Arc’teryx Atom AR vs Atom LT: Which One Should You Buy?

There’s nothing quite like cuddling up next to a campfire under the stars, cozy in your brand new jacket. Arc’teryx has created two spectacular jackets that promise to keep you comfortable: the Atom AR and Atom LT.

The Arc’teryx Atom jackets are designed to be warm, weather-resistant, durable jackets created with synthetic insulation. 

Though the Atom line of jackets was mainly intended to be worn as mid or base layers- meaning with a heavier jacket over the top of them-  they can also be worn as a top layer if the temperatures are right.

If you are looking for the ultimate choice in warmth…

the Arc’teryx Atom AR is our pick for the best  durable water repellent option in this product comparison. 

Made with Coreloft synthetic insulation under a premium, heavier, water-repellent shell, it can certainly keep you warm in the winter even when worn as the winter jacket top layer. 

On the other hand…

…the Arc’teryx Atom LT is a more lightweight, breathable jacket meant to be worn as a mid or base layer in colder months, or as a top layer in the spring or fall.  

While it isn’t as warm as the Atom AR, the Atom LT is a versatile choice that’s much better suited for strenuous hiking trips or other activities when you may get too hot and start sweating.

Read on to see our full comparison of the Arc’teryx Atom AR vs Atom LT winter jackets including:

  • The Arc’teryx LT and Arc’teryx AR features face to face;
  • Their pros and cons;
  • What Arc’teryx works for every trip and adventure;
  • Lots more!


Arc’teryx was founded in 1989 and is based in Vancouver, Canada. The company creates a gamut of outdoor gear, from backpacks and shoes to gloves and jackets, that promises longevity, premium craftsmanship, and functional design. 


…Arc’teryx’s research and development team undergoes field testing in real-world conditions to ensure each product is effective. 

Because they place a high value on outdoor life, Arc’teryx aims to work towards environmentally sustainable, low-carbon-emission practices in manufacturing and daily operations. 

They work to reduce microplastics in their textiles, improve the lifespan of their products, and monitor the company’s environmental impacts all the way from production of materials to disposal.

As if that’s not enough…

…Arc’teryx also gets all of their animal-based materials, such as down, wool, and leather, only through sources that are held to certain certification standards. 

Arc’teryx Atom AR

Arc'teryx Atom AR
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Arc'teryx Atom AR
  • ATOM AR JACKET MEN'S - Significantly warmer and more protective than a fleece jacket, this insulated jacket is breathable enough to be used as a super warm mid layer on frigid days and protective enough to be an outer layer while belaying or hanging out at camp.
  • ARC'ESSENTIALS - Versatile high performance designs for diverse activities and conditions.
  • ATOM - Versatile synthetic insulated mid layers with a high degree of weather resistance.
  • SYNTHETIC INSULATION - Man-made insulation with quick dry times, durability and retains warmth when damp.
  • ALL ROUND - High performance weather protection and materials, emphasizing versatility for multiple activities.

The Arc’teryx Atom AR stands out for its superior warmth and versatility, as it can be worn as either a mid-layer or a top layer, depending on how much warmth you need. 

The jacket is very weather-resistant and performs well in various cold conditions, giving it its namesake: AR (“All Round”).

The Atom AR is constructed with a water-resistant, wind-resistant Tyono 30 outer shell with ventilated “Permeair” panels underneath and arms.

Synthetically insulated with 120 grams/m^2 of insulation in the torso and 80 grams/m^2 in the arms, the AR maintains its warmth even if it comes into contact with moisture. 

In addition to that…

…the jacket’s synthetic insulation has an advantage over a down jacket, which loses its ability to keep you warm if the down becomes wet.

This jacket weighs 425 grams (15 ounces) and is available in three color variations. It comes in sizes S through XXL and has a regular fit style.


  • Insulation has more optimal warmth performance
  • The outer shell is more water- and wind-resistant
  • The outer shell is more durable and premium
  • More effective as a top layer


  • Heavier, bulkier, and more difficult to pack
  • Most probably too warm for spring or fall

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Arc’teryx Atom LT

Arc'teryx Atom LT
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Arc'teryx Atom LT
  • ATOM LT JACKET - This trim hybrid jacket is designed as an active-use insulation layer, providing vital core warmth with liberal mobility and breathability.
  • ATOM LT JACKET - This trim hybrid jacket is designed as an active-use insulation layer, providing vital core warmth with liberal mobility and breathability.
  • ATOM - Versatile synthetic insulated mid layers with a high degree of weather resistance.
  • LIGHTWEIGHT - High performance, minimalist design that is durable for its weight.
  • ARC'ESSENTIALS - Versatile high performance designs for diverse activities and conditions.

The Arc’teryx Atom LT (“LT” for “lightweight”) is a much lighter weight, cozy, soft jacket meant to be worn as a mid-layer or base layer for optimal warmthness. 

Where the Atom LT excels… on the chilly days and nights when you can layer the LT under a warmer parka, or during the more moderate fall or spring temperatures when you can wear it on its own without feeling chilled to the bone.

Like the Atom AR, the LT is constructed with a synthetic Coreloft insulation, specifically Compact 60 insulation. It features 60 grams/m^2 of insulation throughout the jacket.

The Atom LT makes for a great hiking jacket as it can be easily packed away if you get too warm on the trails. Its lightweight, easily compressed body style makes it a perfect fit for a hiking pack.


Atom LT can also be worn as a top layer in milder temperatures, but it would likely not be warm enough as an outer layer for the colder winter months.

The Atom LT weighs 345 grams (12.2 ounces) and comes in size XS through XXXL. It’s available in six different colors and has a slimmer, more trim fit.


  • Lighter in weight than the Atom AR
  • More easily compressible for packing
  • More comfortable as a base layer or mid-layer (less restrictive movement and less chance to overheat)
  • More color options and size variations


  • Not warm enough to be worn as an outer layer in cold weather
  • Fabrics are not as durable and weather-resistant

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Features Face to Face

Weight and Sizes

Weight and Sizes

The Arc’teryx Atom AR, as it is a bulkier, heftier jacket meant for colder temperatures, is heavier at 425 grams

The Atom LT, on the other hand, weighs only 345 grams with its thinner, lighter fabrics.


…the Atom LT can be more easily packed away in a hiking pack or travel bag, as the insulation in the jacket is more compressible. 

The Atom AR, with its thicker insulation and heavier fabric, is harder to compress down to a small size to fit into a more compact hiking bag.

Lastly, the Atom AR comes in sizes small through XXL, while the Atom LT is available all the way from extra-small up to XXXL. 

Because of the Atom LT’s slimmer fit, it’s built to fit your body more closely and precisely, so it’s available in a wider variety of sizes.

Thanks to its more versatile size range…

…as well as its compressibility that makes it simple to pack, and its lightweight style that makes it easy to carry, the Atom LT is the winner of this category.

Outer Fabrics, Durability, and Weatherproofing

The Arc’teryx Atom LT is built with a soft Tyono 20 nylon fabric as its outer shell, meaning it is made with a 20 denier fabric.

On the other hand…

The Atom AR has an outer shell made of Tyono 30 denier nylon fabric. The difference between 20 and 30 deniers means that the Atom AR is built with thicker nylon fibers, leading to less cold air permeation and a higher warmth. 

The higher denier fabric in the Atom AR is also more tear-resistant. Also, the Atom AR’s outer shell has a dura coating for increased durability, making this jacket the longer-lasting option.

This dura coating is a treatment that increases the weather resistance of the fabric- meaning: it will be more resistant to wind and water. 

While the Atom LT has a moisture-resistant outer shell fabric, it is not as waterproof or wind-resistant as the AR’s.

Thanks to its more durable outer shell and higher denier fabrics…

…the Atom AR will have more longevity and durability and keep you chill-free in the rain and wind storms. This gives the Atom AR the edge in this category.

More: The Best Cheap Backpacking Tent: Complete Buying Guide And Reviews

Insulation and Temperature Ratings


Both of these Arc’teryx jackets are constructed with synthetic insulation, which means that they will retain their thermoregulation properties even when wet, making them a more versatile choice than traditional down jackets that lose all ability to retain heat when in contact with moisture. 


…there is still a difference between these two jackets.

Both the Atom AR and LT are insulated with Coreloft. This is a hydrophobic and resilient insulation made of crimped polyester fibers that keep warm air inside the jacket lining.

The Coreloft inside the Atom LT is the Coreloft Compact 60, which is designed to retain loft while still being very lightweight and, as the name implies, compact in size. The Atom LT has 60 grams/m^2 of insulation throughout.

On the other hand…

…the Atom AR is filled with a higher density of Coreloft insulation that is “mapped for optimal thermal performance.” It has 120 grams/m^2 of insulation around the jacket’s upper body and 80 grams/m^2 in the arms. 

The Atom AR also has a drawcord around the jacket’s hem to further trap your body heat and keep you warm.

Because of its higher density of insulation, the Atom AR can keep you comfortable in temperatures down to 10 degrees Fahrenheit, while the Atom LT is suited for temperatures down to 23 degrees Fahrenheit. 

Thanks to its more effective insulation that is sure to keep you warm even on cold winter nights, the Atom AR is the winner of this category. 

However, keep in mind…

…that this doesn’t mean that the Atom AR is appropriate for any situation; in the milder temperatures, the Atom AR will be uncomfortably too warm as a base or mid-layer, and the Atom LT would be an excellent choice.

More: Best Backpacking Chair Reviews: All you need to Know!



The Atom LT is appropriate to wear as a base or mid layer under a warmer jacket in cold winter months.

It can also be worn as an outer layer in milder temperatures, making it quite versatile. 

On the other hand, the Atom AR is slightly less versatile, as it functions best as a top layer in winter or a mid layer in freezing conditions


…it would be too warm as a mid or base layer in most environments that are not frigid.

The Atom LT is the perfect hiking or backpacking jacket, as it isn’t too cold or too hot when on the move. 

The LT would also be the perfect jacket in various other strenuous outdoor adventures where the AR would cause you to overheat, such as snowboarding, biking, and skiing.

Thanks to its more lightweight fabrics and thinner insulation that prevents overheating, the Atom LT is well-suited for a wider variety of activities compared to the Atom AR. Because of this, the Atom LT wins in this category.

More: Patagonia Nano Puff vs Patagonia Nano Air: Which is the Better Jacket to Have?

Comfort and Ventilation

While both of these jackets are comfortable…

…there are differences in construction that make the Atom LT the winner of this category.

The Atom LT is designed with stretch side fleece panels made of 94{6c74ca63e013bf7fdc90f42082e9494ee47031617a282fbe0976712ddae472a0} polyester and 6{6c74ca63e013bf7fdc90f42082e9494ee47031617a282fbe0976712ddae472a0} elastane. These side panels work to make the jacket more breathable, preventing you from sweating uncomfortably.

Thanks to the elastane in the fabric, the side panels also make the Atom LT a high-mobility option, as it allows stretching and more freedom of movement. This leads to increased comfort throughout your day.

More: Your Complete Beginner Guide To Hiking

Standout Features of the Arc’teryx Atom AR

  • Keeps you warmer overall: The Atom AR is appropriate for more frigid temperatures down to 10 degrees Fahrenheit, as it is filled with a higher density of synthetic insulation and has an adjustable drawcord along the hem to keep in your body heat. 

  • More durable outer shell: The 30 denier nylon fabrics in the Atom AR’s outer shell are more durable and rip-resistant than the 20 denier fabrics of the Atom LT. This makes the Atom AR the more long-lasting option of the two jackets.

  • More resistant to the elements: Thanks to the more premium dura coating on the outer shell, the Atom AR will more effectively protect you from moisture and prevent you from getting chilly in the rain or wind.

  • More effective as a top layer: If you want a jacket that doesn’t require a ton of other layers on top of it to keep you warm, the Atom AR is the better choice. It is warm enough to wear as an outer layer with a simple long-sleeve shirt or light jacket underneath it. 

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Standout Features of the Arc’teryx Atom LT

  • More versatile: Because it functions well as a base layer or mid layer, the Atom LT is the more versatile option. Its versatility also comes into play in terms of outdoor activities, as the Atom LT is better-suited for skiing, hiking, and other adventures where the Atom AR would be too warm.

  • More lightweight and packable: The Atom LT is lighter in weight and, thanks to its less dense insulation, it’s more easily compressed into a compact size. This makes it easier to pack away in a hiking pack or small day bag.

  • More well-ventilated: The Atom LT features side panels made out of polyester (fleece) and elastane. These side panels allow for plenty of airflows, preventing you from overheating and getting sweaty in the underarms.

  • Allows for more freedom of movement: Along with preventing uncomfortable underarm sweat, the Atom LT’s side panels are also stretchy. This allows you freedom of movement and comfort on the go.

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Choose the Arc’teryx Atom AR if:

  • You want a jacket designed to be worn as a top layer for frigid temperatures
  • You want the ultimate option in weather resistance against rain and wind
  • You don’t plan to engage in strenuous outdoor activity where you may get sweaty and overly hot

If you’re looking for a jacket that can keep you toasty down to 10 degrees Fahrenheit and protect you from wind and rain alike, check out the Arc’teryx Atom AR.

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Choose the Arc’teryx Atom LT if:

  • You’re looking for a base layer or mid layer underneath a warmer jacket in cold winters
  • You plan to snowboard, ski, or hike long distances in milder temperatures
  • You want the most versatile, comfortable option even if it isn’t the warmest

For a comfortable base or mid-layer jacket that’s suited for the more strenuous outdoor adventures, check out the Arc’teryx Atom LT.

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