
The differences between Atom SL Anorak (see image) and Atom SL are in the zipper and pocket configurations. Atom SL Anorak comes with a 3/4 zip, and offers only one chest pocket; instead of two side pockets of Atom SL. Apart from this, they're the same piece.
#Note: Full Arc'teryx review list is at the bottom.
For Spring/Summer 2021, Arc'teryx just released a new piece to their Atom line: Atom SL Anorak.
It has been available on MEC.ca (Women's) and also on Bergfreunde.eu for a while now (since early-mid January).
But for the US, the Atom SL Anorak is only available just yet (mid February).
This delay actually isn't exclusive to 2021, and instead, Arc'teryx always seems to be late to release Spring/Summer updates to the US for some reason.
Atom SL Anorak is designed for milder temperatures (chilly spring & summer mornings) where mid to high output activity is expected. It's quite a bit windproof, but offers below average waterproofing.
- Poll results: Giant Arc'teryx & Patagoina survey (Gore-Tex, pockets, hoods, fit, & more) [1000+ participated]
- Pics from outrageous discounts I ran into at Arc'teryx Parndorf Outlet
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- Patera Parka (one year update): Ain't worth the price...
- Alpha vs Beta: I bought all 4 Beta's and both Alpha's. Settling this for good
- Proton Hybrid: A "hidden" way to stuff it in itself!?
- Best Insulated Jackets: A hands-on Arc'teryx & Patagonia face-off
- 2024 Nano Air is in! Bought it immediately...
- I bought all 7 of Winter '24 Atom and Proton jackets
- Best Arc'teryx Ski Jackets: Rush is ideal, Sabre SV is overkill
- Arc’teryx colors: Most and least liked (poll results)
- Took my Nuclei SV to the Alps near Pfander, Austria
- Arc'teryx Alpha Parka Review: The most impressive jacket of all time
- Arc'teryx ReGEAR: OutdoorCrunch exclusive promo code!
- Beta Insulated Jacket is in: Pit zips AND two way zipper
- DropHood vs StormHood: Pros/cons and best uses
- 7 things all Arc'teryx newbies should know
Due to the lack of insulation in the arms (mesh lined sleeves) as well as the minimal amount of insulation in the body, Atom SL Anorak will have breathability in mind when high output activity is the goal.
Canberk is 5'11" and 165 pounds, with an athletic build. Size Medium fits him perfectly across almost all brands and product lines.

Warmth
Among the entire Arc'teryx insulated jacket army, Atom SL and Atom SL Anorak are the ones that offer the least amount of warmth. They offer the lightest density of insulation (Coreloft 40 (40 g/m²)). Arms are NOT insulated.
As you can see, Atom SL is down at the bottom in this table (temperature rating of Atom SL Anorak is identical with that of Atom SL):
Name Activity Temp (F/C) Breathability Weather Res. Durability Bottom line Review Pit zips? Two way zipper? Stuffs into itself? Face Fabric Fit Weight Length Alpha (aka AR) (Men's - Women's) Climbing N/A 8/10 9/10 8/10 4/10 Go-to climbing harshell. Review Yes No No N40d & N80d Most Rugged 3L Gore-Tex Pro Regular 430 g / 15.2 oz 79.5 cm / 31.25 in No Alpha FL (Men's - Women's) Climbing N/A 7/10 No data No data 10/10 No No Yes Hadron 3L Gore-Tex Trim 209 g / 7.4 oz 76.5 cm / 30 in Yes Alpha IS (Men's) Climbing 23/-5 7/10 5/10 No data 8/10 No Yes Yes N40p-X 2L Gore-Tex Regular 610 g / 1 lb 5.5 oz 78 cm / 30.75 in Yes Alpha SL (Men's - Women's) Climbing N/A 5/10 7/10 No data 9/10 No No Yes N40p 3L Gore-Tex Trim 326 g / 11.5 oz 77.5 cm / 30.5 in Yes Alpha SV (Men's - Women's) Climbing N/A 8/10 10/10 10/10 3/10 Strongest climbing hardshell. Review Yes No No N100d Most Rugged 3L Gore-Tex Pro Regular 510 g / 1 lb 2 oz 78 cm / 30.75 in No Andessa (Women's) Skiing 8/-13 10/10 No data No data 1/10 Yes No No N40d 3L Gore-Tex Trim 869 g / 1 lb 14.7 oz 67 cm / 26.4 in Yes Andessa Shell (Women's) Skiing N/A 5/10 No data No data 3/10 No No No N70p 3L Gore-Tex Trim 560 g / 1 lb 3.8 oz ? Yes Beta (Men's - Women's) All Round N/A 6/10 7/10 7/10 8/10 Streamlined all-doer shell. Review No No No N30p-X 3L Gore-Tex Trim 300 g / 10.6 oz 76 cm / 30 in No Beta AR (Men's - Women's) All Round N/A 8/10 9/10 9/10 4/10 Go-to all-round harshell. Review Yes No No N40d & N80d Most Rugged 3L Gore-Tex Pro Regular 460 g / 1 lb 76 cm / 30 in No Beta AR StormHood (Men's - Women's) All Round N/A 8/10 9/10 9/10 4/10 Review Yes No No N40d & N80d Most Rugged 3L Gore-Tex Pro Regular 460 g / 1 lb 76 cm / 30 in No Beta Coat (Women's) All Round N/A 6/10 5/10 No data 5/10 No Yes No 3L Gore-Tex Regular 320 g / 11.3 oz 88 cm / 34.5 in No Beta Down Insulated (Men's) All Round 0/-18 9/10 7/10 8/10 No data Yes Yes No 2L 40D Gore-Tex Regular 760 g / 1 lb 10.8 oz 79 cm / 31 in No Beta Insulated (Men's - Women's) All Round 21/-6 9/10 7/10 8/10 No data Go-to hybrid jacket. Review Yes Yes No N40d 2L Gore-Tex Regular 680 g / 1 lb 8 oz 78.5 cm / 31 in No Beta Insulated Coat (Women's) All Round 16/-9 7/10 No data No data No data No Yes No N40d 2L Gore-Tex Regular 600 g / 1 lb 5.2 oz 86 cm / 34 in No Beta Lightweight (Men's - Women's) All Round N/A 8/10 7/10 7/10 6/10 Review Yes No No N40p 3L Gore-Tex Fitted 380 g / 13.4 oz 75 cm / 29.5 in No Beta Long All Round N/A 4/10 9/10 No data 3/10 Review No No No N80p 3L Gore-Tex Regular 441 g / 15.6 oz 85 cm / 33.5 in Yes Beta LT (Men's - Women's) All Round N/A 7/10 7/10 8/10 6/10 Review Yes No No N40d 3L Gore-Tex Fitted 395 g / 13.9 oz 76 cm / 30 in No Beta LT Hadron All Round N/A 7/10 6/10 4/10 5/10 No No No Hadron 3L Gore-Tex Fitted 255 g / 9 oz 76 cm / 30 in Yes Beta SV (Men's - Women's) All Round N/A 8/10 10/10 10/10 3/10 Strongest all-round harshell. Review Yes No No N80p-X Most Rugged 3L Gore-Tex Pro Regular 495 g / 1 lb 1.5 oz 79 cm / 31 in Yes Cassiar (Men's) Skiing N/A 8/10 7/10 8/10 3/10 Review Yes No No N70p 3L Gore-Tex Trim 820 g / 1 lb 12.9 oz 74.5 cm / 29.3 in Yes Cassiar LT (Men's) Skiing N/A 6/10 6/10 6/10 5/10 Review Yes No No N70p 3L Gore-Tex Trim 605 g / 1 lb 5.3 oz 75 cm / 29.5 in Yes Cita (Women's) Running N/A 7/10 4/10 5/10 10/10 Review No No Yes Lumin Trim 120 g / 4.2 oz 67.5 cm / 26.5 in Yes Cita SL (Women's) Running N/A 7/10 4/10 4/10 10/10 Review Yes No Yes Permeair 20 Trim 65 g / 2.3 oz 61.5 cm / 24.2 in Yes Gamma (aka LT) (Men's - Women's) All Round N/A 7/10 3/10 7/10 3/10 Go-to softshell. Review No No No Wee Burly Double Weave Regular 545 g / 1 lb 3.2 oz 76 cm / 30 in No Gamma SL (aka lightweight) (Men's - Women's) All Round N/A 7/10 2/10 6/10 5/10 Review No No No Fortius 1.0 Trim 310 g / 10.9 oz 74 cm / 29.1 in Yes Gamma MX (Men's) All Round N/A 6/10 4/10 8/10 3/10 Strongest softshell. Review No No No Fortius 2.0 Regular 555 g / 1 lb 3.6 oz 74 cm / 29.1 in No Incendia (Women's) Skiing N/A 8/10 9/10 9/10 3/10 Review Yes No No NP100d 3L Gore-Tex Trim 610 g / 1 lb 5.5 oz 79 cm / 31 in Yes Incendo (Men's) Running N/A 7/10 4/10 5/10 10/10 Review No No Yes Lumin Trim 125 g / 4.4 oz ? Yes Incendo Airshell (Men's Running N/A No data No data No data No data No No Yes ? Trim 105 g / 3.7 oz ? Yes Incendo SL (Men's) Running N/A 7/10 4/10 4/10 10/10 Review No No Yes Permair 20 & Canim Trim 80 g / 2.8 oz 73 cm / 28.75 in Yes Indencia IS Skiing No data No data No data No data No data Yes No No N80p 2L Gore-Tex Regular ? 78 cm / 30.75 in Yes Macai (Men's) Skiing 5/-15 7/10 7/10 6/10 1/10 Review Yes No No N40p-X 3L Gore-Tex Regular 990 g / 2 lb 2.9 oz 75 cm / 29.5 in Yes Macai Lightweight (aka LT) (Men's) Skiing 8/-13 7/10 7/10 6/10 2/10 Review Yes No No N40p-X 3L Gore-Tex Regular 855 g / 1 lb 14.2 oz ? Yes Macai Shell (Men's) Skiing N/A No data No data No data No data Review Yes No No N80p-X 3L Gore-Tex Regular 775 g / 1 lb 11.3 oz ? Yes Micon (Men's) Skiing N/A No data No data No data No data Yes No No N80p 3L Gore-Tex Regular 685 g / 1 lb 8.2 oz 83 cm / 32.5 in Yes Micon Heather Skiing N/A No data No data No data No data Yes No No NP100-d 3L Gore-Tex Regular 685 g / 1 lb 8.2 oz 83 cm / 32.5 in Yes Nodin (Men's - Women's) Running N/A 8/10 5/10 5/10 10/10 No No Yes 20D Tyono Trim 130 g / 4.6 oz 75 cm / 29.5 in Yes Norvan LT (Men's - Women's) Running N/A 5/10 5/10 8/10 6/10 No No No N13p 3L Gore-Tex Trim 190 g / 6.7 oz ? Yes Norvan Shell (Men's Running N/A No data No data No data No data No No No 13D 3L Gore-Tex Trim 190 g / 6.7 oz 73 cm / 28.75 in No Norvan SL (Men's - Women's) Running N/A 7/10 6/10 8/10 8/10 Review No No Yes Gore-Tex Infinium Trim 120 g / 4.2 oz 77 cm / 30.4 in Yes Norvan SL Ins. (Women's) Running 39/4 No data No data No data No data No No Yes Gore-Tex ShakeDry Trim 270 g / 9.5 oz 71.5 cm / 28.1 in Yes Norvan Windshell (Men's Running N/A No data No data No data No data No No Yes Permeair 20 Trim 90 g / 3.2 oz 73 cm / 28.75 in Yes Procline (Men's) Skiing N/A No data No data No data No data Yes No No N70p Gore-Tex Infinium Trim 720 g / 1 lb 9.4 oz 76 cm / 30 in Yes Ravenna (Women's) Skiing N/A 8/10 7/10 8/10 3/10 Review Yes No No N70s-4 3L Gore-Tex Trim 725 g / 1 lb 9.6 oz 69.5 cm / 27.4 in Yes Ravenna LT (Women's) Skiing N/A 6/10 6/10 6/10 5/10 Review Yes No No N70p 3L Gore-Tex Trim 540 g / 1 lb 3 oz 69 cm / 27.2 in Yes Rush (Women's) Skiing N/A 8/10 9/10 9/10 3/10 Go-to ski jacket. Review Yes No No N80p-X & N100p-X 3L Most Rugged Gore-Tex Pro Regular 590 g / 1 lb 4.8 oz 79.5 cm / 31.25 in No Rush (Women's) Skiing 16/-9 3/10 5/10 5/10 9/10 Review No No Yes Hadron 2L Gore-Tex Infinium Regular 515 g / 1 lb 2.2 oz 79 cm / 31 in No Sabre (Men's) Skiing N/A 8/10 8/10 7/10 2/10 Review Yes No No N80p-X 3L Gore-Tex Regular 705 g / 1 lb 8.9 oz 79 cm / 31 in No Sabre AR (Men's) Skiing N/A 7/10 8/10 7/10 7/10 Review Yes No No N70p 3L Gore-Tex Regular 700 g / 1 lb 8.7 oz 79 cm / 31 in Yes Sabre Insulated (See related products) Skiing No data 7/10 No data 6/10 No data Review Yes No No N80p 2L Gore-Tex Regular 815 g / 1 lb 12.7 oz 76 cm / 30 in Yes Sabre LT (Men's) Skiing N/A 7/10 8/10 7/10 8/10 Review Yes No No N80p 3L Gore-Tex Regular 660 g / 1 lb 7.3 oz 83 cm / 32.5 in Yes Sabre SV (Men's) Skiing N/A 10/10 10/10 10/10 1/10 Strongest ski jacket. Review Yes Yes No N100d Most Rugged 3L Gore-Tex Pro Regular 595 g / 1 lb 5 oz 85 cm / 33.5 in Yes Sentinel (Women's) Skiing N/A 8/10 7/10 7/10 2/10 Go-to ski jacket. Review Yes No No N70p 3L Gore-Tex Regular 640 g / 1 lb 6.6 oz 73.7 cm / 29 in No Sentinel AR (Women's) Skiing N/A 7/10 8/10 7/10 7/10 Review Yes No No N70p 3L Gore-Tex Regular 590 g / 1 lb 4.8 oz 72.5 cm / 28.5 in Yes Sentinel Insulated (Women's) Skiing 21/-6 8/10 No data No data No data Review Yes No No N80p 2L Gore-Tex Regular 600 g / 1 lb 5.2 oz 79.8 cm / 31.5 in No Sentinel LT (Women's) Skiing N/A 7/10 8/10 7/10 8/10 Review Yes No No N80p 3L Gore-Tex Regular 565 g / 1 lb 3.9 oz 73.5 cm / 29 in Yes Sentinel Relaxed (Women's) Skiing N/A No data No data No data No data Yes No No N80p 3L Gore-Tex Regular 655 g / 1 lb 7.1 oz ? No Shashka Stretch (Women's) Skiing N/A No data No data No data No data Yes No No N70p Gore-Tex Infinium Trim 670 g / 1 lb 7.6 oz 71 cm / 28 in Yes Sidewinder (Women's) Skiing N/A 8/10 8/10 7/10 2/10 Yes No No N80p 3L Gore-Tex Regular 570 g / 1 lb 4.1 oz ? No Solano (Men's - Women's) Around Town N/A No data No data No data No data Review No No No Gore-Tex Infinium Relaxed 355 g / 12.5 oz 72 cm / 28.3 in No Squamish (Men's - Women's) Running N/A 5/10 4/10 7/10 9/10 Go-to running jacket. Review No No Yes 30D Tyono Trim 140 g / 4.9 oz 77.5 cm / 30.5 in No Theriss Down (Women's) Skiing No data 7/10 6/10 7/10 2/10 Review Yes No No N80p 2L Gore-Tex Regular 709 g / 1 lb 9 oz 63 cm / 24.8 in No Trino SL (Men's) Running N/A 8/10 5/10 7/10 6/10 Review No No No Gore-Tex Infinium Trim 340 g / 12 oz 74 cm / 29.1 in Yes Trino SL Anorak (Women's) Running N/A 8/10 7/10 8/10 7/10 Review No No No Gore-Tex Infinium Trim 290 g / 10.2 oz 65 cm / 25.5 in Yes Venda Anorak (Women's) Around Town N/A No data No data No data No data No No No Gore-Tex Relaxed 255 g / 9 oz 75.5 cm / 29.7 in Yes Zeta AR (Men's) Hiking N/A 7/10 8/10 7/10 4/10 Yes No No 3L Gore-Tex Regular 425 g / 15 oz 80 cm / 31.5 in Yes Zeta FL (Men's - Women's) Hiking N/A 4/10 6/10 4/10 6/10 No No No N20r 2L Gore-Tex Trim 221 g / 7.8 oz 76 cm / 30 in Yes Zeta LT (Men's - Women's) Hiking N/A 5/10 7/10 8/10 5/10 No No No N40P-X 3L Gore-Tex Trim 335 g / 11.8 oz 78 cm / 30.75 in Yes Zeta SL (Men's - Women's) Hiking N/A 3/10 5/10 4/10 5/10 Review No No No 2L Gore-Tex Trim 310 g / 10.9 oz 77.8 cm / 30.6 in Yes
Performance data axis of synthetic jackets (table above) and shell jackets (this table) are different. Don't compare them.
But, since this anorak is designed for high output activities in chilly summer mornings, this isn't (shouldn't be) the main thing to expect from this piece. It isn't, after all, what it's trying to accomplish.
What Atom SL is trying to accomplish is a top-notch breathability, and it does a perfect job with that.
Poll results: Best colorways of Atom Series
Upvote your favorites.

Void

Canvas

Black

Solace

Heritage

Fika/Black Sapphire

Kingfisher

Serene

Black

Canvas

Jungle Maze

Sprint

Solitude

Techno

Atmos

Sprint

Black

Orca

Solace

Fika/Spark

Black Sapphire

Expanse

Velvet Sand

Labyrinth
Quick links:

Wicker/Sprint

Solitude

Groovie

Black

Bliss/Spark

Serene

Black

Solace
Quick links:

Synth

Habitat

Moonlit

Black
Breathability
This is (should be) the main buying point for not only the Atom SL Anorak but also the Atom SL. Tyono 20 outer fabric and fleece side panels of Atom SL Anorak do a pretty good job together to keep you ventilated.
The only reasonable alternative you would have to Atom SL Anorak would be the Proton FL. Proton FL also provides perfect breathability. It's actually even slightly more breathable.
Read my Proton FL vs Atom SL comparison for more information about both.
Weather Resistance
Tyono 20 of Atom SL is quite a bit wind proof. During spring & summer, wind proofing is a higher priority than water proofing when enjoying outdoors. It's especially necessary during any high output activity.
As I explained earlier into the post, Atom SL Anorak is also equipped with a chest pocket, unlike most other Arc'teryx insulated jackets - which are equipped with typical hand pockets.
When this pocket configuration is combined with its superior windproofing capability Atom SL Anorak becomes a pretty good option for climbing folks.
Lastly, although the Atom SL Anorak is less waterproof than its cousins Atom LT and Atom AR (here's my Atom SL vs Atom LT comparison and my Atom LT vs Atom AR comparison); it is, DWR coated.
DWR is a coating. It's basically sprayed on to the surface of these jackets as a finish. It stands for Durable Water Repellent - which means that water will be repelled under wet conditions instead of soaking into the fabric. DWR also decreases dry time. It's a good thing these jackets are coated in DWR. But pay attention to the fact that DWR is a coating - meaning that it will wear off over time. Which is why you might want to invest in a DWR spray such as this one at arcteryx.com for after treatment. As you see, there's a strong correlation between FP x FW and temperature ratings, but not more than, say, 80%. I explained why this happens here in this post of mine.
Fit
Atom SL Anorak fits very trim. Front hem is also longer than that of Atom LT.
Atom SL vs Atom SL Anorak
Atom SL Anorak is exactly the same as Atom SL (Men's - Women's - read my review) itself except for the zipper and pocket configurations.
- Atom SL Anorak comes with a 3/4 zip, and offers only one chest pocket; instead of two side pockets of Atom SL.
And which one would be better for you? Depends.
Unless Atom SL Anorak fits your body type (skinny build) and/or you'll be climbing with this piece 95% of the time...
...then I think I'd get the Atom SL over Atom SL Anorak any day.
Here's a good video review of Atom SL Anorak: