ASIO Late Season Jacket & Bibs Review

I tested the ASIO Late Season Jacket and Bibs during November and January hunts from both a saddle and a mobile treestand. I wore them through cold wind, brush, and long sits where staying warm and quiet mattered more than shaving a few ounces from my pack. This review is based on how the system performed in the tree, not how it felt during a quick try-on.

My field verdict is straightforward: this is one of the warmest and most weather-ready bowhunting systems I have used. It blocks wind well and is quieter than most heavy insulated outerwear. The tradeoff is weight and bulk. This is a warmth-first system for sitting in late-season conditions, not a light jacket for covering miles.

I use the jacket and bibs as my outer LOCK layers. I carry them to the tree, begin the walk comfortably cold, and put them on before I stop moving. That keeps me from soaking my base layers with sweat and gives the insulation a better chance to do its job during the sit.

Who This System Fits

• Good fit: Treestand and saddle hunters who sit for hours in cold wind, hunt the late rut or late season, and carry heavy outer layers to the tree.
• Also good for: Hunters who want a durable, wind-blocking jacket and bib system that can handle brush and rough use.
• Look elsewhere if: You need a light jacket for long hikes, a mild-weather layer, or the absolute quietest fabric for close-range bowhunting. The system is warm because it is substantial.

What I Tested

ASIO sent me the 2.0 Late Season Jacket and Bibs to test. That did not change how I evaluated them. I used the system during November and January hunts, including saddle hunts and mobile treestand hunts. I climbed, walked through brush, sat in the wind, and paid attention to the things that matter once you are actually hunting: warmth, noise, mobility, wind protection, and whether the gear stays comfortable after hours in the tree.

The jacket was also part of my 12 cold-weather hunting jacket study. That larger work uses the same heat-up and cooldown process for every jacket, then puts the temperature data beside insulation, construction, field use, and value. The study is comparative—not a promise that one jacket will keep every hunter warm at the same temperature.

Warmth and Weather Protection

This is a true late-season jacket, not a midseason soft shell with a little insulation added. The jacket uses 180 grams of PrimaLoft Gold insulation. That is why it belongs in the same conversation as other heavy late-season systems, not lighter jackets such as the Sitka Fanatic or First Lite Core.

On the stand, the wind-blocking fabric is the first thing I notice. Wind steals the warm air your layers are trying to hold. The ASIO system does a very good job stopping that heat loss. In cold wind, that protection can matter as much as adding another base layer.

That does not make it a magic jacket. Your base layer, insulation underneath, food, hydration, wind, and how much you sweat on the walk in still matter. I use it as the outer LOCK layer in my Everyday Bow Hunter Clothing System: it traps the warm air I have built underneath and protects it from wind and weather.

Quietness, Mobility, and the Bowhunter Tradeoff

For a heavy, wind-blocking late-season system, ASIO is impressively quiet. I would wash it once or twice before the season. Mine softened up and became quieter with use. It is not as silent as a fleece-focused jacket made only for close-range bowhunting, but it is much quieter than many tough, weatherproof outer shells.

The jacket also gives you enough room to draw a bow without feeling locked up. The tapered collar works well for a bowhunter, and the rear harness opening is useful in a treestand or saddle. The tradeoff is simple: it is a substantial jacket. You feel the protection and insulation. That is a benefit when you are still in the wind and a drawback when you are walking hard.

The Bibs Matter Too

I would not judge this system by the jacket alone. The Late Season Bibs are a big part of why it works on a long, cold sit. They add insulation where you lose it when you are seated, protect your legs from wind, and make the jacket work like a complete late-season system instead of an expensive top layer over the wrong pants.

The full-length leg zippers are especially useful. You can get them on over boots, make quick adjustments at the tree, and avoid turning a cold-weather clothing change into a fight. If you are buying the jacket because you routinely get cold below the waist, the bibs are worth serious consideration.

What I Like

• True late-season insulation and strong wind protection.
• Very good quietness for a durable, heavy outer system.
• Built to handle brush and hard use better than a lighter fleece jacket.
• Good bow-draw room, a useful collar, and a harness opening.
• The bibs complete the system for long cold sits.

What to Consider Before You Buy

• It is heavy and warm. Carry it on the walk in unless conditions are truly bitter.
• There are no pit zips and no hood, so use your layers and pace to manage heat.
• The price makes more sense when you need a serious jacket-and-bib system, not a one-piece solution for every day of the season.
• For the quietest possible close-range bowhunting jacket, look at the Sitka Fanatic. For a warmer, more weather-focused system, the ASIO has a real advantage.

ASIO Late Season Jacket and Bibs FAQs

Is the ASIO Late Season Jacket warm enough for very cold hunts?

Yes, when you use it as part of a complete system. It is a true insulated late-season outer layer, but your layers underneath, the wind, and how much you move still determine your comfort.

Is it quiet enough for bowhunting?

It is very quiet for a heavy, wind-blocking jacket. It is not as silent as the Sitka Fanatic’s fleece, but I felt comfortable drawing and hunting in it after washing and using it.

Should I wear it on the walk in?

Usually no. Start comfortably cold, carry the jacket and bibs, and put them on before you stop moving. That keeps sweat from becoming cold moisture against your body later in the hunt.

Do I need the bibs with the jacket?

You can use the jacket alone, but the bibs make much more sense for long, cold sits. They add warmth where a seated hunter needs it and complete the late-season system.

My Bottom Line

The ASIO Late Season Jacket and Bibs are not trying to be the lightest or most breathable clothes in the truck. They are made to help a bowhunter sit still in cold wind without giving up all the quietness and mobility that hunting demands. If that is your problem, this is a well-built system worth a close look.

Continue the Clothing System

1. Compare the ASIO with all 12 cold-weather hunting jackets I tested.
2. Build the layers underneath your jacket with the Thermal Layering System.
3. Learn why a good jacket may still leave you cold.
4. Use mesh base layers to help manage moisture.
5. Return to the Everyday Bow Hunter Clothing System.