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Best Sleep Sacks for Winter
Updated on
November 2, 2023

Best Sleep Sacks for Winter

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Best Sleep Sacks for Winter.
Best Sleep Sacks for Winter

Just like Goldilocks, trying to keep your baby’s temperature just right while they sleep—not too hot and not too cold—can be a bit of a head-scratcher, especially if you live in a place where winter packs a punch. And since loose blankets in the crib are a definite no-go, you’ll need something not only warm but safe as well.

Enter sleep sacks designed specifically for cooler sleeping temperatures: your new winter BFF. We’re taking you through what to look for, how to dress your baby for sleep when it’s chilly outside and the best sleep sacks for winter.

What Is a Sleep Sack?

A sleep sack is like a mini sleeping bag for your baby or toddler. Also called a wearable blanket, a sleep sack helps to keep your baby warm in their crib without using loose blankets. Most sleep sacks feature zippers or snaps for easy on/off and quick diaper changes.

Why use a sleep sack? Because your baby will likely get chilly overnight, especially if you live in a cooler climate, but putting things like blankets or quilts in the crib isn’t safe. (Check the American Academy of Pediatrics safe sleep guidelines for a full breakdown of the do’s and don’ts of safe baby sleep.)

Sleep sacks are the perfect answer to keeping your baby warm and safe throughout the night.

How Should a Sleep Sack Fit?

Be sure the sleep sack you choose is sized correctly for your baby. Test out the collar and pull it up to be sure it doesn’t cover your baby’s nose or mouth while they are laying on their back. Be sure the arm and neck openings aren’t too big. (Extra material below baby’s feet is fine.) And be sure there’s enough space in the hip area for them to move their hips comfortably to ensure proper hip development.

How Should I Dress Baby for Sleep?

The key to dressing a baby for sleep is to avoid any extremes—you never want your baby to be too hot or too cold. An easy way to tell is to touch their ears or their neck. If their ears are red or hot and their neck is sweaty, your baby is likely too warm. If they’re feeling cold, it’s probably time to add a layer.

Since sleep sacks designed for cooler temperatures are thick and warm, you usually only need one layer underneath, like a long-sleeve footie.

What Is TOG?

TOG is a term you’ll see mentioned in many sleep sack descriptions, especially those designed for cooler temps. It stands for Thermal Overall Grade, which indicates how much heat the fabric retains.

Sleep sacks with a higher TOG are more heavily insulated and meant for cooler temperatures, while lower TOG sleep sacks are lighter weight and better suited for warmer climates.

Many sleep sack brands have TOG rating charts to help you figure out which one is right for your baby’s sleeping environment.

What Is the Best Cold Weather Sleep Sack?

When choosing the best winter sleep sack for your baby, keep these things in mind:

  • Nursery temperature. How cool does your baby’s sleeping space get overnight? (The recommended temperature is between 68 to 72 degrees Fahrenheit or 20 to 22 degrees Celsius.) The cooler your nursery, the higher TOG sleep sack you’ll need.
  • Your baby’s temp. Does your baby tend to run hot or cool? Your little one’s internal heater will also affect choosing the best winter sleep sack for them.
  • Budget. Winter sleep sacks can get pricey. If you want to be able to use yours for as long as possible, invest in one that works from the early months through toddlerhood.

How We Chose Our Best Sleep Sacks for Winter

We asked thousands of real Babylist families about the baby products they love the most, then took the top products they shared with us and added our own research and insight to tell you about the best sleep sacks for winter.

Softest Sleep Sack for Winter

What Our Experts Say

If softness is what you’re looking for in a sleep sack, look no further, because Kyte Baby is where it’s at. This sleep bag is made from bamboo fabric and is about as comfy as they come. It has a double zipper for easy diaper changes and comes in a range of beautiful, on-trend colors.

What’s Worth Considering

This sleep bag is machine washable but you’ll have to skip the dryer and hang it up instead.

Best Affordable Winter Sleep Sack

What Our Experts Say

Sleep sacks for winter run on the pricier side, but not this one from Halo. It’s made from soft, warm microfleece and costs about half of many of the other options on our best-of list. It holds up well in the wash (and the dryer) and is available in lots of different sizes and colors.

What’s Worth Considering

This sleep sack has an inverted zipper, which we think isn’t as easy as the double zipper option. It’s also one of the lighter-weight winter sleep sacks on our list at a 1.0 TOG, so it’s not ideal for chillier sleeping spaces.

Best Winter Sleep Sack for Cold Temperatures

What Our Experts Say

An all-time favorite of a few Babylist team member parents, this jersey sleeping bag features everything there is to love about a winter sleep sack. It’s ultra-warm (2.5 TOG, to be exact), super soft and is made from 95% organic cotton with a hint of stretch. It’s also on the slimmer side, making it a good first sleep sack to transition to right after the swaddle. Babylist users also rave about how well it holds up wash after wash.

What’s Worth Considering

Also worth checking out: ergoPouch’s Sleep Suit Bags. They convert from a sleeping bag to a sleep suit and are ideal for walking toddlers and preschoolers.

Best Winter Sleep Sack with Style

What Our Experts Say

These sleep bags from Loulou Lollipop are just as stylish as they are functional. We love how warm and soft they are.

What’s Worth Considering

These sleep sacks are also air dry only, so factor that into your laundry time.

Best All-Season Sleep Sack

What Our Experts Say

If you’re the outdoorsy type, you likely already know how well wool keeps you cool and dry when it’s warm and nice and cozy when it’s not. The same idea holds true for this all-seasons sleep sack. It’s made from breathable Merino wool and naturally regulates your baby’s temperature in any environment. (The outer layer is made from organic cotton so it’s not itchy at all.) We also love that it’s not thick or bulky and that it features shoulder snaps and a two-way side zipper for easy dressing.

What’s Worth Considering

This sleep bag doesn’t come cheap. However, since it will last you from two months through about two years old and can be used all year, you’re getting your money’s worth.

Best Swaddle Transition Winter Sleep Sack

What Our Experts Say

Making the switch from a snug, secure swaddle to the freedoms of an unrestrictive sleep sack can be tricky for some babies. If you’re making that change during the winter months, this is our favorite transitional sleep sack to get the job done. It’s a 2.5 TOG, so it’s nice and warm, and it features zip-off wings so you can easily let those arms free when your little one is ready.

What’s Worth Considering

The zippers on the wings can be a little tricky to get on and off, but since you’re not doing it on the regular, it’s not a very big deal.

Best Winter Sleep Sack for Infants Through Toddlers

What Our Experts Say

This sleep sack goes the distance. Usable from about eight pounds all the way through to two years old, it’s the only one you’ll need from the newborn days through the toddler years. The material is a mix of viscose, bamboo and organic cotton so it’s supremely soft. There’s even a belt loop for straps if you want to use it in your stroller.

What’s Worth Considering

The lower portion of this sleep sack is quite wide and very long. (Which is great for an older baby but a bit overwhelming if you’re using it on a younger one.) We recommend using the bottom snaps to fold up the fabric and adjust the length to make it more suitable for a smaller, younger baby.

Most Comfortable Sleep Sack for Winter

What Our Experts Say

This duvet-style sleep sack is perfectly pint-sized and ideal for chilly nights. The down-like material is fluffy, soft and warm and feels just like your own favorite duvet, just made safe for little ones. There are top snaps plus a zipper for easy on and off.

What’s Worth Considering

Need even more warmth? There’s also an option with sleeves.

Best Winter Sleep Sack That’s Easy to Put On

What Our Experts Say

Getting a squirmy, wriggly baby into a sleep sack can prove quite the challenge, especially as toddlerhood looms. This sleep sack has a patented shoulder strap design that makes getting your little one in (and out) fast and painless. The quilted material is warm and cozy, and the price is much more affordable than many other higher TOG sleep bags.

What’s Worth Considering

One more differentiator here: the zipper. It’s sturdy and thick, so it’s more durable and takes less effort to zip up and down when compared to many other sleep sacks. (It’s not too bulky though, don’t worry.)

Babylist Team

This information is provided for educational and entertainment purposes only. We do not accept any responsibility for any liability, loss or risk, personal or otherwise, incurred as a consequence, directly or indirectly, from any information or advice contained here. Babylist may earn compensation from affiliate links in this content. Learn more about how we write Babylist content and review products, as well as the Babylist Health Advisory Board.