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. Are temperatures mild or are you traveling at a breakneck pace? 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 midlayers of the 2023-2024 season. 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: Arc’teryx Atom Jacket
- Best Budget Midlayer: Columbia Steens Mountain 2.0
- Most Ultralight and Packable Midlayer: Patagonia Micro Puff
- Best Breathable Midlayer: Patagonia R1 Air Full-Zip Hoody
- Best Down Midlayer: Arc’teryx Cerium Jacket
Best Overall Midlayer
Weight: 11.6 oz.
What we like: Great mix of mobility, warmth, and comfort.
What we don’t: Not as breathable as some synthetic and fleece options.
Arc’teryx has built its reputation on legendary shells and insulated jackets, and one of its biggest sellers is the Atom Jacket (previously called the Atom LT). Simply put, this is a top-notch midlayer that nails the essentials. You get an excellent balance of breathability and warmth, great mobility, and a just-right cut (updated in the most recent version) that fits most folks really well. The 60-gram Coreloft Compact fill is time-tested and will keep you warm even when wet, and stretchy fleece side panels boost ventilation and freedom of movement. And unlike many midlayers here, the Atom also works great as a standalone jacket with a decently tough and weather-resistant shell.
With its synthetic insulation, supple face fabric, and stretchy side panels, the Atom offers significantly more breathability than down or down-mimicking designs like Arc’teryx’s own Cerium and Patagonia’s Micro Puff below. That said, if you run warm or participate in particularly high-output activities, fleece jackets like the Patagonia R1 Air and Norrøna Falketind Alpha120 below will be more adept at dumping heat. But Arc’teryx’s synthetic jacket is the most well rounded of the bunch, with winter-ready warmth and a design that effectively toes the line between casual and performance use. Whether you’re cruising laps at the ski resort, commuting in the city, or backpacking in the shoulder seasons, it gets the job done. Finally, it’s worth noting that Arc’teryx also makes the Atom in an even lighter (9.5 oz.) SL Hoody and warmer heavyweight design available with or without a hood... Read in-depth review
See the Men's Arc'teryx Atom Jacket See the Women's Arc'teryx Atom Jacket
Best Budget Midlayer
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 $65 (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 Ultralight and Packable Midlayer
Weight: 10.4 oz.
What we like: The light weight and packability of down in a synthetic jacket that insulates even when wet.
What we don’t: Not as comfortable or breathable as the Atom above.
Arc'teryx Atom above is our top choice for resort skiing and daily wear, but with bulky, sweatshirt-like fabric that doesn’t pack down super well, it’s far from a minimalist midlayer. Enter the Micro Puff, which combines an extremely thin (10D) face fabric with Patagonia’s light and lofty PlumaFull insulation for a super cozy jacket that stuffs into its left pocket and clocks in at 10.4 ounces. PlumaFill mimics down plumage, providing similar warmth, low weight, and packability of a down jacket in a design that still insulates when wet. The result is a high-performance midlayer ideal for weight-conscious pursuits like backcountry skiing and climbing.
Despite its technical prowess, it’s important to note that the Micro Puff is not for everyone. Unlike the Atom, it does not excel in the breathability department, nor do you get the stretchy and supple feel that makes many synthetic midlayers so easy to wear. If weight is not an issue—or if you plan to keep your jacket on all day—we’d stick with a midlayer more intended for active insulation, like the Atom or R1 Air below. But as the lightest synthetic jacket on our list, the Micro Puff is hard to beat when weight and space are top priorities... Read in-depth review
See the Men's Patagonia Micro Puff See the Women's Patagonia Micro Puff
Best Breathable Midlayer
Weight: 12.9 oz.
What we like: The ultimate athletic fleece.
What we don’t: Limited water resistance (no DWR treatment).
Lightweight performance fleeces are a growing trend, and we particularly like what Patagonia has done with their R1 Air. With an emphasis on breathable warmth in a lightweight build, this is an intriguing midlayer piece for high-output activities like backcountry skiing or climbing. Fleeces already tend to be a rather air-permeable breed (notably more so than down insulation), but the R1 Air ups the ante with hollow fiber yarns and a zig-zag patterning that work together to trap warmth and dump heat. The end result is a highly technical fleece that offers ample insulation for mild conditions but truly shines when you venture off-trail.
Along with their breathability, we also like fleeces as midlayers in terms of value. Patagonia apparel isn’t cheap, but at $179 the R1 Air is a nice step down in price from the synthetic and down offerings here. The major compromise is that this jacket (and fleece in general) does not block wind or guard against light precipitation, which limits its utility as an outer layer. To complicate matters, the R1 Air Full-Zip comes with a hood (not always ideal for midlayer use), but you can also step down to the non-hooded Zip-Neck or Crew versions for less bulk under a shell. But for big efforts on the skin track or the sharp end, breathability should be high on your priority list—and it’s here that the R1 Air truly delivers.
See the Men's Patagonia R1 Air Full-Zip See the Women's Patagonia R1 Air Full-Zip
Best Down Midlayer
Insulation: Down and synthetic
Weight: 10.6 oz.
What we like: Super warm for the weight and added wet-weather protection in a sustainably built package.
What we don’t: Pricey and won’t breathe as well as a synthetic jacket.
In most cases, we recommend synthetic-insulated or fleece jackets for midlayer use: They’re relatively breathable and provide warmth even when wet. But in dry conditions or for low-output activities like casual resort skiing, a down midlayer can be a really nice choice. Not only is down extremely lofty and cozy, but it’s also very lightweight and packable compared to the alternatives. Among the options, Arc’teryx’s Cerium Jacket (formerly the Cerium LT) is our top pick, thanks to its minimalist 10.6-ounce build, premium 850-fill down, and its trim, performance-oriented fit. We’re also big fans of the hybrid design, which features synthetic insulation in areas most prone to moisture (the collar, shoulders, underarms, and cuffs) for a bit of wet-weather assurance. Finally, Arc’teryx gave the Cerium a sizable sustainability boost with the recent update, including the use of recycled and bluesign-approved fabrics, bio-based materials, RDS-certified down, and a dope-dyed shell, which only add to the all-around appeal.
The Cerium Jacket is undeniably expensive at $380 for the non-hooded version (the past-generation Cerium LT was a little cheaper at $349), especially considering that for over $100 less, the synthetically insulated Atom is almost as warm, much more breathable and durable, and more protective in inclement weather. But for weight-conscious missions in dry areas (think backpacking in the desert) or if you just like the high-end feel of down, it doesn’t get much better than the Cerium. And it’s hard to beat Arc’teryx’s premium fit, which is noticeably less boxy than alternatives like the Down Sweater below and looks great for both backcountry and around-town use... Read in-depth review
See the Men's Arc'teryx Cerium Jacket See the Women's Arc'teryx Cerium Jacket
Best of the Rest
Insulation: Synthetic and fleece
Weight: 10.5 oz.
What we like: A high-performance combination of synthetic insulation and fleece.
What we don’t: Not as warm as most jackets here.
It’s no secret at this point that synthetic fill and fleece are our two favorite midlayer insulators—they’re breathable, sleek, and (unlike down) still provide warmth when damp. We’re usually forced to choose between one or the other, but Patagonia’s unique Nano-Air Light Hybrid offers the best of both worlds with an intelligent combination of lightweight synthetic fill (40g FullRange) at the front and cozy fleece (similar to that of the R1 Air above) at the back, sides, and underarms. Protecting the synthetic fill is a 100% recycled, soft yet durable, and impressively air-permeable face fabric, borrowed from Patagonia’s beloved Nano-Air Jacket. The net result is a high-performance midlayer (or great standalone piece), ideal for shoulder-season climbing, backpacking, ski touring, and more.
The Nano-Air Light Hybrid isn’t as insulative as most jackets here—the 40-gram FullRange is thinner than the more standard 60-gram fill, and the panels of fleece don’t do much to keep out the wind—but it’s a good example of less is more. This design is ideal for when jackets like the Atom or Cerium above are just too much (think mild shoulder-season conditions or high-output activities), and we’re big fans of the breathable back when adventuring with a backpack. Keep in mind that the Nano-Air Light Hybrid is designed to fit particularly snugly, although the sizing is ideal for midlayer use. And for a bit more jacket, check out the classic Nano-Air Hoody ($329), which features 60-gram FullRange insulation throughout.
See the Men's Patagonia Nano-Air Light Hybrid See the Women's Nano-Air Light Hybrid
Weight: 10.9 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 650 Down Jacket is reasonably light at 10.9 ounces, provides solid warmth with over 4 ounces of 650-fill-power down, and features a windproof and water-resistant shell. REI also honed the design with the latest version by adding a hem adjustment, a more durable ripstop nylon shell, and traditional horizontal baffles (the previous version had box baffles). The price did go up by $29, but the jacket still easily undercuts most competitors by $100 or more. For daily use, travel, light adventuring, and as a midlayer for resort skiing, you simply won’t find a better deal.
Budget-oriented products almost always come with compromises, and REI’s down jacket does fall short for serious performance use. The 650-fill down isn’t quite as warm or compressible as the 800-fill of the Cerium or Down Sweater above, and the most recent version no longer packs into its hand pocket (nor does it include a stuff sack). What’s more, the fit is fairly roomy, which is great for standalone use but less ideal for sliding under a trim-fitting hardshell. But circling back to value, the 650 Down Jacket’s combination of warmth, build quality, and price are simply unmatched, making it an easy “yes” for those on a budget. REI leads the outdoor industry in inclusive sizing, too: The men’s jacket comes in 10 sizes, including four “Tall” sizes, while the women’s version is available in eight sizes from XS to 3X.
See the Men's REI 650 Down Jacket See the Women's REI 650 Down Jacket
Weight: 9.9 oz.
What we like: Lighter and more packable than most fleeces but still quite warm.
What we don’t: Pricey; thin materials lack durability.
Norway-based Norrøna competes with leading mountain brands like Arc’teryx and Rab, and we’ve been extremely impressed by everything from their technical hardshells to their down jackets and midlayers. Their Falketind Alpha120 Zip Hood fleece here is no exception, combining premium materials and a performance-ready feature set in a thoughtfully built package. Touted as the brand’s most breathable and quick-drying midlayer, the Alpha120 features a mix of Polartec’s uber-light Alpha (120g) and Power Grid (139g) fleece fabrics—the former concentrated around the core for warmth and the latter offering stretch along the underarms, sides, and hood. Tack on integrated hand gaiters; harness- and hipbelt-friendly pockets; and a trim, body-hugging fit, and you have a high-quality and cozy technical piece for heart-pumping winter adventures.
The Falketind Alpha120 is decidedly thin—heck, you can even see through the Alpha insulation when you hold it up to the light—but we’ve found that it provides an impressive amount of warmth, even at camp or during trailside breaks. What’s more, it packs up smaller than most fleeces, and at just 9.9 ounces is a lot lighter than offerings like the Patagonia R1 Air (12.9 oz.) and Arc’teryx Kyanite (13.8 oz.). It’s true that the Power Grid fabric is more prone to pilling and staining than more robust fleece varieties, and the Alpha fabric is notably lacking in wind resistance. But as a lightweight insulator that’s trimmer-fitting and more breathable than down, the Falketind Alpha120 deserves a look.
See the Men's Norrøna Falketind Alpha 120 See the Women's Norrøna Falketind Alpha120
Weight: 12.1 oz.
What we like: The breathability of fleece but with a tough and weather-resistant shell.
What we don’t: Expensive and not particularly durable.
The midlayer category is a big one, encompassing everything from down and synthetic insulators to fleece jackets, hybrids, vests, and more. And then there’s the Arc’teryx Proton Lightweight, which defies categories with its unique and high-performance design. On the outside, the Proton Lightweight features a stretchy shell fabric that’s reminiscent of Patagonia’s Nano-Air material (but a bit thinner). The inside is where things get interesting, with Octa Loft insulation that looks a bit like fleece but with more heat-trapping and moisture-wicking fibers than most varieties. The result is a highly breathable yet tough and weather-resistant jacket that’s ideal for heart-pumping activities like ski touring and winter running.
At $260, the Proton Lightweight is undeniably expensive, and we do have durability concerns with the thin (20D) face fabric and exposed Octa Loft insulation. But by forgoing a liner, Arc’teryx boosts breathability by a noticeable margin. You’ll pay a lot more than you would for a fleece jacket like the Patagonia R1 Air above, but the Proton Lightweight performs similarly during active use and tacks on the added protection (and sleek look) of a shell. We know ski guides who wear this jacket daily during the winter months, which is true praise for a midlayer. It’s also worth taking a look at the standard Proton Hoody, which features a more traditional synthetic build but retains the focus on breathability.
See the Men's Arc'teryx Proton Lightweight See the Women's Arc'teryx Proton Lightweight
Weight: 10 oz.
What we like: Affordable; impressive warmth for the weight.
What we don’t: Not very breathable and shell fabric is fragile.
Outdoor Research has come out with a number of innovative synthetic jackets over the years, and the SuperStrand LT is their latest effort. Like the Micro Puff above, the SuperStrand LT aims to provide maximum warmth for minimal weight and bulk, and it delivers in spades. The jacket combines a super thin (12D) nylon ripstop shell with VerticalX’s new SuperStrand technology, a down-mimicking synthetic insulation that is impressively lofty, even when wet. And unlike many of the bulkier fleece and active insulation pieces here, it stuffs down into a corner of your pack when not in use (or into its left-hand pocket). Added up, the SuperStrand LT is an intriguing new midlayer for weight-conscious backcountry skiers, alpine climbers, and mountain runners alike.
We’ve learned to count on Seattle-based Outdoor Research for great performance at a low cost, and—true to form—the SuperStrand LT checks in at $80 less than the aforementioned Patagonia Micro Puff. That said, it's not quite as warm or durable as the Micro Puff, and OR consistently falls short of Patagonia in terms of quality of materials and fit and finish. Finally, there are a couple downsides to the SuperStrand’s purpose-built design: It doesn’t breathe as well as active midlayers like the Nano-Air Light Hybrid or R1 Air above, and the thin shell fabric is fragile and limits the jacket’s use as a standalone piece. But as an emergency layer or for added warmth at chilly belays, the OR is a great value (and it’s also available in a hooded version for $235)... Read in-depth review
See the Men's Outdoor Research SuperStrand LT See the Women's Outdoor Research SuperStrand LT
Weight: 13 oz.
What we like: Versatile, well built, and cozy warmth.
What we don’t: Not a weight and packability leader.
Few jackets have stood the test of time like the Patagonia Down Sweater. Iconic both for its classic styling and lofty warmth, the Down Sweater is a versatile down jacket that’s equally at home in town as it is on the slopes. With the most recent version, you get 5 ounces of premium 800-fill down (up from the previous model’s 3.4 oz.), a durable shell made from recycled fishing nets, and drop-in internal pockets for additional storage. Given that Patagonia’s high-end build should last many seasons of skiing and casual use, the Down Sweater is decently priced at $279 (a significant savings compared to the $380 Cerium Jacket above).
Unlike the Cerium Jacket, which uses synthetic insulation in high-exposure areas, the Down Sweater features 100% down. As a result, you’ll need to be especially careful to stay dry in wet conditions and should plan to pair it with a waterproof hardshell or ski jacket. The rest of the jacket follows suit with less of a performance focus overall—the fit is roomy enough to accommodate casual layers underneath (like a flannel), weight is a bit hefty at 13 ounces (compared to the Cerium’s 10.6 oz.), and the 800-fill down is slightly less premium than the Arc’teryx’s 850-fill (although you do get considerably more of it). But for a versatile midlayer for a wide variety of people and uses, the Down Sweater is well worth a look... Read in-depth review
See the Men's Patagonia Down Sweater See the Women's Patagonia Down Sweater
Weight: 13.8 oz.
What we like: Premium fleece fabric offers great comfort, range of motion, and breathability.
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 Jacket (previously called the Kyanite AR). 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 or for shoulder-season climbing. We also appreciate the stretch of the fabric, which offers solid range of motion, and the trim fit means 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 while the Kyanite features a durable nylon shell, it won’t hold up to much more than a light breeze or sprinkle. Finally, at 13.8 ounces, it’s one of the heavier midlayers on the list despite only providing moderate insulation. But for a wildly comfortable and premium fleece that’s one of our go-to jackets for both skiing and casual use, we’re big fans of the Kyanite. Arc’teryx also makes the Kyanite Lightweight (or Kyanite LT for women), which uses a lighter and stretchier fabric.
See the Men's Arc'teryx Kyanite Jacket See the Women's Arc'teryx Kyanite Jacket
Insulation: Synthetic and merino blend
Weight: 12.7 oz.
What we like: Snug fit is ideal for layering or as a standalone piece for climbing.
What we don’t: Not as versatile or lightweight as the Patagonia Nano-Air Light Hybrid.
Black Diamond specializes in performance-oriented outerwear for climbing and skiing, and their recently updated First Light collection is home to a few nice midlayer options. We’d equate the First Light Hybrid Hoody to a mullet—business at the front, party in the back: You get PrimaLoft Gold Active insulation and a stretch-nylon shell with a PFC-free DWR finish at the chest, hood, and arms; on the back and underarms, Black Diamond patterned a low-profile merino/polyester blend, which boosts breathability and freedom of movement and resists odors better than most synthetic materials. Tack on a helmet-compatible hood and chest pocket that converts to a stuff sack, and there’s no question that the First Light Hybrid is made for mountain adventures.
We tested a previous version of the First Light Hybrid and had a lot of praise for the design. Unlike many synthetic jackets, which can have fairly roomy dimensions, the BD really felt like a midlayer with its trim shape and snug-fitting yet stretchy back. As a result, it layered very well under a shell while skiing and also became one of our go-to jackets for cold-weather rock climbing. All told, the First Light Hybrid Hoody isn’t too dissimilar from the Nano-Air Light Hybrid above in terms of intentions, although it’s slightly bulkier and doesn’t cross over quite as well for casual use. But for $24 less than the hooded Patagonia, it's nevertheless a great alternative for those who like the warmth and odor resistance of merino wool.
See the Men's BD First Light Hybrid Hoody See the Women's BD First Light Hybrid Hoody
Weight: 11 oz.
What we like: Affordable; lightweight fleece panels add mobility and venting.
What we don’t: Only comes in a hooded version; not versatile as an outer layer.
In a landscape dominated by techy fabrics and ultralight insulation, fleeces are the true midlayer underdog. That said, performance fleeces have won us over in recent years, as evidenced by selections like the Patagonia R1 Air, Norrøna Falketind Alpha120, and Arc'teryx Kyanite above. This genre of fleece is far from the bulky, high-pile styles of yore: Modern, airy fabrics keep weight low and breathability high, and the trim-fitting designs fare well under technical shells. Joining our list of favorites is Rab’s performance-oriented Ascendor Hoody, arguably the most technical offering of the bunch. We especially love the Ascendor for rock climbers and backcountry skiers: Its snug fit and stretchy fabric offer great freedom of movement, and two fabric weights help provide a nice balance of temperature regulation and warmth.
The Ascendor Hoody features 235-weight grid-backed fleece, along with panels of lighter gridded fleece at the back, lower arms, and hood. This combination gives you midweight warmth along with increased mobility and venting, making it a suitable option for high-output days in cold conditions. We also appreciate the trim-fitting hood, which slides easily underneath a helmet. In terms of the competition, the Kyanite is slightly warmer and offers a bit more performance as an outer layer (thanks to its durable nylon shell), while the Patagonia R1 Air has more crossover appeal (but lacks the mobility of the Rab). Added up, the Ascendor is arguably the most purpose-built midlayer of the three, and it’s also the most affordable at just $145. For standalone performance, check out the Ascendor Summit Full Zip Hoody ($200), which tacks on windproof and water-resistant fabric in high-exposure areas.
See the Men's Rab Ascendor Hoody See the Women's Rab Ascendor Hoody
Weight: 8 oz.
What we like: Warmth where you need it most.
What we don’t: Less versatile as an outer layer.
For big efforts or mild conditions, there are a lot of reasons to opt for a vest over a jacket. Built to keep you warm in the core and minimize bulk and weight everywhere else, they’re a minimalist choice and promote air flow better than most jackets. Vests also keep your arms free and unencumbered, which is great news for climbers, cross-country skiers, and even daily wearers. Within this category, the Patagonia Nano Puff Vest is one of our favorite designs, clocking in at just 8 ounces with a lightweight shell (20D) and 60-gram PrimaLoft Gold Eco insulation.
The Nano Puff is Patagonia’s most affordable synthetic insulated vest at $179, but there are some benefits to opting for the vest version of the Nano-Air. For $20 more, it’s the better design for high-output uses like cross-country skiing and winter running, with more breathable construction and a soft, body-hugging feel. On the other hand, we do prefer the more durable shell of the Nano Puff for casual use, especially when worn as an outerlayer. And finally, keep in mind that Patagonia also offers a number of fleece vest options for considerably less, but these lack the weather protection and sleek look of the aforementioned synthetic designs.
See the Men's Patagonia Nano Puff Vest See the Women's Patagonia Nano Puff Vest
Weight: 10 oz.
What we like: A breathable and warm midlayer that won’t impede movement.
What we don’t: Expensive and doesn’t double as an outer layer.
For climbers and backcountry skiers, a fleece can be a really nice midlayer choice. Not only do they breathe well and dry quickly, but many performance varieties manage to pack a lot of warmth into a fairly minimal build. The Black Diamond Coefficient is one such jacket: With gridded Polartec Power Dry fabric, the fleece traps heat inside the waffle-like construction, keeping you warm during trailside breaks or belays but letting air move around when you’re on the go. And its trim fit slides easily under a hardshell or windbreaker jacket (including an under-the-helmet scuba hood), eliminating the bulk you sometimes get from an insulated design.
The Coefficient offers similar levels of warmth as the Patagonia R1 Air Hoody above. But where the Patagonia prioritizes breathability, the Black Diamond boosts protection and durability with its brushed fleece shell. To be sure, the Coefficient can't match the weather resistance of synthetic jackets like the Arc’teryx Atom or Proton, but it's a decent outer layer in clear conditions, similar to the Kyanite above (for 3.8 oz. lighter and with significantly less warmth). Black Diamond doesn’t quite match brands like Patagonia and Arc’teryx in terms of build quality, but the Coefficient is undeniably a comfy and high-performance fleece option. It’s also worth mentioning the Coefficient LT Hybrid—one of our favorite hybrid fleeces of late—which features a thin, baselayer-like material and tacks on an insulated front panel for additional warmth and weather resistance... Read in-depth review
See the Men's Black Diamond Coefficient See the Women's Black Diamond Coefficient
Insulation: Merino/polyester blend
Weight: 15.9 oz.
What we like: Functional wool insulation and athletic fit.
What we don’t: Pricey; wool insulation isn’t all that warm.
Similar to a vest, the Smartwool Smartloft gives you warmth where you need it without compromising range of motion. All in all, we really like what Smartwool has done with this design, which includes a soft merino wool liner and Smartloft 60-gram recycled wool insulation at the front, covered by a nylon shell. 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 who runs cold, the Smartloft 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 60-gram fill isn't all that warm for the weight (and 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. A final alternative to consider is Smartwool’s own Intraknit Merino Fleece Hoody, which offers a step up in breathability with mesh paneling under the arms and is similarly soft and comfortable (although more prone to snagging, we've found).
See the Men's Smartwool SmartLoft See the Women's Smartwool SmartLoft
|Arc’teryx Atom Jacket||$280||Synthetic||60g Coreloft Compact||11.6 oz.||Yes|
|Columbia Steens Mountain 2.0||$65||Fleece||Fleece||16.6 oz.||No|
|Patagonia Micro Puff||$279||Synthetic||65g PlumaFill||10.4 oz.||Yes|
|Patagonia R1 Air Full-Zip Hoody||$179||Fleece||Jacquard fleece||12.9 oz.||No|
|Arc’teryx Cerium Jacket||$380||Down/synthetic||850-fill down; Coreloft||10.6 oz.||Yes|
|Patagonia Nano-Air Light Hybrid||$249||Synthetic/fleece||40g FullRange; R1 Air fleece||10.5 oz.||No|
|REI Co-op 650 Down Jacket||$129||Down||650-fill down||10.9 oz.||No|
|Norrøna Falketind Alpha120||$219||Fleece||120 & 139g Polartec fleece||9.9 oz.||No|
|Arc'teryx Proton Lightweight||$260||Synthetic||Octa Loft knit||12.1 oz.||No|
|Outdoor Research SuperStrand LT||$199||Synthetic||VerticalX SuperStrand||10 oz.||Yes|
|Patagonia Down Sweater||$279||Down||800-fill down||13 oz.||Yes|
|Arc'teryx Kyanite Jacket||$180||Fleece||Polartec Power Stretch Pro||13.8 oz.||No|
|Black Diamond First Light Hybrid||$275||Synthetic/merino||PrimaLoft Gold Active; wool||12.7 oz.||Yes|
|Rab Ascendor Hoody||$145||Fleece||235g Thermic G fleece||11 oz.||No|
|Patagonia Nano Puff Vest||$189||Synthetic||60g PrimaLoft Gold Eco||8 oz.||Yes|
|Black Diamond Coefficient Hoody||$180||Fleece||Polartec Power Dry fleece||10 oz.||No|
|Smartwool SmartLoft||$210||Merino blend||60g wool/polyester||15.9 oz.||No|
- Midlayer Insulation Types
- Important Strengths and Weaknesses
- Fit and Sizing
- Hood vs. No Hood
- Don't Forget Your Baselayer
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 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 lightweight fleece—Patagonia's R1 Air and the Norrøna Falketind Alpha120, for example—is a thin and relatively packable option that breathes very well but isn’t as warm. These are great for mild-weather skiing or high-exertion activities like backcountry skiing and climbing. Midweight fleeces are the most popular style due to their versatile warmth, and include models like the Rab Ascendor and Arc'teryx Kyanite. These jackets are insulating enough for most cold days but don’t compromise much in the way of breathability. Finally, heavyweight fleeces are the bulkiest and warmest in their class, which limits their use to casual environments or truly cold days on the slopes.
Opting for a synthetic jacket will most often involve a slight step up in cost from a fleece but comes with reduced bulk and often a more weather resistant shell. And as an upgrade from down fill, synthetics are more breathable and 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. Outdoor Research's VerticalX SuperStrand 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 Light Hybrid 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.
Despite impressive innovation in synthetic materials, there’s still no match for the warmth, lightweight, and packability of natural goose or duck plumage. 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 Arc’teryx Cerium Jacket 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 to 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.
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 blends seen in the Black Diamond First Light Hybrid and Smartwool SmartLoft.
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.
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 and Outdoor Research SuperStrand LT 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.
Synthetic: Very good
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.
Synthetic: Very good
Down: Not good (even hydrophobic down falls short)
Breathability is another strong suit of fleece, synthetic, and wool insulation. Overall, we give the edge to fleeces, which are naturally porous, and newer models like the Patagonia R1 Air open up even more avenues for hot air to escape. Wool comes in a little behind—this natural insulator excels at temperature regulation and, as a bonus, minimizes odor retention (but it can soak up sweat and moisture). Synthetic jackets like Arc’teryx's Atom Jacket offer great breathability for active use, but the category as a whole can be hit and miss (we often overheat in the Patagonia Micro Puff, for example). Unfortunately, down jackets are on the outside looking in here. Their supreme warmth retention doesn’t breathe nearly as well as the other options (and working up a sweat can lead to the insulation getting wet and losing its ability to keep you warm).
Synthetic: Good to very good
Down: Not good
Weight and Compressibility
For the backcountry explorer who 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 Patagonia Micro Puff and Outdoor Research SuperStrand LT are impressively compressible and can match a down piece, while others lag behind. Fleece jackets aren’t really all that compressible, and throwing a mid or heavyweight fleece into a pack can make for a challenging endeavor.
Synthetic: Good to excellent
Fleece: Not good
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. The durability of a fleece on the other hand is usually quite good. They’ll pill up over time and it’s possible to put a hole in a fleece by snagging it on a sharp object or catching a wayward campfire spark, but they’re typically abrasion-resistant and long-lasting in general.
In addition to the insulation, it’s important to consider the durability of your jacket’s shell fabric. 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. For example, a jacket like the Patagonia Down Sweater has a great combination of sufficient toughness (20D) and minimal bulk, while the Micro Puff’s 10-denier shell is too fragile for heavy use.
Fleece: Very good
Down, Synthetic, & Wool: Varies, but can be good
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.
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 hardshell or ski jacket. 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 or Patagonia Down Sweater), 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 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 Arc’teryx Atom Jacket (which features three total pockets) as opposed to the lightweight Black Diamond Coefficient Hoody, which has only one chest pocket.
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.
In 2023, many consumers are factoring sustainability into their purchasing, and there's a lot of considerations to be made when selecting a midlayer. Among down, synthetic, fleece, and wool options, none are without blame; but there are steps that outdoor companies are making to lessen their footprint and make positive changes for our planet.
In terms of down and wool, keep an eye out for certifications like the Responsible Down Standard and Responsible Wool Standard, which ensure that ducks, geese, and sheep are treated humanely and in accordance with strict animal welfare and environmental standards. Synthetic insulation and fleece, on the other hand, are petroleum based and can contribute to greenhouse gas emissions and potentially unsafe work environments, so we encourage shoppers to look for recycled—and recyclable—materials. Whether you choose a midlayer made with synthetic or natural fibers, you can also do your part by following the three R’s: reduce your consumption, reuse what you have, and purchase products made with recycled materials. Finally, when you can, seek out used options rather than buying new.
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.
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