Finding the right base for your layering system is key to having a good time on the trail. In fact, if you’ve ever found yourself overheating or freezing, feeling damp and sweaty, or getting chaffed, you may not be wearing the right base layer. Base layers that are too heavy may impede movement, while those that are too lightweight may not be warm enough.
Our top choice is the Smartwool Classic Thermal for Men and Women. Made for just about any outdoor sport, this option is high quality, extremely wearable, and will soon be your favorite base layer.
We’ve also got picks for the most versatile base layer, the most affordable, the warmest, and the best value for the price. Read on to see our picks.
Our Top Picks for Hiking Base Layers
Best Overall: Smartwool Classic Thermal Merino Crew Men’s and Women’s
The Smartwool Classic Thermal Merino Base Layer emerges as one of the best hiking base layers, leveraging exceptional merino wool fabric to remove moisture for a superior warmth-to-weight ratio.
Merino is a super soft natural material that effectively manages moisture by pulling sweat away from the body, keeping the wearer dry and comfortable throughout the day. This merino wool base layer also provides insulation in cold-weather conditions while remaining breathable.
Its odor-resistant properties make it a go-to for all-day wear, ideal for multi-day hiking trips where laundry facilities may be limited. Merino wool layers offer odor resistance and are more durable than synthetic material.
This quality base layer is made with flatlock seams to prevent chaffing, making it suitable as both a base and middle layer. Its drop-tail hem provides added coverage and warmth, while thumb loops offer a way to keep your hands and wrists warmer and hold your sleeves down when moving around.
Whether worn alone in warmer conditions or as part of a layering system in colder climates, this base layer excels in providing reliable performance in a wide range of conditions, making it a go-to choice for outdoor enthusiasts seeking top-tier comfort and warmth.
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Most Versatile: Black Diamond Solution Wool Half Zip Hoody Men’s and Women’s
The Black Diamond Solution Wool Half Zip Hoody stands out as a top contender for the best hiking base layers thanks to its versatile design. Crafted from soft wool and polyester, this option offers superior moisture control, ensuring that sweat is efficiently pulled away from the skin to keep you dry and comfortable while outside. It’s suitable for use in various weather conditions, including winter hikes.
Constructed with a strategically placed shoulder panel to prevent chafing, the Black Diamond Solution Wool Hoody also offers practical features like thumb loops and a longer trail hem. The integrated thumb loops help keep sleeves in place, while the long hem offers added coverage and protection, especially when bending or stretching during hikes. Such thoughtful details contribute to the overall comfort and usability of this base layer, and the hood adds extra warmth and protection from wind.
This breathable base layer is made from innovative Nuyarn Merino stretch wool technology, making it ideal for high-output activities like hiking, backcountry skiing, trail running, or rock climbing because of its lightness. While the wool-blend construction may not be as durable as synthetic fabrics, the Black Diamond Solution Wool Hoody compensates with its warmth-to-weight ratio and odor-resistant properties.
It’s a reliable choice for hikers seeking a lightweight yet effective base layer. Whether worn as a standalone outer layer in warmer conditions or as part of a layering system in colder weather, this option delivers consistent performance and comfort.
The inclusion of a half zip offers extra warmth or cooling when needed. Despite being on the pricier side and requiring a few washes for optimal comfort, its performance across various metrics makes it a go-to choice for outdoor enthusiasts.
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Most Affordable: Helly Hansen LIFA Stripe Men’s and Women’s
The Helly Hansen LIFA Stripe Crew is a timeless classic and one of the best and cheapest base layers for hiking, with a design that combines form, function, and affordability. It’s entirely made from LIFA, an ultra-lightweight fabric that delivers light insulation and manages moisture through single-layer LIFA fibers. The technology wicks away moisture superbly, making it a breathable base layer that keeps the wearer dry and comfortable while hiking.
While it may lack the trendy features found in more expensive products, such as wool blends, the Helly Hansen LIFA Stripe Crew is a practical option for someone looking to save money but still stay warm. Its simplicity, durability, and exceptional moisture-wicking capability make it a versatile choice for hiking, climbing, biking, and other outdoor pursuits.
It has a snug fit and lightweight design to ensure comfort and mobility, while its durable construction and synthetic fabric mean it can withstand the rigors of the outdoors.
The Helly Hansen LIFA Stripe Crew is a great choice as a functional base layer that is low-cost but still offers exceptional moisture-wicking capabilities. Its versatility, reliability, and ability to manage body heat well make it a go-to choice for hikers wanting to save some cash.
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Best for Warmth: Icebreaker 260 Tech Long-Sleeve Crewe Base Layer Top Men’s and Women’s
The Icebreaker 260 Tech Top is a prime example of Icebreaker’s dedication to producing high-performance gear while prioritizing ethics and the environment throughout the supply chain. Constructed from 100% merino wool, this is a mid-weight base layer with plenty of warmth. The snug fit designed with offset shoulder seams and forward-set side seams ensures comfort and mobility, making it suitable for high-intensity activities such as hiking and snow sports.
It also features a convenient drop-tail hem for added coverage and warmth.
The Icebreaker wool base layer excels in moisture-wicking and is particularly beneficial for hikers embarking on multi-day treks or thru-hikes in cooler weather or winter. Sweat is efficiently managed, preventing discomfort and chafing, even during intense physical exertion.
While we’d recommend this for cooler temperatures, hikers can rely on the layer’s breathability to regulate their body temps in warm weather as well.
The odor-resistant nature of wool base layers makes them an excellent choice for extended hikes where access to laundry facilities may be limited. Merino wool’s natural antibacterial properties allow for extended wear without the worry of odor buildup.
The Icebreaker base layer also offers UV protection with UPF 20 fabric. The fit and offset shoulder seams prevent pack rub, ensuring comfort during extended wear. The long hem provides added coverage, the flatlock stitching helps prevent friction, the offset seams provide a soft next-to-skin feel, and the gusseted underarms mean you can move around without restriction.
One of the standout features of Icebreaker products is the brand’s commitment to sustainability and ethical practices. From the selection of merino wool to the treatment of workers throughout the supply chain, Icebreaker prioritizes environmental responsibility and human and animal welfare.
Icebreaker’s base layers are machine washable and quick drying in the shade. Despite repeated wear and washing, they retain their softness, warmth, and overall quality, making them a long-lasting investment.
For merino base layers, it’s hard to beat Icebreaker in terms of versatility, durability, and environmental consciousness.
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Best for Sun Protection: REI Co-op Midweight Half Zip Men’s and Women’s
The mid-weight base layer from REI Co-op combines warmth, stretch, durability, and affordability, making it a solid choice for those seeking simplicity and functionality. Made from a mid-weight blend of 92% polyester and 8% spandex, this base layer offers an impressive UPF 50+ rating, four-way stretch, and flatlock seams for added comfort.
Available in both crew top and bottom styles for men and women, they are designed to fit snugly against the skin, providing excellent coverage and freedom of movement. The crew-style neck and flatlock seams prevent bunching and chafing, making it suitable for extended activities like hiking or everyday wear during colder weather.
The tailored fit around the shoulders allows for comfortable layering under a pack, while the fabric’s moisture-wicking properties and added stretch from the spandex mix ensure plenty of comfort even during intense hiking.
The synthetic fabric of REI’s base layers effectively traps body heat while allowing for breathability, making it suitable for layering, but it may be more prone to odor than wool blends. While merino wool remains a popular choice for its natural moisture-wicking properties and soft feel, REI’s synthetic base layers offer a compelling alternative for hikers looking for lightweight options with quick-drying capabilities.
In comparison to other more expensive base layer options on the market, the REI Co-op mid-weight base layer definitely holds its own, especially thanks to its UPF 50+ rating. The synthetic fabric holds up well even after multiple washes, showing no signs of thinning, snags, or unraveling threads. This longevity, combined with the budget-friendly price point of just over $60, makes the REI mid-weight base layers a cost-effective investment for hiking.
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Best Synthetic: Patagonia Capilene Midweight Men’s and Women’s
The Patagonia Capilene Midweight Crew is our favorite synthetic base layer for hiking. It’s perfect for hikers who want the durability and lightness of a synthetic and the odor-free properties of wool. Its slim fit and soft fabric provides a second-skin feel, ensuring unrestricted movement and comfort while hiking.
Constructed with a blend of recycled synthetic materials and the lightest-weight fabrics, this base layer excels in its moisture-wicking capabilities and ability to manage body temps—a durable combination for strenuous hikes. Patagonia uses HeiQ Fresh technology to keep your base layer feeling fresh and prevent you from needing to wash it every day.
While merino wool base layers are often favored for their natural fibers and odor control, the Patagonia Capilene offers comparable moisture-wicking and odor-control properties with the added benefits of durability and quicker drying times.
The king of synthetic base layers, the Capilene Midweight Crew also offers thumb loops to keep sleeves in place and provide additional coverage for the hands and wrists, while gussets under the arms prevent chafing during extended hikes. The inclusion of a longer hem in the back adds to its practicality, offering coverage and staying tucked in during active pursuits.
The Capilene Midweight also has plenty of features to prevent chafing, like flatlock seams, a rib-knit collar with internal neck tape, raglan shoulder seams, and offset side seams that will lay smoothly beneath pack straps. Another bonus is that this base layer contains recycled materials and is crafted with Fair Trade Certified sewing—and, since it’s Patagonia, you get the lifetime guarantee.
Whether hiking in warm weather or braving cold conditions, the Patagonia Capilene Midweight Crew is a go-to base layer for hikers seeking lightness and durability, as well as odor control.
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Buyer’s Guide: How to Pick a Base Layer for Hiking
When picking a base layer, look at some of the key features, such as thermal weight, fabric, fit, wearability, durability, and, of course, price.
Fabric
When it comes to staying dry and warm during outdoor activities, cotton is a big no-no. As the saying goes, “cotton kills.” Cotton’s ability to absorb water makes it a poor choice for outdoor pursuits, cooling the body 25 times faster than air and leaving wearers cold and uncomfortable.
Merino wool base layers offer a natural solution. Merino sheep, with their super fine and highly breathable fleece, have evolved to endure extreme temperatures, providing natural insulation and ability to manage moisture.
These properties translate seamlessly into merino wool base layers, offering temperature control, breathability, some UV protection, and odor resistance.
Use
When picking a base layer, consider where you might use it and adjust thermal weight as needed. For instance, if you’re planning a brisk hike in mild temperatures, a lightweight base layer made from merino wool or synthetic materials would suffice.
On the other hand, if you’re gearing up for a high-intensity outdoor workout or facing extreme cold conditions, opt for a heavier base layer with advanced insulation features. Consider options with high loft or brushed interiors for maximum warmth and moisture control during intense activities or in harsh weather.
Comfort
Fit and comfort are important when selecting clothing for being active. Whether you’re skiing down slopes or hiking for days at a time, a layer that fits snugly without being restrictive ensures optimal moisture control and insulation. Look for features like flatlock seams to minimize chafing and irritation during extended wear.
Keep in mind that you’ll need to be able to wear your base layer with other layers. To determine which one will integrate well into your layering system, consider the fabric and design. Look for a slim fit and longer length in the back and consider features like a hood and whether they will fit with your jacket well.
When selecting a base layer, envision how it will fit alongside your other garments. For example, a mid-weight layer with moisture-wicking properties is ideal for winter sports like winter hiking or skiing.
When hiking, you’ll want to combine your base layer with thermal mid-layers and waterproof outer shells to provide insulation and protection against snow and wind.
Also check out our comprehensive guide to layering for a winter hike.
Durability
High-quality materials that withstand frequent washing and extended use without compromising performance include merino wool and certain synthetic blends. Merino wool is known for its durability, natural elasticity, and resistance to odors, making it a preferred choice for base layers.
Look for merino wool with a fine micron count for softness and itch-free wear. Additionally, consider synthetic blends engineered with durable fibers like polyester or nylon, which offer excellent durability and shape retention over time. When selecting synthetic blends, prioritize options with abrasion-resistant properties for enhanced longevity.
When assessing durability, pay attention to construction features such as flatlock seams and reinforced stitching. Flatlock seams minimize chafing and irritation during prolonged wear, while reinforced stitching makes them last longer, even with repeated washing.
Opt for base layers with seamless construction or strategically placed seams to reduce friction points and enhance comfort. Additionally, check for fabric treatments like anti-pill or anti-microbial finishes, which help maintain the garment’s appearance and freshness over time.
Frequently Asked Questions
What type of layer should I wear as a base for hiking?
The best way to choose a base layer is to pick one that feels good on your skin and that will keep you warm and/or cool enough for your hike.
Opt for materials like merino wool or synthetic blends that can efficiently manage moisture in warm conditions and control body temperature in cool weather. If you’ll be moving your upper body around a lot during your planned activity, you may want features like stretch and extra cushion around the backpack strap area.
What is the best base layer for sweating?
Choose something that effectively wicks moisture away from the skin for activities involving heavy sweating, such as hiking, climbing, or other intense workouts.
Fabrics like merino wool or synthetic material with moisture-wicking properties can keep you dry and comfortable, preventing chafing and discomfort caused by sweat accumulation.
What is the warmest base layer for extreme cold?
In extremely cold conditions, opt for a heavyweight base layer made from materials like merino wool or synthetic fabrics with excellent insulation properties and a high thermal rating.
These base layers provide superior warmth while effectively wicking moisture away from the skin to keep you dry and comfortable. Layer with a mid-layer and outer shell for added insulation and protection against harsh weather.
What is the three-layer rule for hiking?
The three-layer rule for hiking involves wearing a base layer for moisture management, a mid-layer for insulation, and an outer layer or shell for protection against wind and precipitation. The number of layers you need may vary depending on the weather conditions and your personal comfort level.
You may want to pack all three layers so you can adjust according to how your temperature changes throughout the day.
Should hiking base layers be tight?
Hiking base layers should fit snugly against the skin without being too tight or restrictive. A close-fitting layer helps efficiently wick moisture away from the skin and provides better insulation by trapping warm air close to the body.
Avoid base layers that are overly tight, though, because they can restrict movement and lead to discomfort. Also avoid ones that are too short and expose your stomach if you raise your hands.
Are base layers better than thermals?
Base layers and thermals serve similar purposes in providing warmth and moisture control during outdoor activities. The choice between the two depends on factors like fabric preference, activity level, and weather conditions.
Base layers typically refer to a broader range of lightweight garments worn close to the skin, including both tops and bottoms, while thermals often specifically refer to long underwear. Thermals are generally better for staying warm while outside and base layers are better for activities like hiking and skiing.
What is the warmest base layer on the market?
The warmest base layers typically feature heavyweight materials like merino wool or advanced synthetic fabrics with superior insulation properties. Look for base layers specifically designed for extreme cold conditions, with features like high loft or brushed interiors for added warmth and comfort and a high thermal rating and thickness.
Are base layers worth it?
Base layers are worth investing in for outdoor activities like hiking, skiing, or mountaineering, as they provide essential moisture management and insulation properties.
Quality base layers effectively wick moisture away from the skin, regulate body temperature, and provide an additional layer for mid-winter warmth without adding bulk. Whether you’re a casual hiker or a seasoned one, a good base layer will enhance your comfort and therefore enhance your day.
Ready to Make a Choice?
Choosing the best base layer can be difficult with so many options, but it’s easy to get the right one once you learn about their features. Each base layer is designed for a different person; are you a synthetic junkie or a merino addict?
Merino is great for those who want something soft that is super warm and can be worn every day. Synthetic fabrics may be more versatile and lighter, but they have to be washed more. Merino is a bit more fragile but tends to hold up well when you sweat a lot without making you feel damp. Synthetic fabrics dry quickly and tend to be more durable.
Deciding whether you want protective features against chafing, a hood, a half zip, or a crew neck can also help you choose what to buy.
Our top pick for the best all-around base layer for hiking is the Smartwool Classic Thermal Merino Crew Men’s and Women’s. Smartwool does not compromise quality, and this super-soft base layer has a wearability that will leave you addicted. It lasts a long time, doesn’t smell bad over many days, and keeps you extremely warm and dry.
Whether you’re dressing for your longest hike yet or just a quick trek, one of the base layers on our list will no doubt keep you comfortable, dry, and chafe-free on your next big adventure.
