Arc'teryx Thorium AR Down Jacket - Men's
Arc'teryxThorium AR Down Jacket - Men's

Get with the goose down gala in this versatile, lightweight jacket.

What's good for the goose is good for you, and Arc'teryx joins the feather-fete with its Thorium/Cerium family of jackets. The Men's Thorium AR Jacket is a durable, flexible piece combining goose down and Coreloft insulation to meet your winter outwear demands. Wear it to and from the office, hiking to the final summit of the season, or under a shell while blasting through waist-deep powder in single-digit sunshine. Regardless of how you spend your time, the Thorium jacket protects you from the cold, alone or under a hardshell.

  • Innovative insulator for alpine pursuits
  • Synthetic insulated collar and shoulders keep warm when wet
  • Lofty down insulation in the core makes this jacket packable
  • DWR treated shell sheds snowflakes and light moisture
  • Athletic fit with articulated design for freedom of movement
  • Reviews
  • Q & A

Perfect Gift for Dad!

  • Familiarity: I gave it as a gift but have feedback to share
  • Fit: Runs small

We got this as a gift for my wife's dad and he loves it! He primarily uses the jacket for travel, around town, and to the office, but he loves it! We originally got him a Large, but it does fit a little small, so we ended up getting an XL, which fits him perfectly. If you are borderline with sizing, I would go up a size to be safe with this one.

A must not buy

  • Familiarity: I returned this product before using it
  • Fit: True to size
  • Size Bought: Xl

Worst jacket ever bought from Arcteryx and backcountry should be ashamed selling it. The jacket magically unzips by itself and I love Arcteryx closet full of their stuff . Personally backcountry should give a free jacket to anyone who bought this and returned it.

I know man! I hate the way Arc makes some of the zippers that buttery that you sneeze and you unzip your jacket...and they are the "experts" lol


  • Fit: True to size
  • Size Bought: L


Trying to decide between Thorium AR and Cerium LT for hiking/backpacking and travel, I also own the Atom LT but I need something for colder days. What would the temp ranges for these jackets?

Hey Eric, So first -- AR is Arc'teryx way of defining that the jacket is a good "all around" or all purpose jacket. LT stands for Light Weight. The Thorium has 750 grey goose down but the Cerium LT has 850 g white goose down, which essentially results in a lighter weight of filling that still provides just as much warmth. Still, the Cerium LT has 100 g more of insulation, so it is going to be the warmer of the two options. Of course you'll still need a quality base layer depending on where you plan on going, but both jackets are definitely on the warmer side and will certainly keep you warm in single digit temperatures and high winds. Let me know if I can help you find the perfect size!

short torso

  • Familiarity: I returned this product before using it
  • Fit: True to size
  • Size Bought: small

I ordered this jacket for my 14 year old son. Compared with other jackets, this one felt the most durable on the exterior and seems like it would be warm but the torso was shorter than the north face and too short for his 5' 7" frame in a S. A larger size would have been too long in the sleeves.

Lightweight Warmth

  • Familiarity: I've put it through the wringer
  • Fit: True to size
  • Size Bought: Medium

I carried (or wore) a Thorium AR for the entire length of an AT thru hike earlier this year. I used it underneath rain gear, by itself, and slept in it when it was cold. Although I didn't use it for about a six week stretch in the mid-Atlantic states, it came back out in New England, where some of the mountain tops can get pretty chilly, even in July and August. They feel even chillier when you have no body fat left to burn.

The dual construction (down core, synthetic shoulders and extremities) might seem like a marketing gimmick, but it makes total sense in the humid East.

I love this jacket. I'm 5'9, 168 lbs. with a proportionally longer torso and the medium fits perfectly.

This is a garment for serious outdoor use, not urban wear. It's not magic and it won't keep you warm all by itself at -10 Fahrenheit with limited physical exertion. You'll need something a little puffier for that.

Much warmer than fleece under a shell

  • Familiarity: I've used it several times
  • Fit: Runs small
  • Size Bought: XL

I received this jacket for Christmas and have worn it around town and on some backcountry ski trips. I have worn it a fair amount in cold rain under a shell (34-40 degrees) for work outside and it is quite toasty over a long sleeved shirt, standing around and some walking. I've used it as a lunchtime warming layer on ski trips in the Cascades and Olympics and have been impressed with how warm it is. On one summit in the Olympics it was about 25 degrees with a 15-20 mph wind and I was quite comfortable for the half hour lunchbreak (layered over thin fleece and thin long underwear). It is much, much warmer than a 200 wt. fleece jacket and way more comfortable, way more compressible and lighter too. I generally wear a rain shell over it if it is raining because I don't expect it to be waterproof. I was between a Lr and XL at 5'11" and 185 lbs, wearing it over some light layers. If I were only wearing a t-shirt a Lr could work. So the XL is roomy but works for my purpose. I found the fit trim in the shoulders, so I went up a size.

Functional and Aesthetic

  • Familiarity: I've used it several times
  • Fit: True to size
  • Size Bought: XL

I decided to go with the Arc'teryx Thorium AR after much research to try and stay warm in upstate NY.

Fitting: It fits to size. I am generally an XL with most companies, and Arc'teryx does tend to have an atheletic fit. That said, the jacket fits snugly without limiting my movement. I could likely fit a small/thin fleece under and/or layer over it with an overcoat if needed.

Warmth: So far haven't put it through the ringer mid-winter, but it has kept me warm with just a T-shirt underlayer in 20ish degree weather.

Style: As always, Arc'teryx products look good.

I would definitely recommend this jacket.

Not warm enough.

  • Familiarity: I've used it several times
  • Fit: Runs small
  • Size Bought: XL women's

I bought the women's version of this jacket. I was wanting something extremely warm to use for sub zero temperatures. It just recently got cold enough here in Fairbanks for me to test out the jacket. Sad to say, it is not all that warm, even at -10, taking the dog for a walk. It fits rather snugly (yes I bought the right size), so it's not possible to layer, except over, but not under. It's also noisy - gets "crinkly" on some inside layer in the cold, and makes a loud swishing sound when you swing your arms.


Awesome color, lightweight and warm

  • Familiarity: I've used it once or twice and have initial impressions
  • Fit: True to size
  • Size Bought: Large

I'm really happy with the color of this, got the Atlantis green. It's so lightweight and the zippers are really nice and smooth on both the pockets and the main zip. I'm happy with choosing this and haven't used it much yet in 30 degree weather but I'm sure it will meet and exceed my expectations.

No regrets here

  • Familiarity: I've used it several times
  • Fit: True to size

My first Arc'teryx jacket. I purchased this as a new jacket for wearing around-the-town. I am not using it as a technical piece, so I won't be speaking to that.

Let's start off with the look. It looks GOOD. I got it in the Atlatnis Green color and it is amazing. It's really an amazing color. The athletic fit keeps it a little more form fitting, and less boxy, which I prefer. I'm 5'8.5 and about 145. I wear mediums in pretty much all jackets/fleece, and this is no different. I probably could have purchased a small, but I don't think it would have given me much flexibility with what I decide to wear underneath.

Warmth-wise, it appears to do the trick. I have worn it in temperatures ranging from single digits to 35degrees. While I wouldn't say it is a standalone jacket for single digits, it did an admirable job when paired with a good mid-layer fleece.

As to quality. it seems to be typical of Arc'teryx. The only thing I haven't loved is a little loss of down. It isn't anything crazy, just here and there there will be feathers on my shirts and fleece layers. Other down jackets I have owned have lost some feathers, but not as quickly as this.

I love this jacket and would definitely buy again. If you are contemplating purchasing this, I would highly recommend it! It will look good and keep you warm while doing it.

Pretty awesome

  • Familiarity: I've used it several times
  • Fit: Runs large

Overall, this jacket is great. The jacket is super lightweight yet still so warm. The coreloft insulation in the shoulders and collar is a great call, and I still stayed warm when I got rained on unexpectedly. Arc'teryx has done it again, and never fails to impress!

What is the center back length of a medium?

28 inches

Great jacket

  • Familiarity: I've used it once or twice and have initial impressions
  • Fit: True to size

I bought this jacket recently and it met all my expectations. I'm 5'9 150 pounds. The size small fits perfectly. It's warm enough that on most days I just wear a t-shirt underneath. I live in Vancouver, BC.

I'm thinking about buying this for layering under a technical shell while skiing colder days and ice climbing, does anyone have experience using it like this?

Best Answer

Hey Fisher,

In terms of picking an Arcteryx down product that would fit your needs for an active midlayer, the Cerium LT would probably be a better fit for climbing/skiing than the Thorium-- here's a link:

Let me know if you have any other questions-- 1-800-409-4502 ext 4456 or!


As far as skiing colder days, I have used this with only a Baselayer under, and a hardshell on top. That has done just fine. On REALLY cold ski days, this with a light fleece+Baselayer, and a technical shell on top does incredibly well.

Great fit and warm enough

  • Familiarity: I've used it several times
  • Fit: True to size

I got this about 2 weeks ago and have used it a couple of times. Wisconsin falls go down to 30 degrees and I was sweating while biking wearing this.

Which is warmer, this or the Cerium?

Which is warmer, this or the Cerium?

When comparing those two Arc'teryx jackets, I would say the Cerium will be the warmer of the two. This one has an average of 750-fill European goose down where the Cerium is 850-fill European goose down for it's composite mapping. Overall both are solid jackets though!

Best Answer

I have worn both of these jackets, and while I would agree with Jared that the cerium feels a little warmer, I think the difference is pretty negligible.

The real difference between these jackets is a sliding scale of price and weight/durability. The Cerium LT is 8.6oz vs 12.7oz in the Thorium, but you are also paying as much as $60 more.

The Cerium manages to weigh less and have the same warmth because it employs an 850fill down. But if you are not concerned about a few ounces, you put a premium on durability, and you love the sound change makes when it jingles in your pocket, I would favor the Thorium.

The weight truly doesn't matter to me. I just want to stay warm. I expect to use this for skiing and for wearing around town. I just want to warmest thing I can find (I hate being cold), without it being enormously puffy. I'll ski with it under my Arc' Gore-tex shell.

whats gonna be warmer this or my patagonia...

whats gonna be warmer this or my patagonia down sweater and which will last longer the thorium or the cerium

Best Answer


Both the Thorium and Cerium are going to be warmer than the regular Patagonia Down Sweater. The breakdown is Thorium (750fill), PDS (800fill), and Cerium (850fill). However both Arcteryx jackets has a greater fill weight than the PDS and this gives them a strong edge for warmth. Combine that with Arc's new composite mapping that strategically locates synthetic insulation at high-moisture points, and you have two jackets that are very well prepared for adverse conditions.

Fo durability I would favor the Thorium AR which has a 40D face fabric vs 20D in the Cerium. The Cerium is no slouch, but the Thorium will be able to take more of a beating.

Arcteryx Thorium AR

  • Familiarity: I've used it once or twice and have initial impressions
  • Fit: True to size

Fit - In comparison with the Arcteryx Cerium LT Down jacket, I have this in a Medium and the Cerium in a Large and the fit is nearly identical.

Construction - Overall feel is definitely more robust than the Cerium LT (which is how this jacket was designed) including the more heavy duty main zipper. While more robust, it is still fairly light and packable. Will definitely stand up to more rigorous use. Quality is on par with what you would expect from Arcteryx.