In the typical three-layer 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 and moderately warm mess? Then a lightweight fleece or synthetic jacket might do the trick. All three types have their proper applications, and below we break down the top midlayer designs of 2020. For more information, including the pros and cons of each form of insulation, see our midlayer comparison table and buying advice below the picks.

Best Overall Midlayer

1. Patagonia Nano-Air ($249)

Patagonia Nano-Air jacketInsulation: Synthetic
Weight: 11.2 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 puffy (minus the down) and your favorite sweatshirt. The result is a jacket that can be worn as a midlayer for winter sports or as an outer layer during the shoulder season 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. And while previous versions of the jacket haven’t aged remarkably well (the face fabric has been prone to staining and piling), we’ve been impressed so far with the latest update, which features a more durable shell (bonus: it’s made out of 87-percent-recycled materials).

The Nano-Air can be your Swiss Army Knife layering piece, but keep in mind that its 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 although the latest version stuffs into its chest pocket, the Nano-Air is far from the most packable option here. But Patagonia did shave over an ounce of weight—bringing it down to a very competitive 11.2 ounces—thanks to less stitching and elastic replacing the drawcord hem. All in all, 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 Hybrid... Read in-depth review
See the Men's Patagonia Nano-Air  See the Women's Patagonia Nano-Air


A Close Second (With More Weather Resistance)

2. Arc’teryx Atom LT ($239)

Arc'teryx Atom LT Jacket midlayerInsulation: Synthetic
Weight: 11.1 oz.
What we like: Great mix of mobility, warmth, and comfort.
What we don’t: Not 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 (although its stretchy fleece side panels 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 outer layer. 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


Best Budget Midlayer 

3. Columbia Steens Mountain 2.0 ($35)

Columbia Steens Mountain FleeceInsulation: Fleece
Weight: 16.6 oz.
What we like: Inexpensive and comfortable.
What we don’t: Limited warmth and questionable durability.

Sure, you can spend $300 or more on a midlayer and get some of the fluffiest down or techiest synthetic insulation on the market, but that doesn’t mean you have to. For days at the resort that aren’t super cold, you often can get away with a simple fleece like the tried-and-true Columbia Steens Mountain 2.0. Soft, inexpensive, and offered in a ton of sizes and colors, this is a very popular budget option. For $35 (and less on sale, which it frequently is), you get a no-frills midlayer with a surprisingly comfortable fit.

What are the shortcomings of going so cheap? The materials on the Steens Mountain 2.0 are very basic and the jacket has few features to speak of. It also won’t last as long as the higher-end fleece options on this list—the material is pretty soft and prone to pilling. Finally, the Steens is decently cozy but falls somewhere in the light to midweight category, meaning that the warmth it provides will be limited. For long and cold days at the resort, you’ll certainly want to go with a pricier down or synthetic midlayer. But for mild conditions and spring skiing with a baselayer underneath, the Steens Mountain 2.0 should get the job done.
See the Men's Columbia Steens Mountain 2.0  See the Women's Columbia Benton Springs


Best Down Midlayer

4. Patagonia Down Sweater ($229)

Patagonia Down SweaterInsulation: Down
Weight: 13.1 oz.
What we like: Warm, versatile, and well-built. 
What we don’t: Fit is a bit boxy. 

Few jackets have stood the test of time like the Patagonia Down Sweater. First and foremost, down offers the best warmth-to-weight ratio of any type of insulation. This jacket doesn’t breathe as well as the synthetic options on this list, nor will it insulate as well when wet (down has a tendency to clump up and lose much of its warmth when damp). But for use as a midlayer in cold and dry weather with a shell over top, we love what the Down Sweater has to offer. You get premium 800-fill down for warmth, a high-end build that should last for many seasons of skiing and casual use, and classic styling that looks good just about anywhere. It’s quite likely that you’ll wear the Down Sweater under your ski jacket during the day and around town at night. 

As mentioned above, this jacket is inherently less breathable than synthetic jackets, meaning that it’s great for the resort but not a viable option for backcountry skiing. We also don’t love the fit of the Down Sweater, which is boxier than we would prefer to accommodate a wide variety of people and uses. But it’s hard to knock the versatility: this jacket makes a terrific midlayer, packs down decently small for travel and hiking, and looks the part. For less coverage and a lower price point, see the Patagonia Down Sweater Vest below... Read in-depth review
See the Men's Patagonia Down Sweater  See the Women's Patagonia Down Sweater


Best of the Rest

5. The North Face Ventrix ($199)

The North Face Ventrix synthetic midlayer jacketInsulation: Synthetic
Weight: 12.7 oz.
What we like: A true Nano-Air competitor for $50 less.
What we don’t: Can’t match the Nano-Air in weight or coziness.

With the latest Ventrix, The North Face has taken direct aim at Patagonia’s popular Nano-Air above. The two jackets share a laundry list of similarities, including stretchy 60-gram synthetic insulations, lightweight and breathable shell and lining fabrics, three-pocket layouts, and slim fits. Performance-wise, the two midlayers also are quite close, offering enough warmth on most shoulder-season days while breathing reasonably well for activities ranging from cool-weather hiking to ski touring and snowshoeing in frigid temps. But where the Ventrix stands out is cost: at $199 for the non-hooded jacket, it undercuts the Nano-Air by a substantial $50.

With such a big price advantage, why do we prefer the Nano-Air? Simply put, Patagonia managed to nail all the little details while The North Face comes up a bit short. The Nano-Air has a cozier lining, provides just as much warmth yet weighs over an ounce less, and has a better DWR (we found the Ventrix’s shell soaked up light moisture rather quickly). In addition, the minimalist center zipper pull on the Ventrix consistently annoyed us as its two-string design comes undone too easily. It’s true that these are minor nitpicks and we love the overall feel, fit, and price savings of the Ventrix, but the downsides are enough to prevent it from unseating the Nano-Air... Read in-depth review
See the Men's The North Face Ventrix  See the Women's The North Face Ventrix


6. Arc’teryx Cerium LT ($349)

Arc'teryx Cerium LT jacket (2018-2019)Insulation: Down and synthetic
Weight: 9.9 oz.
What we like: Premium build and super warm for the weight.
What we don’t: Pricey and won’t breathe as well as the synthetic jackets above.

The Patagonia Down Sweater above is a great crossover piece, but the Cerium LT offers a step up in performance. Weighing in at just 9.9 ounces—one of the lightest midlayers on this list—the Cerium is warmer than the synthetic options and packs down smaller than the Patagonia with its 850-fill power and thinner shell. And despite using mostly down fill, Arc’teryx made this jacket capable in wet conditions by mixing in synthetic insulation in areas most prone to moisture: the collar, shoulders, underarms, and cuffs.

Why is the Arc’teryx Cerium LT ranked here? At $349 for the non-hooded version, it’s expensive and overkill for use strictly as a midlayer. The Down Sweater offers comparable warmth, and the packability and added features won’t come into play for most resort skiers. Having said that, the Cerium LT is a superb down jacket that can be used for everything from skiing and backpacking to casual use (Arc’teryx looks darn good in the city too). An added bonus: we like the fit of this jacket, with is noticeably less boxy and more performance-oriented than the Patagonia. For an even lighter down midlayer, see the Cerium SL... Read in-depth review
See the Men's Arc'teryx Cerium LT  See the Women's Arc'teryx Cerium LT


7. REI Co-op 650 Down Jacket 2.0 ($100)

REI 650 Down JacketInsulation: Down
Weight: 11 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 what REI Co-op has to offer. Their original 650 Down Jacket was an undeniable value, and the updated “2.0” is even more impressive. Most notably, this year’s version features soft-touch recycled nylon and reworked boxed baffling that gives it a distinctive look. While the 650 Down is a relatively simple jacket overall that lacks the fit and finish and just-right cut of a Patagonia or Arc’teryx product, it’s impossible to ignore the fantastic price of $100. In the end, the REI Down Jacket can go head-to-head in warmth and versatility with down sweaters that are double the cost from brands like Columbia and Marmot.

Keep in mind that this jacket 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’s 850-fill above, and its non-ripstop nylon is more vulnerable to tears. 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 650 Down Jacket 2.0  See the Women's REI 650 Down Jacket 2.0


8. Patagonia R2 Fleece ($169)

Patagonia R2 Fleece JacketInsulation: Fleece
Weight: 13.4 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 multiple models of varying insulation and weather-protectiveness 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) does not block wind or guard against light precipitation, which limits its utility as an outer layer. For more weather protection in a relatively similar jacket, check out the R2 TechFace (also $169), which features a more robust face fabric with a durable water repellant finish.
See the Men's Patagonia R2 Fleece  See the Women's Patagonia R2 Fleece


9. Outdoor Research Ascendant Hoody ($249)

Outdoor Reserach Ascendant HoodyInsulation: Synthetic
Weight: 13 oz.
What we like: Light, breathable, and a great value.
What we don’t: Hand pockets don’t have zipper closures; only available in a hooded version.

Like the Nano-Air, Atom LT, and Ventrix jackets above, the Outdoor Ascendant combines comfort, warmth, and temperature regulation with a small dose of weather protection for a midlayer that easily doubles as an outer layer. Overall, its performance is on par with the competition, with one major design difference: Outdoor Research removed the inner liner on the Ascendant, which both exposes the cozy Polartec Alpha Direct to the skin and keeps weight low. At a feathery 13 ounces for the hooded version and priced competitively at $249, we love what this jacket has to offer.

Where could the Ascendant be improved? We value the focus on cutting weight, but think that Outdoor Research took it one step too far by making the hand pockets without zippered closures (the chest pocket is zippered, however). Second, the Ascendant no longer comes in a non-hooded version, which we prefer for many midlayer uses. Finally, while cozy and lightweight, the exposed insulation on the interior is vulnerable to wear over time. But despite these pitfalls, we think the Ascendant is an affordable and thoughtful addition to the active insulation field... Read in-depth review
See the Men's Outdoor Research Ascendant  See the Women's Outdoor Research Ascendant


10. The North Face ThermoBall Eco ($199)

The North Face ThermoBall Eco jacketInsulation: Synthetic
Weight: 15.2 oz.
What we like: Good imitation of a lightweight down jacket.
What we don’t: Heavy and lacks the mobility of our top picks.

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.

In updating the jacket to the “Eco” this past fall, The North Face replaced the standard nylon shell and polyester fill with 100-percent-recycled materials. Unfortunately, the jacket is still on the heavy end of the spectrum, which makes it uncompetitive in weight with similar synthetic midlayers, including Arc’teryx’s Atom LT or Patagonia’s Nano-Air above. And like many products from The North Face, one of our main sticking points with the ThermoBall is fit (the Ventrix above is one exception). Although the latest model is more form-fitting than previous versions, we’ve found that overall the jacket runs boxy (it’s also a little big in the arms). While this is fine for everyday wear and use as a layering piece at the resort, we prefer a performance cut and some stretch for better mobility... Read in-depth review
See the Men's The North Face ThermoBall  See the Women's The North Face ThermoBall


11. Arc’teryx Atom SL Hoody ($229)

Arc'teryx Atom SL Hoody midlayerInsulation: Synthetic
Weight: 9.2 oz.
What we like: Breathable; extremely lightweight and packable.
What we don’t: No insulation in arms and hood; not as warm as the competition.

Not everyone needs to be counting ounces, but for backcountry missions, weight savings is paramount. With 40-gram, breathable Coreloft Compact insulation placed only in the core, the Atom SL (“superlight”) stands out as one of the lightest and most packable jackets on our list. You don’t get the same amount of warmth as with other synthetic midlayers, but you do get a highly breathable design that will keep you comfortable as you move down the trail or skin track. In addition, the SL’s low-profile hood stows easily behind your neck and doesn’t get in the way while touring.

The Atom SL is a true niche piece—keep in mind that both the arms and hood of the jacket are uninsulated, making it more akin to a vest in terms of warmth (but with the bonus of weather resistance if you choose to wear it without a shell). Unless you run very warm during activity, we don’t recommend it for true winter temperatures. Further, if you’re willing to compromise on breathability, a layer like the Cerium LT will provide a lot more warmth and loft for a small .7-ounce weight penalty. But for a lightweight insulator that’s ideal for mild-weather use or high-output activities, the Atom SL deserves a look... Read in-depth review
See the Men's Arc'teryx Atom SL  See the Women's Arc'teryx Atom SL


12. Black Diamond Wool Aspect Hoody ($249)

Black Diamond Wool Aspect HoodyInsulation: Wool/synthetic
Weight: 14.9 oz.
What we like: All the benefits of wool in a high-performance jacket.
What we don’t: More technical features than you need for standard midlayer use.

Black Diamond is relatively new to the apparel scene, but their Wool Aspect Hoody caught our eye as a thoughtful and practical piece. While wool is an incredible insulator—warm (even when wet), breathable, and fairly packable—it’s a rare event to see it used in such a performance-oriented jacket. But we think the Aspect Hoody pulls it off quite well, combining the wool with a synthetic fiber for durability and washability, and adding stretchy side panels for great freedom of movement. Tack on a helmet-compatible hood and a mesh pocket that doubles as a stuff sack, and the Aspect has all the bells and whistles that we love in a climbing or backcountry skiing-oriented midlayer.

We’ve tested a number of Black Diamond jackets at this point, and find that their level of quality and durability consistently falls mid-pack. You don’t get the fit and finish of a jacket like the Patagonia Nano-Air, but you’re also paying significantly less (the hooded Aspect comes in at $249, compared to the Nano-Air Hoody at $299). Overall, while the Aspect Hoody isn’t our top pick for a standard midlayer—it would be out-of-place at the resort—we think performance-oriented athletes will love its technical features and hood.
See the Men's Black Diamond Wool Aspect  See the Women's Black Diamond Wool Aspect


13. Patagonia Down Sweater Vest ($179)

Patagonia Down Sweater Vest (2018-2019)Insulation: Down
Weight: 9.8 oz.
What we like: Warmth where you need it most.
What we don’t: Less versatile as an outer layer.

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 outer layer 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


14. Mountain Hardwear Ghost Whisperer/2 ($300)

Mountain Hardwear Ghost Whisperer 2Insulation: Down
Weight: 8.3 oz.
What we like: Great warmth-to-weight ratio; premium materials and great fit and finish.
What we don’t: Not as warm as the competition; thin shell lacks durability.

For years now we’ve turned to the down-filled Ghost Whisperer as our favorite ultralight insulator for missions when weight and space are at a premium. At only 8.3 ounces, it’s the lightest jacket on our list, and touts a significantly smaller packed size than the competition. Plus, you get the longevity of down (which stands the test of time better than synthetic insulation) and—updated for this winter—a slightly more durable shell made of 100-percent-recycled materials. In terms of warmth-to-weight ratio and ultralight performance, it doesn’t get much more premium than the Ghost Whisperer.

But pitting the Ghost Whisperer up against other down midlayers on our list is not necessarily comparing apples to apples. The Mountain Hardwear is stuffed with only 2.65 ounces of 800-fill down, compared to the much warmer Arc’teryx Cerium LT (3.14 oz. of 850-fill down and synthetic Coreloft) and Patagonia Down Sweater (3.4 oz. of 800-fill down) above. And while durability is less of a concern with a midlayer, the Patagonia Down Sweater’s 20x30-denier shell makes it much more of a versatile piece than the ultra-thin Ghost Whisperer (10D x 10D). Mountain Hardwear’s revered ultralight insulator certainly has its time and place, but its lack of durability and high price point mean we recommend it only for the most discerning adventurers... Read in-depth review
See the Men's MH Ghost Whisperer/2  See the Women's MH Ghost Whisperer/2


15. Rab Paradox Light Pull-On ($150)

Rab Paradox Light Pull On midlayerInsulation: Synthetic
Weight: 9.1 oz.
What we like: Lightweight pullover design; versatile as a midlayer or outer layer.
What we don’t: Doesn’t stuff into its pocket for easy harness carry.

Rab’s Paradox Light Pull-On takes a spin on the basic synthetic jacket, combining the benefits of a warm, breathable layer with a streamlined pullover design that won’t weigh you down. And it’s versatile too: the Pull-On’s trim build is great for wearing under a shell, but its durable face fabric, elasticized cuffs, and a drawcord hem give it versatility as an outer layer on warm shoulder-season days. Plus, a brushed mesh interior and quick-drying shell mean you get moisture protection from both sides, whether you’re sweating up the skin track or stuck in a drizzle midway through a multi-pitch climb.

Given the Paradox Light’s minimalist design and climbing focus, we’re surprised to find that it doesn’t pack into its own pocket for easy carry on a harness. And while 9.1 ounces is light for a midlayer, the down-filled Mountain Hardwear Ghost Whisperer above offers more warmth and packability—plus the convenience of a full-length zipper—for almost a full ounce less. But for alpine conditions or truly high-output endeavors, we’ll always opt for the wet-weather assurance and breathability of a synthetic midlayer. For climbers, skiers, and other backcountry enthusiasts looking to streamline their kit, the Paradox Light is a great option.
See the Men's Rab Paradox Light Pull-On  See the Women's Rab Paradox Light Jacket


16. Arc’teryx Kyanite Hoody ($179)

Arc'teryx Kyanite HoodyInsulation: Fleece
Weight: 15 oz.
What we like: Great range of motion. 
What we don’t: A bit heavy and not as warm as a synthetic jacket.

For a serious performance fleece, we again turn to Arc’teryx and the versatile Kyanite. This jacket pretty much does it all: the midweight Polartec build works well as an active midlayer for backcountry skiing, yet it’s thick enough to wear as a standalone piece on the uphill and for climbing use in the shoulder seasons. We also appreciate the stretch of the fabric, which offers solid range of motion, and the trim fit means that you won’t have much in the way of bunching under a shell. 

What are the shortcomings of the Arc’teryx Kyanite? In general, fleece jackets are less warm and packable than comparable synthetic options, although you do save a bit in terms of cost. And at 15 ounces, the Kyanite is one of the heavier midlayers on the list, despite only providing moderate insulation. For a thinner fleece from Arc’teryx, the Konseal is a nice midlayer option for mild conditions and use as a cool-weather outer layer. 
See the Men's Arc'teryx Kyanite Hoody  See the Women's Arc'teryx Kyanite Hoody


17. 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 overtop for 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 clocks in at a “hefty” 4.8 ounces.
See the Men's Montbell Plasma 1000  See the Women's Montbell Plasma 1000


18. Smartwool SmartLoft 120 ($200)

Smartwool Smartloft 120Insulation: Synthetic (wool blend)
Weight: 15.6 oz.
What we like: Functional wool insulation and athletic fit.
What we don’t: Pricey; wool insulation isn’t all that warm.

Similar to the vest options above, the Smartwool SmartLoft 120 gives you warmth where you need it and range of movement where you don’t. All in all, we really like what Smartwool has done with this design, which includes a soft merino wool liner, SmartLoft 120g recycled wool insulation around the core, and a nylon exterior. Throw in a DWR finish and the result is an active midlayer, outer layer, or even baselayer that is comfortable, agile, and regulates your body heat quite well.

If you’re the type that runs cold, the SmartLoft 120 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 (not to mention it’s only on the front of the jacket). But we still appreciate the design, which is very functional and creative compared to traditional jackets that are uniform in materials and thickness throughout. And we love the versatility: you can ski, hike, bike, and even hit the town in this jacket. For a warmer and more performance-oriented wool option, check out the Black Diamond Wool Aspect Hoody above.
See the Men's Smartwool SmartLoft 120  See the Women's Smartwool SmartLoft 150


19. Mountain Hardwear Monkey Fleece ($175)

Mountain Hardwear Monkey Man 2 midlayerInsulation: Fleece
Weight: 13.4 oz.
What we like: Fuzzy and comfortable, yet very functional.  
What we don’t: Polarizing looks.

The Monkey 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 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.

While the updated Monkey features a solid fleece rather than the previous open weave construction, we do find that the jacket is still on the thin side. Further, the air-permeable material offers little wind and no water protection. Whereas some midlayers easily pull doubly duty as weather-resistant outer layers (the Arc’teryx Atom LT or Patagonia R2 TechFace, for example), you’ll almost always want to pair the Monkey Man with the added insurance of a shell. And although for the weight we’d prefer a bit more warmth (synthetic and down options are warmer), in terms of coziness, the Monkey Fleece cannot be beat.
See the Men's MH Monkey Fleece See the Women's MH Monkey Fleece


Midlayer Comparison Table

Jacket Price Type Insulation Weight Packable
Patagonia Nano-Air $249 Synthetic 60g FullRange 11.2 oz. Yes
Arc’teryx Atom LT $239 Synthetic 60g Coreloft 11.1 oz. Yes
Columbia Steens Mountain 2.0 $35 Fleece MTR filament fleece 16.6 oz. No
Patagonia Down Sweater $229 Down 800-fill down 13.1 oz. Yes
The North Face Ventrix $199 Synthetic 60g Ventrix 12.7 oz. No
Arc’teryx Cerium LT $349 Down/Synthetic 850-fill down; Coreloft 9.9 oz. Yes
REI Co-op 650 Down Jacket 2.0 $100 Down 650-fill down 11 oz. Yes
Patagonia R2 Fleece $169 Fleece Polartec Thermal Pro 13.4 oz. No
Outdoor Research Ascendant $249 Synthetic 95g Polartec Alpha 13 oz. No
The North Face ThermoBall Eco $199 Synthetic ThermoBall Eco 15.2 oz. Yes
Arc'teryx Atom SL Hoody $229 Synthetic 40g Coreloft Compact 9.2 oz. Yes
Black Diamond Wool Aspect $249 Wool/Synthetic 60g Lavalon 14.9 oz. Yes
Patagonia Down Sweater Vest $179 Down 800-fill down 9.8 oz. Yes
MTN Hardwear Ghost Whisperer/2 $300 Down 800-fill down 8.3 oz. Yes
Rab Paradox Light Pull-On $150 Synthetic Synthetic 9.1 oz. No
Arc'teryx Kyanite Hoody $179 Fleece Polartec Power Stretch Pro 15 oz. No
Montbell Plasma 1000 Vest $229 Down 1,000-fill down 3.1 oz. Yes
Smartwool SmartLoft 120 Jacket $200 Synthetic/Wool SmartLoft (wool/polyester) 15.6 oz. No
Mountain Hardwear Monkey Fleece $175 Fleece Polartec High Loft 13.4 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 their 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.

As far as warmth is concerned, 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 for a standard fleece jacket, including the Mountain Hardwear Monkey Fleece 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.

Best midlayers (Patagonia R2 Fleece)
Patagonia's R2 uses a combination of lightweight and midweight fleece fabrics

Synthetic Insulation
Opting for a synthetic jacket will most often involve a slight step up in 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. PrimaLoft was the first big name in synthetic insulation, but in recent years we’ve seen a variety of new blends come to market with a range of intentions. The North Face’s Thermoball and Patagonia’s PlumaFill, for example, seek to mimic the weight and compressibility of down, while other insulations prioritize breathability (like the impressive FullRange insulation used in Patagonia’s Nano-Air jacket). Depending on your needs, there’s likely a synthetically insulated jacket ideal for the job, and we particularly like highly breathable options 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 (logo close-up)
Our top-rated Patagonia Nano-Air uses 60-gram synthetic fill

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 found in areas 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 of 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

Many of our favorite baselayers are made with merino wool, due to its comfort, warmth, and ability to resist odor better than synthetic materials. And while this natural alternative isn’t seen as often in midlayers, it can go head-to-head with synthetics in terms of warmth (even when wet) and temperature regulation. But this all-natural insulator does have its downsides: wool can be more of a hassle when it comes time to do the laundry, and it lacks the warmth-to-weight ratio of down. As a result, we most often see it mixed in with a hybrid insulation design, like the wool/polyester blends seen in the Black Diamond Wool Aspect Hoody and Smartwool SmartLoft 120.

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.

Midlayers (fleece)
Fleece jackets fall at the bottom of the warmth scale 

Another natural insulator, wool offers cozy warmth and comes with the benefit of resisting odors better than other materials. However, wool’s warmth-to-weight ratio is less impressive, and it’s often on the expensive end of the spectrum. 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 (some designs like the Patagonia Micro Puff are getting close), synthetic jackets are still a great choice for skiing in typical resort conditions.

A fleece jacket may be at the bottom of our warmth list, but that'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
Wool: Very good
Synthetic: Very Good
Fleece: Good

The North Face Ventrix (at camp)
The North Face's Ventrix offers moderate warmth

Snow and Wet-Weather Protection
This category is where the down jacket struggles in relation to the other three. 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 synthetic, fleece, or wool insulation is the fact that they are still able to retain some insulating properties when wet (as a downside, wool can grow very heavy when saturated). Fleece is top of the class in terms of warmth when wet (due in part to the naturally hydrophobic nature of the polyester construction) and can also dry faster than synthetic fibers. However, many synthetic jackets will add a DWR coating to their shell to bead water, making them a far more suitable outer layer option than fleece. 

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

Midlayers (Outdoor Research Ascendant)
Outdoor Research's synthetic Ascendant is wind- and water-resistant 

Breathability is another strong suit of fleece, synthetic, and wool 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. Wool comes in a close second—this natural insulator excels at temperature regulation and, as a bonus, minimizes odor retention. Products like Patagonia’s Nano-Air are pushing synthetic jackets well into the high-performance world, but it can be hit or miss (and these jackets have a knack of holding stink). 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 (and working up a sweat can lead to the insulation getting wet and losing its ability to keep you warm).

Fleece: Excellent
Wool: 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 and wools (often wool/synthetic blends) vary quite a bit in compressibility. Lighter-weight options like the Outdoor Research Ascendant or Smartwool SmartLoft are reasonably compressible, but even these thinner jackets don’t stuff down as compactly as down fill. Fleece jackets aren’t really all that compressible, and throwing a mid or heavyweight fleece into a pack can make for a challenging endeavor.

Down: Excellent
Synthetic: Varies, but can be very good
Wool: Varies, but can be good
Fleece: Not good

Midlayers (Cerium LT stuff sack)
The Arc'teryx Cerium LT down jacket packs to a small size

This can be a challenging category to judge because there is a wide range in levels of durability. Insulated synthetic, down, and wool jackets vary from super-thin ultralight shells that are vulnerable to tears to tough jackets that you can throw on and forget about. In terms of the insulation itself, down and wool have long lifespans (and will continue to provide warmth as long as the shell of the jacket is intact), whereas synthetic materials tend to pack out over time. 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, Synthetic, & Wool: Varies, but can be good

Midlayers (Columbia Steens Mountain)
Fleece midlayers are generally quite durable

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 outer layer 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 (Arc'teryx Atom SL jacket layering)
Size your midlayer so you can layer a jacket overtop

Hood vs. No Hood

Deciding whether or not to opt for the hooded or non-hooded version of a midlayer might seem like a relatively inconsequential decision, but it’s actually deserving of some thought. For the most part, we prefer a non-hooded midlayer, particularly when we know we’ll be layering it under a shell. A hood is prone to bunching up behind the neck under an outer layer, and it can be cumbersome to don both midlayer and shell hoods at the same time. Further, if you’re like us and participate in activities where you wear a helmet (skiing, climbing, biking, etc.), keep in mind that most midlayer hoods are not helmet compatible.

But there are a few scenarios where we love a hooded midlayer. For one, if we are wearing a helmet, a svelte hood worn underneath can provide a good deal of warmth for both the head and neck, and will prevent snow from entering the jacket at the collar. Second, if we think we’ll be wearing our midlayer as an outer layer (which we often do with jackets like the Arc’teryx Atom LT or Outdoor Research Ascendent), we love the extra warmth and protection of a hood. In the end, the decision of hood vs. no hood will come down to one of personal preference, and it’s important to know how you’ll be using your midlayer when considering your needs.

Midlayers (hardshell and hood)
When paired with a shell, the hood of a midlayer can get in the way 

Midlayer Jacket Features

Midlayers are fairly simple pieces, especially considering they’re meant to hide under your weatherproof outer layer. Feature sets are often limited to pockets, thumbholes, and hoods (which we discussed above). It’s true that most folks don’t use the pockets of their insulating layers on the slopes or in the backcountry 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 (which features three total pockets) as opposed to the dedicated lightweight (and pocket-less) Rab Paradox Lite.

REI Co-op 650 Down Jacket (hand pockets)
Using the hand pockets on REI's 650 Down Jacket 2.0

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 your thumbs are being yanked around every time you extend your arms.

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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