Serious Warmth Without the Weight

Serious Warmth Without the Weight

When I was a kid in hunting camp with Dad, our jackets were massive. And the fact that we had a crazy amount of layers underneath made them seem even bigger. The thought of pulling off a backpack hunt with that inefficient system was just that, a thought.

Some 25 years later, things are much different. With pieces like the Sitka Kelvin Aerolite Jacket, backpack hunters have it made in the shade. This ultralight addition to your Sitka setup is designed to keep you toasty without adding bulk to your kit.

In short: For backpack hunters looking to cut weight without sacrificing comfort and warmth, the Sitka Kelvin Aerolite Jacket is a no-brainer.

Serious Warmth Without the Weight: Sitka Kelvin Aerolite Jacket Review

  • Outer material
    20-denier polyester
  • Weight
    16 oz.
  • Insulation
    Primaloft Gold, Cross Core, Aerogel

  • Great weight-to-warmth ratio; very lightweight

  • Packable

  • Warm when wet performance

  • Wish the internal pocket was something lightweight, soft, and warm, rather than the outside 20D material

Sitka Kelvin Aerolite Jacket Review


(Photo/Josh Kirchner)

Sitka sought to create a jacket that broke the mold of synthetic pieces. Traditionally, synthetic has always been too heavy and bulky for backpack hunters. Down has always been king when it comes to weight-to-warmth and compressibility.

With that said, when down gets wet, its insulation properties are essentially useless, and it’s extremely hard to dry out. This is where synthetic shines. Synthetics hold their insulation when wet.

So, Sitka took the weight-to-warmth and compressibility of down and combined it with the positives of synthetics. The result was the Kelvin Aerolite Jacket.

The Sitka Kelvin Aerolite Jacket is a hooded synthetic jacket made to insulate you from the cold and disintegrate in your backpack when the temps rise. It’s a static insulation piece for those cold mornings behind the glass.

At just 16 ounces, the Aerolite is a backpack hunter’s dream. Hunters have the choice of seven different sizes (M, L, LT, XL, XLT, XXL, and 3XL) and seven different colors (Optifade open country, subalpine, waterfowl marsh, waterfowl timber, Sitka black, coyote, and storm).

All Kelvin Aerolite Jackets are made with a 20D polyester face and topped with a DWR finish to help repel water. The backing mirrors the face with 20D polyester. Gusseted stretch cuffs aid in putting on and taking off the jacket, as well as not inhibiting shooting. You also have two zippered side pockets and one generously sized zippered chest pocket.


Insulation: Primaloft Gold, Cross Core, and Aerogel

The most impressive thing about the Aerolite Jacket is the insulation. As Sitka puts it, “Air is our best insulator.” And with the Primaloft Gold, Cross Core, and Aerogel (95% air and the world’s lightest solid material), Sitka is able to harness the power of air and keep a full range of motion without the bulk.

Not only that, but this combination delivers the warmth and packability of down with the warm-when-wet performance of synthetics. It’s the best of both worlds.

DWR Coating

(Photo/Josh Kirchner)

While the Kelvin Aerolite Jacket has a warm-when-wet performance, Sitka also added a DWR coating to help shed light rain or snow. This just adds to the efficiency of the jacket and doesn’t send you running for your rain gear right off the rip.


A hood deserves its own section? Yes, it does. This is a form-fitted, low-profile hood that doesn’t block your vision at all. So, when the wind is blowing, your hood isn’t being blown off of your head. It’s a little extra warmth and concealment in a small package that you don’t even notice being on. That is, until you take it off of course.

My Experience With the Sitka Kelvin Aerolite Jacket

(Photo/Josh Kirchner)

Let me say this first. I was worried. When the Sitka Kelvin Aerolite Jacket came in the mail, I immediately started questioning if I was going to be warm or not on my upcoming backpack hunt. Snow was in the forecast with nighttime lows in the high 20s. Let me tell you, that was not a good feeling before my departure.

Sitting here now after going through the whole month of January, those feelings are gone — and gone for good. I don’t say things like this often, but I was blown away by the performance of this jacket. Not once throughout my hunt did I think I was underdressed and it indeed snowed with heavy winds as well.

(Photo/Josh Kirchner)

My full top system that I wore underneath the Kelvin Aerolite wasn’t much either. I wore the Core Merino 120, Ambient Jacket, and Mountain Evo Jacket. That’s it, and I was fine. The fact that this jacket packs down so small, and delivers the performance it does, is much appreciated by me as an avid backpack hunter.

(Photo/Josh Kirchner)

Along with the insulation performance, another thing that really stuck out to me was the hood. One of my biggest pet peeves is a hood that won’t stay on or that I have to work harder to make stay on. The fitted hood of the Kelvin Aerolite is one I literally forgot I was wearing several times. This is in 20-30mph winds.

What’s Wrong?

This is more personal preference than anything because I love this jacket. However, if there was one thing about the Sitka Kelvin Aerolite Jacket that I could change, it would be the internal material of the pockets. As it sits, the material is the same 20D material that makes up the entire jacket.

This is fine, but if there were a very fine, lightweight, and soft material, it would make putting cold hands in the pockets just feel nice. Of course, it would add a smidge more weight, but a guy can dream, right?

Sitka Kelvin Aerolite Jacket: Conclusion

(Photo/Josh Kirchner)

Thinking back to the days of my youth and wearing a silly amount of bulky layers does two things. It makes me smile because those were some fun times. It also makes me realize how good we’ve got it these days with gear like the Sitka Kelvin Aerolite Jacket.

Pieces like this make more possible for backpack hunters like myself. It decreases weight and bulk in the backpack, which means more room for food and more time in the field. It squashes the unfortunate scenario of our down jackets getting too wet because it’s not down. Sitka has flat-out raised the bar in lightweight insulation for hunters with the Kelvin Aerolite Jacket.


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