Arc’teryx Cerium SL Hoody review

Arc’teryx’s lightest down hoody is seriously warm for its weight

Arc’teryx Cerium SL Hoody review

For a winter hike there’s a bit more gear to carry and a thick down jacket soon takes up a lot of that valuable volume in your backpack. 

You have to find that balance between wanting to be warm without carrying too much weight. This is where the Arcteryx Cerium SL hoody from Arc’teryx comes in to its own, with the SL designation referring to Super Light. 

Mens Arc’teryx Cerium SL hoody review

I’ve been wearing one for the past month now, both in day-to-day life and out on the Crianlarich hills in Scotland and it’s surprised me with its warmth for something so thin.

Arc'teryx Cerium hoody review

A cold windy day on Ben Challum was a good test for the Cerium SL

The Cerium SL Hoody is Arc’teryx’s lightest down jacket weighing in at just 215 grams (1.7 ounces). The insulation is ethically-sourced goose down at 850 fill-power, but as you’d expect from a ultralight jacket, there isn’t much put in to the jacket.  

Fabric and warmth

If you’re looking at the Arc’teryx Cerium SL in an outdoor shop, then your first impressions will centre around how it feels to the touch. It has almost a shell-like feel to the fabric and is incredibly thin, to the point where you wonder if it’s actually going to keep you warm. Any doubts I had soon went when I slipped this over my icebreaker baselayer and once the air filled out the down baffles, I was surprised at how warm it was. 

Arc'teryx Cerium SL Hoody review

From L to R clockwise; arrived in a compostable bag, Arato fabric label, how it arrived, baffle design

The exterior is made from Arato 7 nylon and is very wind proof, coping well with the cold gales on my hike. The Arato fabric is almost see-through and you can make out the insulation, particularly if the jacket gets damp. It does have a Durable Water Repellent (DWR) finish though and I could see that water beaded ever so slightly in the drizzle. 

arc'teryx cerium SL hoody review

A perfect hood design

It has a very cool stuff-sack

The cuffs are elasticated and stitched so that they sit flat against your skin, and this stops the cold air getting in. Likewise, there are two hem cords to stop cold air getting up from below. There are two hand pockets, with lightweight zips (no chest or inside pockets). Inside the left pocket there’s a stuff-sack tied in that lets you pack this up small (see below).

A stuff-sack in the left pocket lets you pack the Cerium up super small

Arc'teryx Cerium SL hoody review

The small pack size makes the Cerium SL attractive for trips where weight or volume are important (bikepacking for example)

When you look closer, you’ll notice the cuffs, armpits, shoulders and neck have slightly different fabric. These are areas that are moisture-prone, so they have Coreloft synthetic insulation there. Synthetic down is less likely to absorb moisture than natural down. Be sure to check out my review of the Arc’teryx Atom LT Hoody that has fully synthetic insulation. 

Shoulder area is prone to moisture and rubbing from straps so has synthetic insulation here.

Fantastic hood design

The shape and size of the hood on this is superb.  That hood really does help keep out the cold while letting you have a good range of vision. You can see the elasticated fabric around the edge of the hood, which is similar to what’s on the cuffs. The hood cinch on the back is easy to use with one hand and it’s definitely one of the best hoods I’ve worn.

Arc'teryx Cerium SL hoody review

One of the best hoods for shape and size that I’ve tried

Overall the Arc’teryx Cerium SL has a slim fit and feels snug against my lower back. You can easily wear a base layer and micro fleece underneath it, and then get a shell over the top. If you’re working hard though, you might find it doesn’t breathe too well. If you get a sweat on, the trapped air inside can lead to the down getting damp (wetting out). One of the only potential issues with this jacket might be the thin full-length zip. While designed to be lightweight, I couldn’t help but feel over time that this might be a weak point.

Arc'teryx Cerium SL hoody review

A great investment to have something you know will keep you warm

Price around £300 and available from Arc’teryx


"If you're chasing some weight-saving and like the quality of an Arc'teryx product, then you will love the Cerium SL hoody. It's pricey, but you can rely on it for keeping you warm, despite how light and thin it is. It packs up small and adds so little weight, that you'll be taking this along with you, even on spring/summer adventures. As we mentioned, the Cerium SL doesn't breathe too well, so be mindful of working hard aerobically while wearing it (a fully-synthetic option might be better if you're after something to wear with sustained active use). But as far as ultralight down jackets go, this is one of the best."