Your layering system can be the determining factor between a bad day and a good day outdoors, whether hiking, skiing, or hunting. We’ve done the research — and testing — to find the best base layers of 2020.
Base layers are an inevitability if you plan on recreating in any season that’s not summer. Whether you’re tackling a 14er in cool weather, hitting the slopes, or just going out to walk the dog on a frigid day, quality base layers can mean the difference between hypothermic feelings or comfortably navigating your day.
Our advice is to get the best base layers you can afford. Merino wool tends to be a top performer, but yak wool and a few other wool-synthetic blends can also be great performers in extra-cold environments. Compared to synthetics, wool has a bonus of holding warmth even when wet. It’s also the best for beating back scent for long periods of time.
But synthetic fabrics have a lot to offer. They’re often more affordable. And while you tend to give up some odor control, synthetics are the fastest-drying base layers. Fabric options like Patagonia’s well-regarded Capilene are a top choice for aerobic activities where you will work up a sweat thanks to their quick-drying properties.
Read on for our top picks for best base layers for women in 2020.
Best Base Layers for Women
Best Overall Top: Smartwool Merino 250 Base Layer Crew Top — Straight & Plus Sizing
Smartwool is ubiquitous in the world of base layers, and this top is the top-selling base layer for women from REI’s site. You’ll find 100% merino in this best choice, and that’s just because it works so dang well. Women love both the fit and feel of this easy-going crew, and the fit is right on target. This is also a size-inclusive piece, as it’s available for plus size women in 2X and 3X.
After weeks of wear, we can attest that this base layer is a top performer. We especially love the softness and next-to-skin comfort of this base layer, as well as the ease of layering.
The Smartwool Merino 250 ($100) keeps you warm but isn’t overly warm. I’ve worn dozens of midweight layers, and some of them border on too warm for average winter temps. The Smartwool 250 performs beautifully across temp ranges and is one of my go-to choices for higher-intensity winter activities like skiing.
What customers said: “Perfect fit, aesthetically pleasing. Soft and comfortable. Doesn’t itch. Soaks up sweat on hard hikes but washes out so no sweat stains leftover! Would absolutely purchase again and recommend.” — Schisticlees
Best Overall Bottoms: First Lite Kiln Long Jane
Can I live in my First Lite Kiln Long Janes? The answer is yes, and I have. I’ve worn these feminine long johns for days on hunts, only to find that they stave off body odor better than any other I’ve tried, even after hours of hiking and packing.
They’re my favorite fit of any base layer I’ve owned. High-waisted, soft, and with seams in the right spot to avoid backpack misery — these leggings ($90-95) are made for women. And though First Lite is a hunting brand, it offers base layers in solids for those of you who might not need camouflage in your life.
Merino rules the day, and these are opaque enough to wear as a first layer on warmer days with no issues. With an 18.5-micron, 250g merino and spandex woven fabric, these are a true midweight pant. But in my humble opinion, they’ll get you through the great majority of cold situations no problem. I’ve worn mine for a few years, and they feel practically new. Dreamy, you guys.
What customers said: “Outstanding leggings. True to fit. Minimal compression fit. Super comfortable. Soft to the touch. I am 5’5, with an athletic build and weigh about 135lb. Medium is a perfect length and fit for me. Material is medium thickness and warm. Wicking and antimicrobial system is on point. I will buy these in every color.” — InspiredByNature
Best Overall Hoodie: First Lite Kiln Hoody
Hoodies are either your jam or not. I like to wear hoodies when I know I want a second layer to keep my head warm beneath a hat or when the weather isn’t bad enough to require a shell hood. When I need a midweight hoodie, I grab my First Lite Kiln Hoody ($115-125). I can repeat a lot of what I said about the Kiln bottoms. This thing just beats back odor, wicks and breathes like magic, and fits in a way that eliminates bulk.
Like the pants, if you caught me wearing my Kiln Hoody, you’d likely think it was a new purchase. Fewer washes beget longer use times. I’m into it. Another benefit to remember with paying more for wool is that, if you get wet, you still retain heat. Synthetics might dry faster, but the warmth merino offers is a real big plus.
What customers said: “In the winter I live in wool base layers since I work outside in cold conditions. I’ve owned merino base layers from all the top brands and I have to say I am very impressed and happy with the First Lite merino base layers I’ve bought. The material is excellent and the design is great. I love the long sleeves and thumb loops.” — Heather Krauss
Best Budget Set: PISIQI Thermal Underwear Set
As a broke college student, I couldn’t afford high-tech gear, so I turned to a cheap base layer set ($20-23) to get me through ski season. And they performed their job for years. So in honor of those times, I sought out the top-reviewed thermal underwear on Amazon Prime. With over 1,700 reviews and a 4.6-star rating, this PISIQI set is a very affordable and well-loved performer.
Don’t expect uber-durability, but if base layers are something you need a few times a year, this looks to be a great option with an even better price tag. Made of ultrasoft polyester, these are purported to be forgiving with a second-skin feel.
What customers said: “I went to Alaska, everyone made fun of me for buying these saying I wouldn’t need them. Joke is on them, Glacier Bay while sailing is chilly in early May. I got my money’s worth from these as an underlay. They were soft, comfortable, fit as expected, and work beautifully with layers. Hands down, buy them.” — Tiffany
Best Budget Top: Patagonia Capilene Midweight Crew
It almost feels odd to put a Patagonia piece as a budget pick, but the Capilene Midweight Crew ($50-59) is an affordable gem that will last a very long time. Offered in a variety of colors and patterns, you’ll likely find one that will fit your vibe.
I will say Patagonia’s Capilene isn’t quite as odor-forgiving as merino, but it still holds up well and fits well too. And the wicking properties are exceptional. Capilene dries quickly, and Patagonia’s move to include recycled content in its clothes makes this a feel-good option for the sustainable-minded.
What customers said: “I bought this for a hiking trip and never wanted to take it off! The shirt is a comfortable material, great and flattering fit (not too snug but not too big), lightweight, and easily layered. I really like the thumb loops at the ends of the sleeves to keep the shirt from moving when layering.” — Elizabeth B.
Best Budget Bottom: REI Co-op Midweight Base Layer Tights
For only $50, you can own one of the most loved base layers out there. These have a 4.75-star rating, a few patterns to choose from, and a ton of fans. The polyester-and-spandex fabric ensures wicking properties and comfort, and women love the high-rise feature of these pants.
These pants (which also come in a top and set) are a great option for those who camp in every season, and they’re durable to boot. I’ve worn these for full weeks at a time doing trail maintenance and heavy hiking, and they worked out great. They are super easy to slip on and off and are a great layer option for those who might run cold and want reassuring warmth at night when the temp drops.
What customers said: “I wear them with a sweater on dreary days, I wear them on the slopes, I wear them as I tuck into a sleeping bag at night. All-around comfort and fits perfect.” — Concrete
Best Plus-Size Bottoms: REI Co-op Lightweight Base Layer
I was pleasantly surprised to see REI has plenty of offerings for base layers for plus-size women, between Smartwool and the REI Co-op brand. And the affordability and positive reviews on these bottoms ($28-40) make them a shoo-in for gals that I know have often felt left out of the world of athletic clothing.
This is a lighter base layer but will get you through a ton, with a fitted poly-and-spandex mix. If you want to level up and go merino, check out Smartwool’s $100 offering of its 250-weight legging.
What customers said: “I’m a plus-size gal with hips, and it’s always hard to know if sizing will work for me or not. This material is wonderful and seems like it would be able to accommodate a large range of shapes. I got these (the tights as well as the tops) to sleep in, and I’m just super impressed. Totally comfy, love the material, and even though they’re lightweight, I stay plenty warm.” — Jiffle
Best Heavyweight Top: Duckworth Powder High Neck Top
Made of merino wool fleece, reviews tout the cloud-like feel of this sweater-like base layer ($150). Eliminating the need for a gaiter, the turtleneck adds functional fashion. With a front pocket and a few classic colors to choose from, this piece can be worn casually or in action on the slopes.
The high price tag begets the fact that Duckworth’s clothes are made in the USA from sheep raised and sheared in Montana. There’s a true farm-to-fit story behind the brand’s clothes. And man, do they last. I beat up a pair of Duckworth base layers for 6 years on the regular before they bit the dust.
What customers said: “I now have three of these sweaters, one reserved for work and two for home and hiking. They are so cozy and comfortable, they can handle sweat without smelling, and they are nice enough to wear out to my favorite brewery!” — Cara
Best Heavyweight Bottoms: Sitka Gear Heavyweight Bottoms
Another hunting brand makes it on the list. Unfortunately, these bottoms aren’t offered in solids. But they’re awesome. And I’ve had trouble finding a decent pair of legitimately heavyweight base layers for the coldest times until these hit my kit. For most of us in most climates, midweight layers will do the trick. But if you’re seeking out the warmest base layers possible, consider the Sitka Gear Heavyweight Bottoms ($99).
These are made of a heavyweight fleece with a sweatpants-like feel. The rise is a little lower on the hips, but for the most part, these pants stay put. This polyester-elastane blend also does a pretty good job combating odor using Polygiene technology. And when the weather gets cold (and skiing or hunting isn’t on the docket), you can find me drinking coffee in these in my apartment, or wearing them under bibs for winter errands.
Best Half-Zip Base Layer: Kari Traa Rose Half-Zip
Merino continues to dominate, and the Kari Traa half-zip brings a classic ski lodge feel to the list. Offered only in fashionable Nordic patterns, this 100% merino half-zip ($110) has a feminine touch with an athletic makeup. Developed by an Olympic skier, Kari Traa’s base layers also have amazing design features like underarm gussets and a more athletic fit around the shoulders and hips.
One of our editors was really impressed after testing out the Rose Half-Zip. It performs super well doing laps on the slope, and the zipper never jabs or digs into your skin (just make sure you get the right size). During spring skiing and late-winter seasons, you can also feel great shedding your hardshell and retaining warmth with this layer. And you’ll look great too.
What customers said: “I love my merino kari traa huddy — the material is really pleasant to wear — soft, but most of all [works] and protects in bad weather. It’s easy to wear with pride as it looks gorgeous.” — Alexandra S.
Best Wool Blend: Black Diamond Solution 150 Merino Base Crew
Black Diamond uses a wonderful merino wool blend called Nuyarn in its Solution 150 Merino Base Crew ($120), and multiple members of our testing crew love the material.
Nuyarn gives users the best of both worlds, with the odor resistance and soft hand of merino combined with the durability and quick-drying nature of polyester. It’s a simple design of this fabulous fabric, featuring just thumb holes to keep the layer in place on the arms when pulling over second layers.
What customers said: “The fabric is comfortable, moves with you, soft, and the advertised sizing is accurate … I also used multiple days in a row and the stink was to a minimum – the wool did its job at ensuring the person next to me smelled worse!” — SAR Alexis
Best of the Rest
Kora base layers are made out of yak wool, and this stuff performs. It’s pricey at $145, but only a bit more pricey than merino, and it tends to be warmer for less weight. In my experience, that’s a bit of a toss-up unless the weather is really cold. I tend to use my kora layers as heavyweights rather than midweight, as they’re just a bit too warm for early-to-mid fall for what I’m up to.
This crew is a constant in my winter kit. It’s thin enough to easily go under sweaters or fleeces for added warmth, and it’s nice enough to wear on its own with a vest on warmer days. Yak wool really does pack a warm punch. If you’re doing legit stuff in cold weather, invest in kora.
The Vertex leggings by icebreaker ($130) are made for movement, and women love these leggings for a myriad of reasons. Once again, made of merino, these are certified by the Responsible Wool Standard, upping the expense but setting welfare issues at ease.
Reviews state that these are soft and lack the itch of previous products. They are only offered in print, but it’s an apres-ski-friendly kind of print.
What customers said: “I am always cold in winter so have been on the hunt for comfy pants that are also warm. These are the best I’ve found, so I have bought them in both colors! I’m also super sensitive to itch and these are even less itchy than other Icebreaker products I have.” — CIWaldron
REI Co-op Lightweight Base Layer Top — Straight & Plus Sizing
A runner-up for the budget pick, this top is available in straight and plus sizing, from XS-3X. And gals of all sizes really do love this shirt. I love that pricing ($40) doesn’t change from one garment to another. Nice work, REI.
A soft poly-and-spandex blend makes this piece comfortable and wicking to wear. It’s a nice enough shirt that you can wear it on its own in public or under a fleece on a mountain outing.
What customers said: “I bought two of these tops to use as a base layer, but I wore one just as a regular top to hike 2.5 miles on a cool humid day with the temperatures in the mid-50’s. Although I kept up a fast pace on my hike, I never felt sweaty and the top quickly wicked away any sweat while keeping me warm enough to not need a jacket. Thanks so much REI for offering technical clothing in women’s plus sizes!” — TGirl
How to Choose the Right Base Layers
With so many base layers to choose from, how do you choose the right base layer combo for you? And how do you utilize base layers for ultimate effectiveness? We’ve got a handy how-to for you below.
Choosing the Right Fabric
Really, it comes down to what you can afford and what activities you do. Synthetics are highly durable, high-wicking, and have some odor-beating technology. Merino is less durable, but it has temperature-regulating features that can work in a wide range of weather, and it also wicks well. You might notice that I left silk off this list. Silk needs a lot of washing, is very thin, and not very durable.
Most of the base layers on this list are a majority-wool blend, or polyester-and-elastane blend — in short, choose the one that works best for you.
The weight of the fabric you choose is also important. Most people will do well with a pair of simple midweight base layers. If you’re perpetually cold, grab a pair of heavyweight base layers. If you’re buying base layers to backcountry ski, run in, or for any other intense activity, go light. Easy peasy.
How to Wear Base Layers
Base layers — as their name implies — are meant to be worn as the base of your clothing system, next to your skin. If you pile on cotton underwear and a cotton T-shirt under your base layers, you’re negating all the ways a base layer is intended to work. Most base layer bottoms are intended to be worn as long underwear.
Of course, for us gals, bras are often a necessity. So don’t make the mistake of wearing a non-wicking bra beneath your base layers. Find yourself a sports bra that fits, wicks, and supports to combat sweat and chills on your upper half. Then let any of these base layers work their magic!