previous Atom Heavyweight. On the outside, Arc'teryx has used their FC0 (PFAS-free) durable water-repellant (DWR) coating. This is in line with their commitment to remove forever-chemicals from their product line. The longevity and care implications of the FC0 coating are more impactful on shells; the only real consideration on the Atom SV is that you will need to refresh the coating when you notice water is no longer beading on the face fabric. It will be plenty weather-resistant. For any extended wet weather you'll want to throw a shell on top. We'd pair this with a Beta jacket and you can read our in-depth look at the Arc'teryx Beta line here.

The more significant changes are on the inside of this jacket. Insulation has been body mapped specifically by gender to improve performance for women and men. Here is how Amber Heath, Senior Designer, Women’s Hike for Arc'teryx describes their design intent - "David, our menswear designer, and I worked closely together to select the ideal fabric and insulation combinations - ensuring optimal warmth for her and reduced humidity buildup for him. This approach allowed us to further refine the designs to meet the specific needs of each gender." Breathability and humidity are things they continually highlight with this updated version and it is clear that a goal for the Atom SV was to improve active performance in cold environments. The side panels actually have more insulation in them compared with previous versions, so this attention to breathability makes sense. I'll cover this more in the sections below.

Atom SV: Materials & Construction

The updated Atom SV makes only small changes in materials from the previous Atom Heavyweight. The updated version features the same Tyono™ 30-denier face fabric. This is a slightly heavy denier fabric from the standard Atom, which uses 20-denier. The difference is in the construction, and specifically the body mapping of the insulation. More on that in my section on warmth below.

The 30-denier face fabric is great for preventing abrasion from backpack straps, harnesses, and backcountry terrain (think rocks and tree branches). On paper the 20d on the Atom vs. 30d on SV may not seem like much, but it is a very purposeful design element.

Weather resistance

Bottom line: The Arc'teryx Atom SV will keep you warm in cold and damp weather. For any extended precipitation it is an excellent mid-layer to be paired with a shell.

The Tyono™ 30 fabric with FC0 DWR is described as resistant to wind and moisture. In practice this jacket excels at keeping you warm in cold and damp weather, but it is not intended to keep you dry for long in the rain. It is however a perfect jacket for enduring cold weather that may feature short periods of snow. As the jacket becomes damp the Coreloft™ synthetic insulation will still perform. Of course, a wet jacket against your skin isn't going to be comfortable. 

Here are two articles we have on the best shells to pair with the Atom SV:

Beta AR vs Beta SL vs Beta: How to decide between Arc'teryx's most popular line of Gore-Tex shells

Alpha vs Beta: Highlighting the different use cases for each

Warmth & Breathability

There is no doubt that the Atom SV is the most insulated in the Arc'teryx Atom lineup and the warmest Atom Arc'teryx has ever produced. The Coreloft™ 120 almost feels like overkill for activities in cool weather if you are working hard. Arc'teryx designer David Kessler highlights activities such as winter hiking and cross country skiing as perfect uses for this jacket. In my experience you are going to roast if you are actually XC skiing with any intensity, but certainly this is a great layer for moderate activity in cold weather. 

That said, I think the updates for fall 2025 are a big part of the story of this jacket. The gender-specific body mapping is a notable improvement. The biggest change I notice is in the side panels on these jackets. The women's Atom SV features a breathable underarm gusset, that is only in the armpit. Since the testing Arc'teryx conducted shows that men put off more heat in this area, the breathable panel extends all the way down to the waste on the men's version. These panels are still insulated, but have a different different fabric that allows more air to escape.

Fit & Feel

The Arc'teryx fit guide is super useful for understanding the different cuts of their jackets, as well as sizing.

The Atom SV uses the Regular fit from Arc'teryx, which means it is roomy through the chest and waist. It allows for plenty of movement and ample baselayer. I usually prefer the Arc'teryx Fitted cut (which wouldn't make sense in a heavyweight jacket), but I think the Atom SV looks great and doesn't feel overly bulky.The upper arms are the only place I point to as being slightly roomier than ideal; this is the only area that feels bulky to me.

The liner on the Atom SV has a brushed feel; it is soft and warms up quickly when putting on a cold jacket. When fully zipped, the neck is cozy without constricting. On the back of the neck there is a flap similar to the wrist cuffs, which prevents cold air and snow from sneaking down your back. It's another design detail that makes this a jacket focused on comfort in harsh weather.

Atom SV: Additional Features

Pockets

The Atom SV gets the standard Atom treatment when it comes to pockets - two zippered handwarmer pockets and an internal, zippered chest pocket that's great for your phone, two-way radio or other communication device.  The handwarmer pockets are fully lined with fleece, which is an important detail on winter jackets that some brands miss. Huge points scored for Arc'teryx on this. I also harp on this in my review of the Stio Hometown Down jacket, since they nail the pockets on that jacket. 

The handwarmer pockets on the Atom SV are placed above the waist, so they are accessible while wearing a pack or harness.

Hood

The hood on the Atom SV Hoody is fully insulated and features a single point of adjustment on the back. It is helmet compatible without being massive, which I appreciate. Using the barrel adjuster on the rear of the hood I can easily keep it out of my face.

Zippers

The front zipper is one-way, which is a little bit of a surprise to me. I would expect that the SV version would get a 2-way zipper for use while belaying. This jacket is not designed specifically for climbing, but it still feels like a miss.

Cuffs

The cuffs on the Atom SV deserve a call out. They are soft and create a nice seal on my wrists, without being too tight. I like these better than a standard elastic binding. 

Bottom Line: Who Should Buy the Arc’teryx Atom SV?

Choose the Atom SV Hoody if:

• You spend time in alpine, backcountry, or sub-freezing environments.
• You need a reliable cold weather midlayer for under a shell.
• You want maximum warmth in a synthetic jacket without moving up to full expedition parkas.
• You want a jacket for your winter daily driver that will still keep you warm in occasional snow.

Skip it if:

• You mostly do aerobic, high-output activities. Pair base layers with a standard Proton, Proton SL, or Atom SL depending on required warmth.
• You want an ultralight, packable synthetic for summer or shoulder season. The Proton SL is better.

Verdict: The Arc’teryx Atom SV Hoody is one of the best cold-weather synthetic jackets for alpine hiking, ski touring, and winter layering. It’s a workhorse midlayer when warmth matters most.

FAQ: Arc’teryx Atom SV Hoody

Is the Atom SV waterproof?

No. It’s water-resistant thanks to DWR but not a shell. Pair with a waterproof hardshell in wet weather.

How warm is the Atom SV compared to the Atom LT?

The Atom SV is significantly warmer, with more Coreloft insulation, making it better for sub-freezing alpine use.

Can I use the Atom SV for skiing?

Yes, especially under a shell. You can use it as an outer layer for skiing in dry weather, but the torso isn't quite long enough for my taste as a dedicated ski jacket. 

Arc’teryx Atom SV vs Proton Heavyweight: which should I buy?

We have a great article that compares the Proton Vs. Atom series, but here is the quick answer when it comes to the new Atom SV:

• Atom SV: Maximum warmth, less breathable, best for cold alpine trips.
• Proton Heavyweight: More breathable, better for active use in milder temps.