Name: Arc'teryx Cerium Hoody
Brand: Arc'teryx

The Arc'teryx Cerium Hoody is stuffed with 3.2 ounces of 850-fill down and features Arc’teryx’s 100- and 80-gram Coreloft synthetic insulation in sweat- and moisture-prone areas such as the cuffs, underarms, and collar. Even as someone who tends to run cold, I found that the jacket kept me sufficiently warm on a month-long trip to Norway’s Lofoten Islands, during which the temperatures consistently dipped into the low 40s Fahrenheit and were accompanied by wind and rain. I usually layered the Cerium over a thin wool base layer and a midweight fleece, and it provided plenty of insulation for taking breaks on exposed peaks or passes. In blustery conditions, it also kept the wind at bay, eliminating the need to layer my rain jacket on top.

Compared to Patagonia’s Down Sweater, which features 4 ounces of 800-fill down in the women’s version (5 oz. in the men’s) and no synthetic insulation, the Cerium felt just as warm while offering better wind resistance. We wouldn’t go so far as to recommend it for exposed belays in frigid temperatures (we’d instead reach for a warmer and more weather-protective jacket like the Rab Neutrino Pro), but the Ceruim is a great standalone piece for shoulder-season conditions or as part of a cold-weather layering system.

Woman smiling wearing Arc'teryx Cerium Hoody down jacket

At just 10.2 ounces for a women’s small, the minimalist Cerium is impressively lofty for its weight. It comes with an attached stuff sack and packs down slightly shorter—yet wider—than a one-ounce Nalgene bottle. While even lighter down jackets exist (the Mountain Hardwear Ghost Whisperer Hoody weighs only 8.5 ounces for a women’s small), the Cerium is in a class of its own in terms of balancing weight, warmth, and features (the aforementioned Ghost Whisperer has thin 10D fabric and less insulation—you can find out more by reading our Ghost Whisperer review). Overall the Cerium is the perfect companion for backcountry trips where you need substantial warmth in a streamlined package.

Arc'teryx Cerium Hoody down jacket stuffed

Arc'teryx Cerium Hoody down jacket stuff sack

The Cerium’s liner is soft on the skin and the jacket offers the coziness I expect from a down puffy. If I had to reach for a comparison, I’d admit that it has a slightly more plasticky feel than a design like the Patagonia Down Sweater Hoody (read our Down Sweater review), although not enough to bother me at all. The Cerium’s fit is a bit slimmer than I’m used to, but it lends itself well to both outdoor activities and everyday wear: The jacket offers great range of movement and the cut makes it easy to layer a base layer or thin fleece jacket underneath. The collar, when fully zipped, is cozy thanks to a fabric fold that the zipper tucks into, and the Cerium’s overall lightweight build makes it easy to wear in a variety of settings.

Woman wearing Arc'teryx Cerium Hoody down jacket while eating

While the Cerium’s 15-denier nylon face fabric is thinner than many of its direct competitors—20-denier seems to be the sweet spot for lightweight down puffies—it held up well throughout my month-long trip in Norway. The zippers and hem are sturdy, and the reverse-coil front zipper (which hides the teeth on the inside) increases durability by exposing less of the zipper to the elements—and it looks snazzy, too. Granted, you can save some money with the Patagonia Down Sweater Hoody ($329), which has more durable 20D fabric, but you sacrifice packability and a lighter weight. So though the Cerium’s $400 price tag can be hard to stomach, it’s hard to find a better balance of weight and durability.

As expected, we encountered a lot of wet weather in Lofoten, which often came down as light sprinkles or mist. If I limited my exposure to less than an hour, the Cerium’s durable water-repellent (DWR) finish effectively beaded moisture and kept it from soaking through the shell fabric. Synthetic insulation in areas like the cuffs and collar provides a second line of defense (unlike down, synthetic fill continues to provide warmth even when wet), but this too will get overwhelmed during prolonged exposures or in truly wet weather. It’s worth noting that the Cerium does not include hydrophobic down, unlike some of the competition (including the Outdoor Research Helium Down reviewed here). All told, the Cerium’s weather resistance is above average for a down jacket, but it should by no means be relied upon in any sort of rain—heavy or light. We always recommend packing a waterproof shell when moisture is in the forecast.

Arc'teryx Cerium Hoody down jacket baffles

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Longevity

Choosing durable outdoor gear is perhaps the most effective way to reduce environmental impact—the longer it lasts, the less it needs to be produced. Our proprietary longevity rating evaluates overall build quality based on factors such as materials, fabric denier, component durability (including zippers and toggles), real-world performance as reported by our field testers, and our experiences with the brand.

Read Sustainability Report

Hood
The Arc'teryx Cerium Hoody has a roomy, helmet-compatible hood that features a simple adjustment cinch at the back. Even without a helmet, this allowed for a snug fit around the head that didn’t restrict my field of vision. And when temperatures dipped, the hood easily accommodated my thick wool beanie and midlayer hood without feeling overly restrictive. Like the rest of the Cerium’s design, the hood is a well-thought-out feature.

Zipping up Arc'teryx Cerium Hoody down jacket

Arc'teryx Cerium Hoody down jacket hood adjustment

Storage
The Cerium Hoody has two hand pockets and an internal chest pocket, all zippered for secure storage. The hand pockets aren’t too large or too small and can hold essentials like a phone, snacks, a beanie, and sunglasses. The internal chest pocket is smaller than average: The zipper opening is 5.5 inches and the pocket is about 8 by 6 inches, but it still fits an iPhone 14. All the zippers operate smoothly, and the pulls have a rubber coating that is easy to grip even with gloves on.

Arc'teryx Cerium Hoody down jacket interior chest pocket

Arc'teryx Cerium Hoody down jacket hand pocket

Tester: 5’3” 103 lb.; 32" chest; 26.5" waist

Size tested: Women’s extra small

I typically wear a women’s size extra small or small depending on the brand, and the extra-small Arc’teryx Cerium Hoody fit me perfectly. The jacket’s slim cut allowed it to rest snugly across my back and shoulders but didn’t significantly restrict movement. (The design doesn’t offer as wide a range of motion as a loose, boxy cut, but this is as expected for a trim jacket.) The back hem reaches nearly to the bottom of the pockets on the back of my pants, providing nice coverage without being too long, while the arm length rests just above the first thumb joint when my arms are relaxed at my side. As a midlayer, the Cerium functions well under a shell without looking too Michelin Man-like or adding unnecessary bulk. A size small would have worked for me too, but the fit would be roomier and the sleeves might have been too long.

Woman standing on rocks wearing Arc'teryx Cerium Hoody down jacket

Rab Mythic G ($525): New-Age Warmth
The Cerium has long been the gold standard for warmth-to-weight ratio among minimalist down jackets, but there’s a new kid in town: the Rab Mythic G. The Mythic G checks in at just 8.9 ounces for the women’s medium—more than an ounce less than the women’s small Cerium—and packs in a hefty 4 ounces of 1,000-fill down. It also features a reflective liner that boosts heat retention. It’s all function here—a shiny lining, a 7-denier shell (noticeably thinner than the Cerium’s 15D material), and minimal adjustments—but it’s worth it for those looking to maximize warmth while keeping their kit at a low weight. However, the Mythic G is $125 more than the Cerium and includes neither hydrophobic down nor synthetic insulation in high-exposure areas, making it more vulnerable to wetting out in moist conditions. For more, read our review of the Rab Mythic G.

Himali Accelerator ($330): Save Some Cash With a Lesser-Known Brand
Himali doesn’t have the same brand cachet as Arc’teryx, but the Colorado-based company knows how to make a lightweight down jacket. For $70 less than the Cerium, the Accelerator has roughly the same amount of down fill and also employs synthetic insulation in exposed areas such as the hood and shoulders. What’s more, its down is treated with a water-repellent finish for even more protection against moisture, and it packs into its own pocket. The Accelerator does add some weight with its thicker (20D) shell, putting it at 11 ounces compared to the Cerium’s 10.2 ounces. But that’s mostly splitting hairs; if you’re willing to take the leap to a new brand, the Accelerator offers similar or better performance and a much better value.

Arc'teryx Cerium Hoody ($400)

Wearing the Arc'teryx Cerium Hoody down jacket during foggy sunset

4.7/5

The Cerium offers extremely lightweight and packable warmth for technical pursuits like alpine climbing and backcountry skiing. Its streamlined fit is ideal for layering, too. However, given the price point, thin fabrics, and trim fit, we don’t recommend this jacket for everyday use.

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Weight

10.2 oz.

Insulation

3.2 oz. of 850-fill down

Fabric

15D nylon

Packable

Yes (stuff sack)

Warmth

3.5/5

Weight & Packability

4/5

Comfort

4.5/5

Durability

2/5

Weather Resistance

2.5/5

Sustainability

4.4/5

Rab Mythic G ($525)

enjoying dinner while the sun goes down in Rab Mythic G Down Jacket

4.4/5

Hold up, what!? We can’t believe Rab managed to pack this much warmth into such a lightweight jacket. You’ll pay a pretty penny for it, and it's unsurprisingly fragile. But the Mythic G is the only sub-10-ounce jacket we know of that can handle freezing temperatures.

Shop Women's Shop Men's

Weight

8.9 oz.

Insulation

4 oz. of 1000-fill down

Fabric

7D nylon

Packable

Yes (stuff sack)

Warmth

3.5/5

Weight & Packability

4.5/5

Comfort

4.5/5

Durability

1/5

Weather Resistance

2/5

Sustainability

3.8/5

Himali Accelerator ($330)

Backpacker wearing Himali Accelerator down jacket

4.4/5

The Himali is a lower-cost alternative to the Arc’teryx Cerium from a niche mountaineering brand. It offers efficient warmth for the weight and added moisture protection thanks to hydrophobic down, a DWR finish on the shell, and synthetic insulation at the collar and under the arms.

Shop Women's Shop Men's

Weight

11 oz.

Insulation

4 oz. of 850-fill down

Fabric

20D nylon

Packable

Yes (pocket)

Warmth

3.5/5

Weight & Packability

4/5

Comfort

4.5/5

Durability

2.5/5

Weather Resistance

2.5/5

Sustainability

2.9/5

Is the Cerium Hoody for You?

The Arc'teryx Cerium Hoody is a stellar choice for folks who are seeking a lightweight, warm, and versatile down jacket. Its balance of comfort, low bulk, and decent weather resistance makes it suitable for a wide range of activities, from hiking and skiing to around-town wear. While the Cerium’s thinner-than-average outer fabric might offer less durability in the long run, the jacket’s standout weight-to-warmth ratio makes it a worthwhile investment. This is a performance-focused down jacket that earns its price tag.