When sleeping in the great outdoors, you are at the mercy of mother nature and whatever temperature she feels like dealing out. In my 15 years of camping in various conditions, I can confidently say that there are certain characteristics to look for in a sleeping bag to make the one you buy work comfortably for most scenarios. Many sites go into the nitty-gritty, but these recommendations are to help zero in on characteristics you want in your bag.
Sleeping Bag Temperature Rating
A 3 season bag is likely going to be the most versatile and comfortable choice. A three-season will usually run between 15-30 degrees. I generally don’t do a lot of early spring or late fall, known in Minnesota as winter, camping these days, so I don’t need a zero degree bag. If you are reaching for something more in the range of 30 degrees or warmer, know that the expectation is that you are camping in reliably warm weather. If you know that you run hot or cold, take this into account when selecting a bag.
NOTE: There is no standardized rating system for sleeping bag temperature ratings. Each company has its own independent standards and rating differences can mean different things to different companies. Transparency has gotten better for this in recent years but it’s a thing to be aware of.
Sleeping Bag Shapes
Rectangular: This is the old standard shaped sleeping bag. They have lots of room but on cooler nights they don’t keep you as warm. These are good for car camping, sleepovers, or in the backyard, but not much more.
Semi Rectangular: This is a cross between the two ends of the spectrum. I move around a lot in my sleep so I can’t comfortably sleep in a mummy bag. I appreciate my spoon bag which is further accommodation for this but essentially falls in this category.
Mummy: It’s usually tapered at the bottom and is snugger around your body. This typically eliminates dead space your body needs to heat so it’s usually warmer.
Sleeping Bag Insulation
Unless you have a real fondness for down, buy synthetic. Synthetic insulation is much better than it used to be, and it is more cooperative. Down is fussy, it does not like to get wet, it does not like to be compressed in my experience, and I feel like ethically sourced down is an oxymoron. It’s usually way more pricey too, plus I am allergic, so I have some built in bias here. Just make sure it’s made without cotton. If there’s cotton in it, it’s good for kids in the backyard or sleepovers.
Sleeping Bag Features
I feel like they have gone a bit overboard with features, but the ones to be aware of are zipper length and material and the hood. I like to unzip my bad most of the way and use it more like a blanket if it’s hot. If you are looking to trim weight, plastic zippers are lighter than metal ones, and they don’t get as cold. If the bag doesn’t have a hood, I don’t even want it. I like to be able to cinch the hood down too. It’s awesome for nights that are a bit colder. There are tons of selling point features, but it’s a sleeping bag, not a multitool. I wouldn’t buy one bag over another because of a pocket or something
Weight for Backpacking
With all this information in mind, if you’re looking at one for backpacking, make sure the one you’re buying has a weight you find acceptable and a packed-down size you can work with. My bag of choice takes up a bit more space than your typical backpacking bag, but I don’t mind. Some come with a stuff sack, which is convenient.
Final Advice About Storage
If you’re not using the bag out camping or on the trail, find a dry spot to store it UNPACKED. Don’t store your bags stuffed, or it is likely to compress the insulation. This turned one of my 25-degree bags into more like a 45-degree bag in two years. This is also more likely to dry out completely, so it’s not accidentally packed away damp and turns into a moldy nasty piece of garbage.