Feet can get overlooked when shopping for a cold-weather wardrobe, but they make such a huge impact in how cozy you feel. Luckily, the best thermal socks ensure that yours stay especially warm without much effort. Like any sock, you'll want to consider the length and material before you buy — all factors that depend on your personal needs and preferences — but for warmth-retaining socks specifically, material composition is extremely important. These are some of the most commonly used materials when it comes to thermal socks:
- Wool: This natural fiber derived from sheep's fleece is one of the best insulators. It's super warm, but still breathable and moisture-wicking, so it's great for cold-weather activities that might cause you to sweat. That said, some people do have wool allergies or sensitivities — or just prefer animal-free alternatives — so if that's you, you can opt for synthetic materials instead.
- Acrylic: Acrylic is considered a great wool alternative because it mimics wool in its feel and appearance, but it's synthetic to reduce costs and prevent irritation. It's also relatively absorbent, thick, and warm.
- Cotton: Cotton is typically affordable, skin-friendly, versatile, and easy to care for. It's not the most insulating or quick-drying fabric on its own, but certain weaving techniques help it to retain heat and dryness much more effectively.
- Polyester/Nylon: Since these plastic-derived materials are synthetic, they're really inexpensive to manufacture. They're also usually durable and moisture-wicking (especially when compared to cotton). In large percentages, you're more likely to find these materials in lightweight workout clothing, but they're sometimes used in smaller quantities as fillers in thermal items.
- Spandex/Lycra/Elastane: These terms are often used interchangeably, and in short, this material is capable of stretching up to 500% and then returning to its original shape without damage. The higher percentage of spandex, Lycra, or elastane, the stretchier your socks will be — a little can be great, but it's not always the best thing for heat-retention.
These thermal socks use different combinations of the aforementioned materials, but they've all got one thing in common: They're highly rated and effective when it comes to keeping your feet warm, dry, and comfortable.
1. The Overall Best Thermal Sock
Carhartt cold weather socks are the best overall pick for most people and activities. That's because they offer a little bit of everything — heat retention, breathability, cushioning, moisture-wicking, odor-fighting, and comfort — all at a pretty reasonable price. They've got a good mix of most of materials (including merino wool) and they've earned a 4.6-star rating after more than 1,400 reviewers on Amazon.
One reviewer wrote: "These are GREAT socks. They fit well without strangling my feet. They are cushioned and very warm. We live in a cold climate at an elevation of 6800 ft., so have deep snow Oct-late Apr. My husband and I both tried several brands for warmth and comfort, and these top the charts!"
- Materials: 66% acrylic, 21% merino wool, 12% nylon, 1% spandex
- Available colors: denim, heather gray, khaki, gray, charcoal
- Available sizes: women's 4-9 — 9-12 (Shop men's sizes here)
2. The Best Value
Maybe you're looking for a bargain, or maybe you're the type of person who goes through socks very quickly. Either way, these Debra Weitzner socks come in a pack of six pairs for less than $25. Despite the price, however, their thermal capabilities have earned them a 4.5-star rating after more than 1,200 reviews. They're thick, double-reinforced, and use a combination of natural and synthetic materials that trap heat in so your feet stay extra warm.
One reviewer wrote: "Great quality, great value! Thick, soft, and warm! I am very picky when it comes to my socks and these are perfect for cold winter days either when just hanging around the house or to wear with my boots when taking my dogs out on a snowy day."
- Materials: 45% cotton, 38% merino wool, 10% polyester, 7% elastic
- Available colors: black, two-tone
- Available sizes: men's/women's 5-10 — 7-14
3. The Warmest Option
For those who need an extremely warm sock (or for people who are looking for a wool-free alternative), these Heat Holders socks are the way to go. They're seven times warmer than your basic cotton sock and have a Thermal Overall Grade rating of 2.34 (other thermal socks tend to fall somewhere around 0.89, according to the brand). While they aren't great with moisture, their synthetic materials are woven in a way that offers impressive insulation and unparalleled brushed softness.
One reviewer wrote: "Love these socks compared to any other 'warm' sock. Bought me a pair then had to buy some for my wife and daughter. We all love them and agree they are the warmest socks we have ever had. Finally socks that keep my feet warm in the winter while hunting."
- Materials: 91% acrylic, 5% nylon, 3% polyester, 1% elastane
- Available colors: 14 colors and patterns including black, charcoal, and indigo
- Available sizes: women's 5 — 9 (Shop men's sizes here)
4. A Fan-Favorite Wool Sock With A Lifetime Guarantee
Wool is known for its moisture-wicking properties and durable warmth, and these hiker socks from Darn Tough have the highest percentage of it out of all the socks on this list. They're made from 59% high-quality merino wool, so they balance your skin's temperature while keeping your feet dry all day long. They also have a mid-level cushion for comfort as well as seamless technology for a chafe-free, invisible feel that stands up to extreme friction. Best of all, it's backed by a lifetime warranty and an outstanding 4.8-star overall rating after more than 1,000 reviews.
One reviewer wrote: "Honestly ... these socks (so far) have outperformed all other brands I've tried. I'm very hard on socks, wearing them out in the heel in no time. I'm a hardcore hiker, and the socks are worn with hiking boots, water shoes, and everything in between. I've had these for 6 weeks now, and they show NO signs of wear. Not even pilling like some brands of socks I've tired."
- Materials: 59% merino wool, 39% nylon, 2% spandex
- Available colors: 8 colors including aqua heather, denim, and slate
- Available sizes: women's Small — Large (Shop men's sizes here)
5. The Best Tall Socks
If you're looking for an extra-tall sock for skiing and snowboarding (or just to keep your calves cozy), you'll want something thin enough that your boots still fit properly, warm enough to provide comfort despite the weather, moisture-wicking enough to counteract sweating, tall enough to prevent chafing, and cushioned enough to absorb shock. Luckily, these skiing socks from WEIERYA offer it all. They're a number-one best-seller with over 2,000 reviews because they're engineered for warmth, dryness, and an optimal fit.
One reviewer wrote: "Great, warm socks! I wore them skiing in Big Bear. My feet stayed warm the whole time! Bonus that it comes in a two pack! I let my husband wear the other pair. He loved them, too! Highly recommended!"
- Materials: 86.1% cotton, 12.2% nylon, 1.7% spandex
- Available colors: 10 colors including blue, gray, purple, and pink
- Available sizes: men's/women's Small — X-Large
6. The Best Patterns
Finally, you've got these warm thermal socks from Sunew. While they're made from a thick, plush synthetic fabric that keeps the warmth in, but they're especially great for people who love fun patterns. You can get them in designs like autumn leaves, red elk, holiday presents, paisley, plaid, and snowflakes — more than 30 options in total including two-packs.
One reviewer wrote: "These are SO soft, comfy and warm! They do run pretty big, which I like, and they are pretty thick, so wouldn’t be able to wear these with sneakers but would be great with boots. The pattern is cute and the interior is fuzzy and soft. No annoying seams or strands digging into your skin anywhere."
- Materials: 91% acrylic, 8% polyester, 1% spandex
- Available colors: More than 30 options including elk, fair isle, and red-and-black checkers
- Available sizes: men's/women's Medium — Large