Best Merino Wool Base Layer: Keep Warm and Cozy

Woman in merino wool shirt
Written by Dennis Owens

It’s the time of year when the snow is plentiful but in a few months it will be gone and new outdoor activities will beckon. Right now, however, the big question is this, what is the Best Merino Wool Base Layer?

You’re heading out to the slopes, skis or snowboards in tow, looking forward to an epic day on the slopes, the moguls, and the jumps. But it’s only epic as long as you’re warm, comfortable and dry. That’s where Merino – the ultimate wool – comes in to take you to an entirely new level of comfort.

The Merino sheep was first noted in Spain where the King had a closely guarded monopoly on this fine wool and theft of any of the Royal Merino Flock was punishable by death. Fast-forward to the late 1700’s and Merino sheep were introduced to Australia.

Hiker in merino wool shirt

Through selective breeding, increasingly finer wools were developed. These finer fibers moved the wool garment trade from the farm to the Haute Couture circles where it has remained a key luxury fabric.

Today, New Zealand also has a robust Merino wool production industry. Several of our picks for this list of best Merino wool base layers have imported or sourced their wool from New Zealand which has some of the finest wool in the world.

Some of the wool can even be sourced to a particular flock! As you will see, this versatile material has outstanding properties of warmth, comfort and sustainability.


With a variety of high caliber offerings in the base layer department, check out these top picks and their attributes, technologies, and designs.

Merino365 Long Sleeve Shirt

Merino 365 New Zealand 100% Merino Longsleeve Baselayer

Shipping Weight: 8.2 ounces

Star Rating: 4.5 stars

Specific Features:

  • Warm when it’s cold and cool when it’s hot
  • Renewable and biodegradable
  • Hypoallergenic and super soft
  • Machine washable in cold water
  • Holds shape without stretching
  • Anti-bacterial and fire-resistant
  • Provides UV protection and SPF 50+

Lucy Wildman, is passionate about Merino wool and her family, including her American husband and two children, wear it every day.Based in New Zealand and Fiji since 2008, their business, Merino 365, evolved from a desire to outfit their kids in long-lasting, durable yet soft clothes that were both renewable and biodegradable and a shared interest in snowboarding and fabrics and layering techniques. As Lucy says, “It seemed like a natural fit to introduce Merino to our friends and friends of friends and the rest of the world!”

This long sleeve shirt is a great base layer for all types of outdoor activities. If you’re an outdoors enthusiast the shirt features generously cut thumb-loops that allow for extra coverage during frigid weather. As a small family business, Lucy says, “We are actively involved in every single step of the process…so we met with our pattern maker and made sure the position and size of the thumb loops were exactly where it needed to be.”

Merino 365’s shirt, with its ability to regulate temps and keep you drythrough the admirable wicking ability of 100% New Zealand wool, is perfect for hunters and fishermen as well as the go-to material for snowboarders and skiers, hikers and climbers. Factor in those super-sized thumb loops keeping your hands warm you’ll also be dressed to impress! Merino365 feels soft next to your skin and takes comfort to a seriously higher level.

Another big plus is that this product is produced ethically, is biodegradable and environmentally friendly. Stacked up against poly-based fibers there’s just no comparison. With a range of colors from gunmetal gray to light gray and from sky blue to deep blue, and a stripedlight and dark gray shirt to round out your options.

This outdoorsman’s underlayer of 100% Merino wool from one of New Zealand’s South island farms, is sourced directly and overseen from farm to finish and the folks overseeing the flocks are easily able to pinpoint which flock the wool came from.

Check the price on Amazon


Woolx Men's Merino Wool Base Layer Bottoms

Shipping Weight: 1 pound

Star Rating: 5 stars

Specific Features:

  • A waistband that won’t roll
  • No interior tags
  • Flat seems for optimal mobility
  • Super soft feel of the no-itch material

Did you know that the one-third of your body surface area is encased by these super heavyweight bottoms? Keeping your lower extremities warm is serious business and these bottoms make for an extremely warm base layer.

How warm, you ask? Woolx is guaranteeing these are the warmest base layers on the market and they have tested this premise during the 2018 Iditarod under extreme conditions in the backcountry of Alaska.

Featuring a variety of color choices including “new black,” these thermal Glacier Merino Bottoms deliver it all with impressive warmth and great design elements. Heavy duty insulation even when wet, plus moisture wicking and anti-microbial and odor-free properties will take care of sweat by moving it to the top layer of fabric where it evaporates. These bottoms are base layers worthy of athletes, outdoorsmen and anyone who is serious about keeping fit, staying active and taking on new challenges.

More about Merino – With “fine” fibers measuring under 24 microns in diameter, WoolX only uses “superfine” Merino fibers coming in at just 19.5 microns in diameter. This means the base layer bottoms you buy will feel silky against your skin, not scratchy or itchy. Super crimped individual wool fibers allow for both natural stretch and return to original shape.

By providing great performance in cold weather with top-notch insulating properties and highly efficient moisture wicking these bottom layers are durable and solidly grounded in exceptional comfort.

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Minus33 Merino Wool Women's Franconia Midweight Bottom

Shipping Weight: 1 pound, generally ships within one business day

Star Rating:  4.5 stars

Specific Features:  

  • Women’s sizes XS to XXXL
  • 100% Merino wool
  • Lock flat seams for comfort
  • UPF rating of 50+
  • Machine wash and dry

Minus 33 is a New Hampshire based company with a history in textile manufacturing going back 101 years. Four generations of experience with Merino wool means that these guys know their stuff and are dedicated to bringing great pieces to the retail market for die-hard outdoor enthusiasts and for people who just want fine Merino wool fabrics next to their skin or as additional layers such as the women’s mid-weight bottoms featured here.

Owner John Glidden, a textile engineer, and Operations Manager Joel Schweizer explained that the family business has roots dating back to 1916 with the incorporation ofL.W. Packard, Inc. a textile manufacturing company that made heavy fabrics for ladies coats. Minus 33 is the highly successful offshoot of this company, headquartered in one of the original mill sites in Ashland, NH.

According to Schweizer,the company sells about 100,000 pieces per year and works with 700 upscale retailers across the country. As “outdoor specialists” featuring Merino wool garments, in addition to individual salesthey have engaged with law enforcement and large companies that require the very best work-wear for their outdoor employees.

Minus 33 sources its Merino wool from Australia’sprimarily white sheep flocksallowing for the brilliant color choices available after dyeing–including black, charcoal, cream, red and radiant violet the line has pizzaz! While the pieces are assembled in China the wool is 100% Merino. Features of the brand include a knit interlocking structure overall and cuffs with stretch rib knit for a great stay-put performance. Heat applied logos and easily removed care tags add to the no-itch wear factor.

Women love these bottoms because they are perfect for use as 3-season apparel or as base mid-weight layering. The wool wicks away moisture from the skin so it can evaporate quickly andin the unlikely event that the wool catches fire it will extinguish naturally while synthetics can melt and stick to the skin. The women’s Franconia mid-weight bottoms, a best seller at Minus 33, have an inherent flexibility for easy movement and the super soft comfort of renowned Merino wool.

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Pearl Izumi - Ride Men's Transfer Wool Long Sleeve Cycling Baselayer Tops

Shipping Weight: 11.7 ounces

Star Rating: 5 stars

Specific Features:

  • 86% Merino wool and 14% nylon
  • Fits anatomically close to the body
  • 4-season use
  • Excellent in wet weather

While Pearl Izumi is primarily a cycling line, headquartered in Louisville, Colorado, they do produce garments that include both natural wool and a small percentage of synthetic material and can do double duty as base layers.

The Pearl Izumi story dates back to 1955 in Japan and their dedication to pioneering new materials and garments for the cycling world is legendary.

As is the case with the Ride men’s cycling base layer top featuring a Merino wool shirtfront with a wool/poly mesh back panel that allows for serious ventilation options. Add to this the quick transference of moisture, a fast drying time and odor dispersal and you’ve got a year-round garment that can be used alone or in a number of base layer configurations.

In addition to being a solid shirt at any point in the year, this is a cycler’s dream shirt. It regulates temperatures in cold weather and is comfortable and stylish. The design of a rotating construction on the sleeves is also optimal for cyclists.

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Helly Hansen Men’s HH Warm Ice Crew

Helly Hansen Men's HH Warm Ice Base Layer Long Sleeve Crew

Shipping Weight:  8 ounces

Star Rating:  5 stars

Specific Features:

  • 57% Merino wool and 43% polypropylene
  • Inner Lifa stay dry technology
  • Outer layer of Merino wool for comfort and warmth
  • Lifetime limited warranty
  • Non-itch and 215g/m2
  • Imported 100% wool
  • Regular fit Men’s long-sleeve crew for winter conditions
  • Friction reduction with low-bulk cuffs and flatlock stitching

Based on the original Helly Hansen design for menswear, and continually re-designed over the past four decades, this is the go-to long sleeve crew for men who stay active and love the outdoors. Perfect for aerobic exercise the garment supplies plentiful warmth and insulation along with superior moisture wicking. HHDry lifa is unique to all Hely Hansen base layers and provides lightweight breathable high-performance material for all seasons.

Helly Hansen has been a force to be reckoned with since 1877. It all started off with the husband and wife team of Helly and Margrethe who made waterproof oilskin jackets. From these early beginnings, the brand has evolved and engineered many new innovations for protection from extreme outdoor temperatures as well as cutting-edge and fashionably chic pieces that can be worn as part of full gear or around the house for top-notch comfort.

Imported Merino wool combined with non-itch Lifa, HH’s registered trademark for their proprietary polyester fabric, can be seen on ski professionals, mountaineers and more. The long sleeve crew comes in a variety of colors and color combinations and can be worn as an under-layer complete with an outer-layer of Merino wool for softness, warmth, and comfort.

Now headquartered in Oslo, Norway, Helly Hansen provided base-layers for the athletes of the U.S. Ski and Snowboard Association and in particular the U.S. Alpine Ski Team during the 2012 Sochi Olympics. Helly Hansen was acquired by takeover in 1997 and has had two subsequent acquisitions while still retaining its high-performance and innovative new products. A worldwide company with 800+ employees the company also specializes in survival and rescue gear.

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Helly Hansen Women's HH Warm Base Layer Pant

Shipping Weight:  One pound

Star Rating:  4 stars

Specific Features:

  • 57% Merino wool and 43% polypropylene
  • Imported anti-itch Merino wool
  • HH Warm keeps you dry
  • Lifa T3 hollow fiber technology

Stylish colors and a dozen colors and patterns to choose from make this line-up one to take notice of. As great looking as a base layer around the house as it is comfortable these fun and fabulous pants for women make a statement. Three-layer technology creates extremely effective protection from the cold, wind and rain.

A base layer insulates and contains any moisture, while the HH Warm layer wicks moisture away to the outer layer thereby maintaining body temperature. According to Helly Hansen, this 3-part system is reputed to imitate the fur of polar bears! The Lifa T3 poly-mesh moves moisture out while a super soft layer of Merino wool keeps you warm without itchiness.

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Wrap yourself

Now that you have laid out the best merino wool base layers to chose from, it will be easier for you to make your pick and be sure that your body will be satisfied with both the warmth and the cool sensation merino wool offers. Have we missed anything? Let us know in the comment section!


Dennis Owens

Dennis Owens is a graduate of National Camping School and REI Outdoor School. He knows everything about what gear to take with you, how to plan your trip to stay safe and what to do if you get lost in the mountains. We are lucky to have Dennis with us as he is a ‘walking encyclopedia’ when it comes to the wilderness.