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The 5 Best Thermal Leggings

If you live in leggings — and who doesn’t these days — you might find your go-to pair a teensy bit chilly when the mercury drops. Just as you wouldn’t necessarily rely on a short-sleeved tee all year long, it might be good to stock up on a few pairs of the best thermal leggings that provide some added protection against cold temps. Whether you’re looking for a fleece-lined pair to wear around the house, some good winter running tights, or merino base layers for your next hike, there are plenty of options out there to see you through seasonable and unseasonable weather. Not only will you stay warm, but you also won’t wear out your basic pairs as quickly.

Thermal leggings will offer a couple different types of insulation. Fleece seems to be the most common; it’s soft and quick-drying, which is essential to staying warm, and has the added benefit of being budget-friendly. You can even find pairs with super thick linings like sherpa.

If you need an active legging you’ll either want a lining of all-natural wool or a high-tech performance fabric. The benefits of wool include being famously warm and lightweight, excellent at moisture-wicking, and even naturally antimicrobial (it'll even keep odors a bay). If you're worried about itching, opt for a fine merino pair. (Most good leggings will be made from that anyway.) A moisture-wicking performance fabric, on the other hand, will make the most of your naturally generated body heat with added quick-drying capabilities to withstand the elements for outdoor workouts.

Ahead, the coziest thermal leggings that are about to become your new cold-weather basics.

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1. These Cult-Favorite Fleece-Lined Leggings With Pockets

These fleece-lined leggings are a great option for workouts and lazy days alike. The wide yoga waistband feels super-comfy if you’re lounging all day and those deep pockets on either leg are so convenient. But if you’re not into pockets, they also offer options with a clean fit. Workout-friendly features include smooth interlock seams for chafe-free reinforcement and a crotch gusset so you can move, bend, and snap with confidence. And if you plan on lounging, well, these are buttery soft for that too. "I normally drop some cash on leggings because I crave quality," one shopper wrote, adding that expensive brands "can’t hold a candle to these." Grab packs of two or three if you want to stock up. For tough-to-find inseams, the Yogipace fleece leggings are offered from petite sizes all the way to extra-tall.

  • Available options: 36
  • Available sizes: X-Small — XX-Large

2. A Pair Of 100% Merino Wool Leggings Totally Worth The Splurge

For a pair of naturally thermal leggings, you can’t do much better than merino wool. This pair has flatlock seams and tagless construction to prevent chafing. Made with 18.5-micron fine merino wool, with a weight of 230 g/m2 (grams per square meter), adding up to a mid-weight layer that Minus33 chose for its ability to keep you warm in temps as low as 30 degrees Fahrenheit if you aren’t moving much, and down to a bone-chilling 0 degrees if you’re super active. One shopper tested these on a week camping in the mountains and reported back: "These came home in great shape after a week of crawling around in the elements being worn constantly as under wear and as only wear. I literally lived in these things and wouldn't hesitate to buy another set." If you’re on a budget, the Merino.tech leggings are an affordable alternative (and come with socks!)

  • Available colors: 6
  • Available sizes: X-Small — 3X-Large

3. A High-Tech Pair Of Winter Running Tights With Compression

Under Armour is already revered for their athletic gear, and these thermal workout leggings live up to the hype. Their high-tech, dual-layer fabric maximizes your natural body heat, all while wicking away sweat and precipitation to keep you dry during outdoor workouts — and the brushed interior feels nothing but cozy. Welded seams means no stitching is involved — the fabric is literally fused together, so it's guaranteed not to chafe your skin — and the compression fit helps your body make the most of workout and recovery. "These leggings are nice and thin but at the same time provide serious protection from cold cutting wind. I have worn them outside on cold days (low 30s and "feels like" temps 28 degrees) and they worked beautifully and kept me nice and warm," a fan praised.

  • Available colors: 3
  • Available sizes: X-Small — XX-Large

4. Some Plus-Size Fleece Leggings You Can Score In Lots Of Colors (& Even As A 5-Pack)

These solidly made fleece plus-size leggings come in classic solids as well as a few hard-to-find shades like taupe and Dutch blue. No bells or whistles here: just really great leggings with a comfy waistband and soft cotton-candy fleece lining at a fantastic price. "These are the ones to try," a reviewer promised. "Easy to wear all day to work and then around the house, because they are that warm and cozy." Sold as a single pair as well as sets of two to five, you can try a pair first and then stock up.

  • Available options: 15
  • Available sizes: 1X — 3X

5. A Pair Of Sherpa-Lined Leggings That Are Impossibly Cozy

These sherpa leggings will keep you warm even in extreme cold, with the brand promising protection in well-below zero temperatures. They’re made from tightly-woven cotton and spandex for plenty of stretch, and a wildly soft sherpa lining that is definitely made for winter. More than one shopper remarked that these were the thickest leggings they'd ever owned and a go-to for chilly days. "These leggings are fantastic! I am always cold. I wore these under my ski pants and was nice and cozy. Super comfy, no roll, good fit, good stretch, and most importantly, warm," a reviewer confirmed.

  • Available colors: 5
  • Available sizes: X-Small X-Large

Also Nice: A Thermal Underwear Set With Rave Reviews

This bestselling thermal underwear set (over 19,000 Amazon ratings and counting) pairs a crewneck long-sleeved tee with leggings to insulate you from head to toe. The polyester-spandex fabric is moisture-wicking with a tagless construction and sturdy seams that promise not to itch or chafe. Four-way stretch gives you full range of motion whether you’re using them as a base layer or sprawling out for a streaming marathon. "Bought a set of these thermals in each color for my trip to Alaska," a shopper wrote. "Wore them under jeans, leggings, snow pants, depending on the activity of the day. At -14 degrees they kept me warm and they are super soft and comfortable."

  • Available colors: 11
  • Available sizes: XX-Small — 3X-Large