Skip to content

Is a 20 Degree Sleeping Bag Too Hot For Summer?

It’s hard to enjoy a summer camping trip with a sleeping bag that’s too warm. Nobody wants to wake up drenched in sweat without any way to cool off. What’s the best sleeping bag temperature rating for the summer?

Is a 20 Degree sleeping bag too hot for summer? A 20 degree sleeping bag will be too hot in the summer. You can unzip the sides and use it as a quilt, but there are better options for hot weather. I recommend purchasing a 40° degree bag and using layers and a bag liner on chilly nights.

Picking out a summer sleeping bag doesn’t have to be difficult. You don’t even have to spend a lot of money to get a warm weather bag. Continue reading to learn how to choose and get the most out of your summer sleeping bag.

A 20° Sleeping Bag is Too Hot For Summer

I carried a 20 degree Marmot sleeping bag throughout most of my college years. It was a great sleeping bag in the winter, but boy was it hot in the summer. You’ll be drenched in sweat the minute the sun comes up.

In all my years of camping I can’t remember anyone saying they were so hot they couldn’t sleep, but there are better options for 3-Season use. You might be sweaty and have to adjust your zipper, but you can usually find a way to cool off a bit.

Look for a sleeping bag with a full length zipper so you can get some ventilation in your bag. Unzip the side and stick an arm/leg out to cool off a bit. You can also use it as a quilt by completely unzipping the bag. This isn’t a great solution, but it can get you by on a hot night.

Check out my post on dealing with a sleeping bag that’s too warm.

If you can’t find a way to cool off it’s probably so hot that you’ll be uncomfortable regardless of the bag. For 3-Season use you’re better off with a sleeping bag with a higher temperature rating.

A 40 Degree Sleeping Bag is Perfect For Summer

A 40 degree bag is perfect for the majority of people in the summer. Women and cold sleepers might want to consider a 30 degree bag or liner. That’s the perfect temperature range for 3-Season use.

I really like my Kelty Cosmic 40 Degree Down Sleeping bag. It’s really light and compact, but it wasn’t cheap. A cheap $10 Walmart Ozark Trail Sleeping bag is all you really need on most summer nights. It’ll be a little heavy for backpacking, but it’s not bad with a compression stuff sack (my favorite).

It might be a little bit cold on cooler nights, but you can always wear a few extra baselayers. If you do a lot of early spring, late fall camping you should seriously consider picking up a sleeping bag liner.

Even a cheap Coleman fleece sleeping bag liner will add 12° F of warmth to your bag. Combined with well thought out base layers you can get an extra 20° from a bag.

A Sleeping Bag Liner Adds Versatility To Your Bag

If you’re worried about not having a warm enough sleeping bag you should seriously consider getting a liner. I have a Sea to Summit Thermolite Reactor liner that adds 25 degrees to my bag.

It was expensive, but it adds a ton of versatility to my sleeping bag. With my liner, I can use a 40° bag in cold weather. I would go with a 0° bag for winter but it has really saved me from some cold spring/fall nights.

I’ve been known to ditch my sleeping bag and just use the liner on warm summer nights. On 50° nights you should be comfortable with just the Sea to Summit Liner.

On those ridiculously hot nights you’ll wish you had a liner. You don’t want to get all that sweat and grime on your sleeping bag. It’s so much easier to wash a liner than the actual sleeping bag.