In the typical 3-layer ski clothing system, the midlayer is given the all-important insulating duties. As such, it is the one article of clothing you’re most likely to swap out depending on weather conditions. Is it bristling cold and dry? Grab your down jacket. Or, is it a slushy, warm mess? Then a lightweight fleece or synthetic jacket might just do the trick. All three insulation types have their proper applications, and we cover the pros and cons of each in our buying advice and comparison table below the picks. To complete your ski kit, we've also tested and reviewed the best ski jackets and best baselayers.

1. Patagonia Nano-Air ($249)

Patagonia Nano-Air jacket (2017-2018)Insulation: Synthetic
Weight: 12.4 oz.
What we like: Supremely comfortable and excellent breathability.
What we don’t: Not quite as warm as down.

The Patagonia Nano-Air is special: it’s a super soft, stretchy, and breathable synthetic midlayer that feels like a combination of a performance down jacket (minus the down) and your favorite hoodie. The result is a jacket that can be worn as a midlayer for winter sports or as an outerlayer during fall or warm winter days. The stretchiness and breathability make it a favorite among backcountry skiers and climbers, and the soft feel is great for everyday use (we’ve put it through countless days of wear around Seattle).

The Nano-Air can be your Swiss Army Knife layering piece, but keep in mind that warmth is solidly middle of the pack. This is a lightweight synthetic jacket and doesn’t offer the same warmth-to-weight as down fill. And the price is steep compared with newcomers like the Ventrix from The North Face below. Despite these shortcomings, you won’t find a cozier midlayer. We’ve become quite addicted to ours for everything from skiing and snowshoeing to travel. For a more breathable and lighter version of this jacket, try the Nano-Air Light... Read in-depth review
See the Men's Patagonia Nano-Air  See the Women's Patagonia Nano-Air


2. Arc’teryx Atom LT ($239)

Arc'teryx Atom LT jacket (2017-2018)Insulation: Synthetic
Weight: 11.1 oz.
What we like: Great mix of mobility, warmth, and comfort.
What we don’t: Isn’t as breathable as some of the newer synthetic options.

Arc’teryx has built its reputation on legendary shell and insulated jackets, and one of its biggest sellers is the Atom LT. This synthetic jacket is no spring chicken, having been released a number of years ago with only minor updates. Yet the Atom LT remains so popular because it nails the essentials: an excellent balance of breathability and warmth, great mobility, and a just-right cut that fits most folks really well. For these reasons, it’s a top-notch midlayer for both resort and backcountry skiing.

Compared to the Patagonia Nano-Air above, the Atom LT is less breathable with its tough shell and Coreloft synthetic fill (it does have stretchy side panels made with fleece that ventilate pretty well). The Nano-Air also gets the edge in comfort thanks to the generous stretch from its shell and liner fabrics. But we do like the Atom LT’s wind-resistant exterior that allows it to function well as an outerlayer. It’s also more durable than the Nano-Air, showing very few signs of wear over time. For a warmer down midlayer option from Arc’teryx, see the Cerium LT below... Read in-depth review
See the Men's Arc'teryx Atom LT  See the Women's Arc'teryx Atom LT


3. The North Face ThermoBall Full Zip ($199)

The North Face ThermoBall jacket (2017-2018)Insulation: Synthetic
Weight: 12.3 oz.
What we like: Great imitation of a lightweight down jacket.
What we don’t: Boxy fit.

The ThermoBall jacket from The North Face is one of the most popular and heavily marketed synthetic jackets ever. Made in conjunction with synthetic insulation masters PrimaLoft, ThermoBall technology uses small round clusters of PrimaLoft thermal fibers housed inside the jacket’s baffles, giving it the look and feel of a lightweight down puffy (and remember that synthetics insulate much better when wet). It still falls short in terms of warmth for the weight compared to high quality down—just like every other synthetic out there—but is a pretty darn impressive effort overall and the jacket has been a huge success.

Like many products from the North Face, one of our main sticking points with the ThermoBall is fit. We’ve found that it runs rather boxy, which is fine for everyday wear and use as a layering piece at the ski resort (this is exactly what most people are looking for). We still prefer a performance cut in general for better mobility, which is part of the reason why it falls to number 3 on our list despite its more affordable price tag... Read in-depth review
See the Men's North Face ThermoBall  See the Women's North Face ThermoBall


4. Arc’teryx Cerium LT ($349)

Arc'teryx Cerium LT jacket (2017-2018)Insulation: Down & Synthetic
Weight: 9.3 oz.
What we like: Well built and super warm for the weight.
What we don’t: Won’t breathe as well as the synthetic jackets above.

Down offers unsurpassed levels of warmth for the weight, which is clear with a jacket like the Arc’teryx Cerium LT. Weighing in at a feathery 9.3 ounces—one of the lightest midlayers on this list —the Cerium LT is warmer than the synthetics above and packs down small. Despite the mostly down fill, Arc’teryx worked hard to make this jacket capable in wet conditions by mixing in synthetic insulation in areas most exposed to moisture: the shoulders, underarms, cuffs, and collar.

To keep the weight down, the shell of the Cerium LT is made with a thin 20x10 denier fabric. The fabric has a plush feel and we haven’t had any issues with durability, but it will require some extra care to avoid any tears. And given the down fill, the Cerium LT won’t breathe as well as the synthetic options above. It’s a good option for resort skiers in cold places but less so for touring and warmer conditions... Read in-depth review
See the Men's Arc'teryx Cerium LT  See the Women's Arc'teryx Cerium LT


5. REI Co-op Down Jacket ($100)

REI Co-op Down Jackets (2017-2018)Insulation: Down
Weight: 10.5 oz.
What we like: Great value for a down jacket.
What we don’t: Less of a performance option.

For those looking for a down jacket on a budget, we love the REI Co-op. It’s a simple jacket that lacks the fit and finish and just-right cut of a Patagonia or Arc’teryx product, but it’s an undeniable value. At $100, it can still go head-to-head with down sweaters that are double the cost from brands like Columbia and Marmot.

Keep in mind that the REI Co-op isn’t a serious performance piece and is best for causal use and layering. The 650-fill down is a lower quality than the Cerium LT above, although it’s still superior in warmth-to-weight than most synthetics. In addition, this jacket lacks a hem adjustment, which is limiting for dialing in fit. However, for daily use, travel, and as a midlayer for resort skiing, you just won’t find a better deal. As an added bonus, the Co-op stuffs down into its left-hand pocket, making it easily packable... Read in-depth review
See the Men's REI Co-op Down Jacket  See the Women's REI Co-op Down Jacket


6. Patagonia R2 Fleece ($169)

Patagonia R2 Fleece (2017-2018)Insulation: Fleece
Weight: 14.3 oz.
What we like: The ultimate athletic fleece.
What we don’t: Limited water resistance (no DWR treatment)

In terms of performance fleeces, it’s tough to beat Patagonia’s R series. With three models of varying warmth to choose from, our top midlayer pick is the R2, which hits a nice middle ground of warmth and breathability. This jacket is a hybrid of two types of fleece: a cozy high-loft fleece around the body and arms, and Patagonia’s more breathable and lower profile R1 fleece under the arms and along the sides. The combination nets plenty of warmth for days at the resort but is great for movement and won’t overheat should you venture off trail.

We also like fleeces as midlayers in terms of value. Patagonia apparel isn’t cheap in general, but the R2 at $169 is a nice step down in price from the synthetic and down jackets above. The major downside is that this jacket (and fleeces in general) will not block wind, which limits its utility as an outerlayer. Remember to carry a shell in inclement weather, but when using the R2 as a midlayer, you’ll be just fine.
See the Men's Patagonia R2 Fleece  See the Women's Patagonia R2 Fleece


7. The North Face Ventrix ($199)

The North Face Ventrix JacketInsulation: Synthetic
Weight: 14.8 oz.
What we like: Nano-Air comfort and fit for $50 less.
What we don’t: Not everyone will appreciate the technical details.

As with Patagonia, The North Face is synonymous with cozy layering pieces. Their newest synthetic jacket, the Ventrix, takes direct aim at the Nano-Air above with a super soft liner and shell, along with insulation that puts a premium on breathability and temperature regulation. It falls a little short of the Nano-Air’s pillow-like feel, but the Ventrix costs $50 less and is a little warmer to boot.  

Most products made by The North Face have a casual slant—including the ThermoBall above—but the Ventrix unquestionably is a performance piece. The jacket has a more athletic cut than the Nano-Air, and includes technical features like tiny holes under the arms for venting and panels of higher denier fabric on the forearms. But we give the edge to the Nano-Air as a midlayer: it essentially matches the Ventrix in terms of performance without all the fuss, not to mention its clean styling wears better around town. But if you like the techy look and fit, the Ventrix is a similar concept as the Nano-Air for less... Read in-depth review
See the Men's North Face Ventrix  See the Women's North Face Ventrix


8. Outdoor Research Ascendant ($199)

Outdoor Research Ascendant jacketInsulation: Synthetic
Weight: 11.7 oz.
What we like: Light, breathable, and a great value.
What we don’t: Hand pockets don’t have zipper closures.

Outdoor Research jumped into the high-output synthetic market a few years ago with the Uberlayer, but it never fully clicked with us: it was too heavy, didn’t pack down well, expensive at $299, and only came in a hoody design. For this season they’ve released the Ascendant, which addresses each and every complaint. By removing the inner liner and simplifying the feature set, the new jacket is a feathery 11.7 ounces and priced very competitively at $199. And for midlayer use, we love the addition of a standard, non-hooded jacket.

Where could the Ascendant be improved? We value the focus on cutting weight, but we think they took it one step too far by making the hand pockets without zippered closures (the chest pocket is zippered, however). Also, more time with the jacket will tell if the exposed insulation on the interior starts to wear and even break down with heavy use. Early impressions are strong, however, and we think the Ascendant is a great addition to the active insulation field.
See the Men's Outdoor Research Ascendant  See the Women's Outdoor Research Ascendant


9. Patagonia Down Sweater Vest ($179)

Patagonia Down Sweater Vest (2017-2018)Insulation: Down
Weight: 9.8 oz.
What we like: Warmth where need it most.
What we don’t: Less versatile as an outerlayer.

We all know by now that down is the warmest and most packable insulator, but for midlayer use in moderate conditions, a full down jacket can be too much. Enter the Patagonia Down Sweater Vest, which will provide ample warmth around your core without overdoing it. Like the popular full jacket version, the Vest uses premium 800-fill down, has excellent build quality, and looks great, too. And the vest weighs only 9.8 ounces, a nice 3-ounce drop from the jacket.

We love this vest for wearing under a shell or even as an outerlayer for winter hiking and snowshoeing on a clear day. And of course, vests are great for casual wear in the fall and spring. One final piece of advice: if you go with a vest for a midlayer, make sure to choose a warm and comfortable baselayer. Obviously it matters more with your arms exposed.
See the Men's Patagonia Down Sweater  See the Women's Patagonia Down Sweater


10. Black Diamond First Light ($229)

Black Diamond First Light JacketInsulation: Synthetic
Weight: 16.6 oz.
What we like: Warm and breathable with a tough shell fabric.
What we don’t: Heavier than the options above without a boost in warmth.

Last winter, we tested and came away impressed with the Black Diamond First Light Hoody, and they’ve added a standard non-hooded version for 2017-2018. The good news is that the new style shares the same performance attributes with breathable PrimaLoft Silver Active insulation and a stretchy shell. More, among high-output synthetic options, the First Light’s Schoeller exterior fabric is tougher and offers superior protection against wind and moderate precipitation.

We love the First Light Hoody for use primarily as an outer layer for climbing and backcountry skiing, but are a little less enthusiastic about the standard jacket. To start, the stout shell isn’t necessary when worn as a midlayer, and the 16.6-ounce weight is among the heaviest on our list. More, you’re not getting any extra warmth with its 60-gram fill. If the First Light were priced closer to the Ventrix above, it could very well move up our list, but at $229 it ends up with a midpack finish... Read in-depth review
See the Men's Black Diamond First Light  See the Women's Black Diamond First Light


11. Marmot Featherless Jacket ($175)

Marmot Featherless jacketInsulation: Synthetic
Weight: 12.3 oz.
What we like: Down-like insulation and comfort.
What we don’t: Light on warmth.

On the heels of the ThermoBall’s success is Marmot’s entry into the down-like synthetic market. Their new Featherless lineup uses 3M’s Thinsulate in a loose-fill design to give the jacket the puffy look and feel of natural down clusters. Marmot makes a range of Featherless options, but we like the entry-level standard jacket, which is lightweight at about 12 ounces and undercuts the ThermoBall by $24. For casual use or layering under a ski shell at the resort, the jacket is well worth a try.

What are the downsides of the Marmot Featherless? The sheer number of baffles and stitch-through design leave a lot of vulnerabilities for cold air to seep in. And for active use, the slippery shell and liner can’t compete with an option like The North Face Ventrix in terms of breathability and stretchiness. But down jackets suffer from similar issues, and the Featherless’s $175 price and typical Marmot quality make it an interesting budget alternative to a down jacket.
See the Men's Marmot Featherless  See the Women's Marmot Featherless


12. Dynafit Radical 2 PrimaLoft ($240)

Dynafit Radical 2 PrimaLoft jacketInsulation: Synthetic
Weight: 14.5 oz.
What we like: A quality mid and outer layer for ski touring.
What we don’t: Slim cut isn’t for everyone.

Dynafit is best known for their innovative backcountry ski bindings, so it shouldn’t come as a surprise that their apparel line is equally focused on the ski touring world. The new Radical 2 PrimaLoft jacket is designed with the uphill in mind, with a wind and water resistant shell, stretch panels, and PrimaLoft Silver Active insulation. And unlike most jackets that come in a hoody design, the Radical 2 layers easily under a shell with its very snug fit and low profile hood.

The focused outdoor design is fantastic for its intended use on the skin track, but the Radical 2 is one of the least-friendly jackets on this list for everyday wear. The trim cut is uncomfortable around town, lacking the balance that we love from an option like Patagonia’s Nano-Air. More, at a premium $240 price, we would have liked to see PrimaLoft’s high-end Gold Active insulation rather than Silver. Nevertheless, you’ll be hard-pressed to find a better hooded midlayer that won’t get in your way in the backcountry.
See the Men's Dynafit Radical 2 PrimaLoft  See the Women's Dynafit Radical 2 PrimaLoft


13. Black Diamond CoEfficient Fleece ($149)

Black Diamond CoEfficient jacket (2017-2018)Insulation: Fleece
Weight: 12.3 oz.
What we like: A hi-tech fleece suitable for a variety of activities.
What we don’t: Not super warm.

Not everyone needs a whole lot of insulation on the mountain, and for ski touring and milder days at the resort, we recommend the Black Diamond CoEfficient. Featuring Polartec Power Dry High Efficiency fleece, the CoEfficient is surprisingly lightweight and has good warmth for its thin profile. Most importantly, it offers breathability that surpasses even the best synthetic and down options. It’s a spot-on choice for those looking for a lightly-insulated performance midlayer (BD specializes in performance and this jacket is very popular among the backcountry crowd).

Aside from midlayer use, we love the versatility of the CoEfficient. The athletic fit and breathability work well for rock climbing, hiking, and biking, and the jacket has plenty of length in the arms to retain good coverage for all of those activities. More, the shell fabric dries out really quickly, so if a quick shower passes through, you should be comfortable again in short order. Overall, if you like to work up a sweat and need a midlayer to match, the CoEfficient Fleece is a nice choice... Read in-depth review
See the Men's Black Diamond CoEfficient  See the Women's Black Diamond CoEfficient


14. Montbell Plasma 1000 Vest ($229)

Montbell Plasma 1000 VestInsulation: Down
Weight: 3.1 oz.
What we like: Unbeatable weight and packability.
What we don’t: Very thin shell fabric.

Montbell’s Plasma 1000 Vest can be summed up with two specs: 1,000-fill power down and a 3.1-ounce total weight. Starting with down fill, we consider 800 fill power to be premium quality, 900 is only offered from a few select companies, and 1,000 fill is nearly unheard of and just silly in terms of warmth to weight. And at 3.1 ounces all-in, the vest gives your core a surprising amount of cozy warmth at a weight that will make even the most discerning minimalists happy.

The very thin 7-denier shell on the Plasma 1000 is protected when worn as a midlayer, but it’s still a significant downside of the vest. Not only is the material crinkly when moving around, but it’s too delicate to trust without a shell on most outdoor adventures. And even though the warmth-to-weight ratio is fantastic, the vest’s minimal 1.1 ounces of down only provides a modest amount of insulation. For extra warmth there is a Plasma 1000 jacket, which is viable for most summer backpacking and climbing trips, but that weighs a “hefty” 4.8 ounces.
See the Men's Montbell Plasma 1000  See the Women's Montbell Plasma 1000


15. Smartwool Corbet 120 Jacket ($200)

Smartwool Corbet 120 jacketInsulation: Synthetic (wool blend)
Weight: 15.8 oz.
What we like: Functional wool insulation and athletic fit.
What we don’t: Pricey and wool insulation isn’t all that warm.

Similar to the Patagonia Down Sweater Vest above, the Smartwool Corbet 120 gives you warmth where you need it and flexibility where you don’t. We really like what Smartwool has done with this design, which includes a merino wool liner, SmartLoft 120 wool insulation, and a nylon exterior. Throw in a DWR finish and the result is an active midlayer, outerlayer (and even baselayer) that is super comfortable, agile, and regulates your body heat quite well.

If you’re the type that runs cold, this probably isn’t the midlayer for you. Wool is a good insulator and does a great job at not retaining moisture or stink, but even the 120-gram fill isn't all that warm for the weight. But we still appreciate the design, which is very functional compared to traditional jackets that are uniform in materials and thickness throughout. And a couple bonuses: you can run, hike, and bike in this jacket in cool conditions, and it looks great.
See the Men's Smartwool Corbet 120  See the Women's Smartwool Corbet 120


16. Mountain Hardwear Monkey Man ($160)

Mountain Hardwear Monkey Man jacket (2017-2018)Insulation: Fleece
Weight: 14 oz.
What we like: Fuzzy and comfortable, yet very functional.  
What we don’t: Polarizing looks.

The Monkey Man is an excellent performance fleece and one of our all-time favorite pieces of gear from Mountain Hardwear. First, it’s one of the softest jackets not just on this list but in general, made with the Polartec's signature High Loft fabric. Aside from the high loft, this is not your bulky and casual fleece of yesteryear: it’s a slim-fitting piece that has built-in elastane for a forgiving stretch.

In terms of insulation, the Monkey Man is on the thin side and has clearly been designed with midlayer use in mind. The open weave construction of the Polartec High Loft freely lets air in and out, which contributes to both excellent ventilation and little protection from the wind. And for the weight we’d prefer a bit more warmth (synthetic and down options are far warmer), but it remains a solid midlayer option for winter sports.
See the Men's MH Monkey Man  See the Women's MH Monkey Woman


17. Columbia Steens Mountain 2.0 ($60)

Columbia Steens Mountain Full-Zip fleece jacket (2017-2018)Insulation: Fleece
Weight: 17 oz.
What we like: Inexpensive and surprisingly comfortable.
What we don’t: Very basic and durability is questionable.

Simplicity is the name of the game with the Steens Mountain 2.0 from Columbia, but that’s not necessarily a bad thing. Soft, inexpensive, and offered in a ton of sizes and colors, this is an extremely popular budget fleece. For about $60 (or less on sale, which it frequently is), you get a midlayer that offers a decent amount of warmth and a reasonably comfortable fit.

What are the shortcomings of going so cheap? The materials are quite basic and you don’t get any features to speak of. It also won’t last as long as the higher-end fleece options above, so don’t expect it to be your workhorse for years to come. But if you’re looking for an inexpensive layering piece for the occasional weekend trip, the Steens Mountain should get the job done.
See the Men's Columbia Steens Mountain  See the Women's Columbia Benton Springs


Midlayer Comparison Table

Jacket Price Type Insulation Weight Packable
Patagonia Nano-Air $249 Synthetic 60g FullRange 12.4 oz. No
Arc’teryx Atom LT $239 Synthetic 60g Coreloft 11.1 oz. Yes
The North Face ThermoBall $199 Synthetic 33g ThermoBall 12.3 oz. Yes
Arc’teryx Cerium LT $349 Down/Synthetic 850-fill down; Coreloft 9.3 oz. Yes
REI Co-op Down Jacket $100 Down 650-fill down 10.5 oz. Yes
Patagonia R2 Fleece $169 Fleece Polartec ThermalPro 14.3 oz. No
The North Face Ventrix $199 Synthetic 80g Ventrix 14.8 oz. No
Outdoor Research Ascendant $199 Synthetic 95g Polartec Alpha 11.7 oz. Yes
Patagonia Down Sweater Vest $179 Down 800-fill down 9.8 oz. Yes
Black Diamond First Light $229 Synthetic 60g PrimaLoft Silver 16.6 oz. Yes
Marmot Featherless Jacket $175 Synthetic 3M Thinsulate 12.3 oz. Yes
Dynafit Radical 2 PrimaLoft $240 Synthetic 60g & 80g PrimaLoft Silver 14.5 oz. No
Black Diamond CoEfficient $149 Fleece Polartec PowerDry 12.3 oz. No
Montbell Plasma 1000 Vest $229 Down 1,000-fill down 3.1 oz. Yes
Smartwool Corbet 120 $200 Synthetic (wool) 120g SmartLoft 15.8 oz. No
Mountain Hardwear Monkey Man $160 Fleece Polartec ThermalPro 14 oz. No
Columbia Steens Mountain 2.0 $60 Fleece MTR filament fleece 17 oz. No


Midlayer Buying Advice

Midlayer Insulation Types

A skiing midlayer classic, the fleece jacket is a comfortable and affordable way to stay warm. In spite of what the name may indicate, fleece (or polar fleece) is a wholly manmade synthetic made up of petroleum products. Many new models are made of plastics such as recycled bottles, and through a rather impressive process, out spits a cozy and soft fleece. These jackets are wonderful as a midlayer for skiing thanks to their ability to resist absorbing moisture and fast drying time. Additionally, cost is a big reason for choosing a fleece, even if they do have a tendency to pill up over time.

In terms of warmth, fleece jackets are most often measured in terms of fleece weight. A 100-weight fleece—also referred to as lightweight, R1, or others, depending on the brand—is a thin and lightweight option that breathes very well but isn’t as warm. These are great for mild weather skiing or backcountry skiers. 200-weight is the classic midweight and is the most popular choice, including the Mountain Hardwear Monkey Man and Patagonia R2 above. It’s warm enough for most cold days but has less of a tendency to overheat like the 300-weight option. Those heavyweights are for the truly cold days on the slopes—unless you’re someone that’s constantly cold.

Midlayers (fleece)
Black Diamond's CoEfficient uses a gridded Polartec Power Dry fleece

Synthetic Insulation
Opting for a synthetic jacket will most often involve a slight step up in terms of cost from a fleece but comes with reduced bulk and a more stylish quilted appearance. And as an upgrade from down fill, synthetics continue insulating when wet. Mid and high-end synthetic jackets have become synonymous with a single name: PrimaLoft. This brand of thermal insulation has taken off in recent years thanks to their microfiber design that heats very efficiently—even if it still falls short of down-fill. Recent trends in insulation have placed a big emphasis on breathability, including the impressive FullRange insulation used by Patagonia in their Nano-Air jacket. Combined with a breathable shell, the Nano-Air is a fantastic midlayer for active resort or backcountry skiers.

Synthetic insulation is measured in grams, which is how much insulation a 1 x 1 meter section of the fibers weigh. Lightweight synthetics will have approximately 40 to 60 grams of insulation, and midweights are closer to 100 grams. Once you reach the midweight category, you are dealing with a very bulky jacket, which is why the 60-gram choice is so popular. It’s light and easy to move in, making it perfect as an all-around ski midlayer.

Patagonia Nano-Air midlayer
Our top-rated Patagonia Nano-Air worn under the Arc'teryx Rush ski shell

Down Insulation
The synthetic options above have never been able to match the heat retention of natural goose or duck feathers. There is simply no better way to stay warm than a down jacket as long as you avoid heavy moisture—down will clump up and stop insulating when wet. If you really make an effort to stay dry with a bombproof shell, or for dry and cold conditions like Utah, Colorado, or parts of the East Coast, a down jacket is a perfect fit. On positively frigid days, an option like the venerable Patagonia Down Sweater remains a go-to choice.

In comparing down jackets, the two most important specifications are down fill-power and fill weight. These are two independent measurements, but taken together they will give you an indication on how warm the jacket will be. To start, fill-power is a measurement of the quality of the down clusters. Because down relies on loft to trap heat against your body, a jacket that requires fewer clusters to achieve the same amount of loft will be equally as warm but weigh less. As a result, you pay more for a higher fill-power. Mid-range fill-power falls in the 550-650 range, and high-end jackets will have 700+, reaching as high as 1,000 for some brands like Montbell. Fill weight is the next metric, and this is simply the total amount of down in the jacket, given in ounces. Now remember, weight isn’t the only indicator and should be looked at alongside the fill power, but it remains a very helpful number in figuring out jacket warmth.

Down Insulation (Patagonia Down Sweater)
The Patagonia Down Sweater uses high quality 800-fill down

Important Strengths and Weaknesses

Your preferences on warmth will depend on a number of factors, including where you ski and the conditions you’re willing to go out in, as well as considerations like if you use an insulated ski jacket or just a shell. Warmth will vary no matter the choice, but the most efficient heater is the down jacket. The clusters of feathers offer unmatched warmth relative to the weight of the garment. And choosing a higher fill-power option will have the best warmth-to-weight ratio.

Next in line is synthetic insulation, which is sometimes referred to as a synthetic down because it was designed to emulate the heat capturing abilities of the duck or goose clusters. While not as efficient in heating for the weight, synthetic jackets are still a great choice for skiing in typical resort conditions.

Arc'teryx Atom LT and TNF ThermoBall comparison
Both the Arc'teryx Atom LT (left) and ThermoBall (right) are warm enough for most ski days

A fleece jacket may be at the bottom of our warmth list, but it’s not to say you can’t find a very warm fleece coat. It just takes a lot of fleece to get you there. And for many skiers (us included), a bulky jacket can interfere with the fun, which puts fleece at the bottom of our warmth scale.

Down: Excellent
Synthetic: Very Good
Fleece: Good

Snow and Wet Weather Protection
This category is where the down jacket struggles in relation to the other two. If your down jacket is poking out the bottom of your shell and you plant yourself in some wet snow (the Pacific Northwest variety comes to mind), the jacket’s ability to insulate will be compromised. One of the appeals in moving to a synthetic insulation is the fact that it is still able to retain some insulating properties when wet. And although synthetic jackets will easily outperform down—even the new hydrophobic down variations—fleece remains top of the class. This is due in part to the naturally hydrophobic nature (well, as natural as a manmade plastic can be) of the polyester construction. But what helps give fleece the edge in this category is its ability to dry much faster than the synthetic fibers.

Fleece: Very good
Synthetic: Good
Down: Not good (even hydrophobic down falls short)

Breathability is another strong suit of fleece jackets and synthetic insulation. Overall, we give the edge to fleeces, which are naturally porous, and new models that have built-in stretch open up even more avenues for hot air to escape. But, as we mentioned above, products like Patagonia’s Nano-Air are pushing synthetic jackets well into the high performance world. Unfortunately, down jackets are on the outside looking in here. Their supreme warmth retention doesn’t breathe nearly as well as the other two options.

Fleece: Excellent
Synthetic: Varies, but can be excellent
Down: Good

Midlayers (breathability)
Backcountry skiing in the Patagonia Nano-Air

Weight and Compressibility
For the backcountry explorer that needs to throw a warm layer in their pack to stay comfortable at mealtimes, the down jacket remains the best choice. An 800 fill-power down jacket with a thin shell is capable of compressing down to the size of a grapefruit (although over-compressing for long periods can damage the feathers, so don’t go too crazy). Synthetics vary quite a bit in compressibility. A lighter weight option like the Outdoor Research Ascendant is quite compressible, but even these thinner jackets don’t stuff down as compactly as down. Fleece jackets aren’t really all that compressible, and stuffing a mid or heavyweight fleece into a pack can make for a challenging endeavor.

Down: Excellent
Synthetic: Good
Fleece: Not good

Down Jacket stuffed size
The Arc'teryx Cerium LT down jacket packs down small

This can be a challenging category to judge because there is a wide range in levels of durability. Insulated synthetic and down jackets vary from super thin ultralight shells that are vulnerable to tears to tough jackets that you can throw on and forget about. The durability of a fleece on the other hand is usually quite good. It’s possible to put a hole in a fleece by catching it on a sharp object or just wearing it thin, but those are relatively uncommon occurrences or take place over a long period of time.

The near constant friction between your midlayer and outer shell jacket can cause abrasions and potential tears should a zipper catch the outer shell of your midlayer. In our opinion, because a couple extra ounces of weight are rarely a cause for concern while resort skiing, it’s worth it to get a more durable jacket. For insulated jackets, this means a tear-resistant fabric that is 20-denier (denier is a measurement of fabric thickness) or more. A jacket like the Patagonia Down Sweater has been popular for years on the slopes for having a great combination of sufficient toughness and minimal bulk.

Fleece: Very good
Down and Synthetic: Varies, but can be good

Getting a Proper Fit

Fit plays a very large role in an effective midlayer. Too much extra fabric and you will have bunching and general discomfort underneath your shell, and a jacket that’s too trim will restrict your mobility. It’s best to find that middle ground where you have complete freedom of movement—without the jacket riding up—and no excess bulk. We prefer a jacket that has a non-boxy cut that allows us to wear a similarly athletic-fitting outerlayer over the top. Arc'teryx in particular seems to consistently make jackets with this type of fit. As you're trying on midlayers, be aware of the normal pinch areas: around the waist, in the shoulders, and under the arm pits.

Midlayers (fit)
Black Diamond's First Light has an athletic cut that layers easily under a shell

Midlayer Jacket Features

It’s true that most folks don’t use the pockets of their insulating layers on the slopes all that often—it’s a pain to have to unzip a couple layers. However, midlayers are a classic choice for daily use, so don’t dismiss pockets completely. And if you’re eying a very technical piece that goes without pockets and you plan to use it around town, you may want to reconsider. Case in point: a more all-around choice may be the Patagonia R2 jacket as opposed to the dedicated lightweight R1 Pullover.

The North Face Ventrix (hand pockets)
Hand pockets are usually a helpful feature even if you'll mostly use the jacket as a midlayer

Performance midlayers occasionally will have thumbholes built into the sleeves. While serving as an opening for cold air to sneak in when not in use, the openings work well for keeping the sleeves in place during high effort activities or when taking on and off layers. User tip: if you’re eyeing a jacket that has this feature, we recommend checking to make sure the fabric around the thumbhole has some stretch so it doesn’t feel like yours thumb are being yanked around anytime you extend your arms.

For nearly all skiing conditions, a midlayer is best in non-hoody form. We always recommend using a helmet for skiing, so there is little reason to layer an insulated hood over top of that (not to mention most midlayer hoods are not helmet compatible). And for extra warmth under the helmet, a beanie is a far better choice. A hood also is prone to bunching up behind your neck and getting in the way of your outer layer; granted, some of the lower profile options aren’t as obtrusive. Overall, unless you really want a hood for around town use or will be wearing it quite a bit as an outer layer, we recommend steering clear for your skiing midlayer.

Don’t Forget Your Baselayer

If you’re like most folks, you spend a lot of time picking out the perfect shell, then move to your insulating options, and finally just grab a baselayer willy-nilly. Trust us, this is a poor methodology. As the layer that’s next-to-skin, a baselayer is at the core of moisture wicking, temperature regulation, and a number of other essentials. If you have a crummy baselayer, all the fancy tech in your mid and outer layers will be nearly worthless. Top materials include merino wool for its excellent temperature regulation and odor prevention, and synthetics are quite good at drawing moisture away from your skin. Check out our top baselayer picks to see which ones stand out as best.
Back to Our Top Midlayer Picks  Back to Our Midlayer Comparison Table

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