If there's one thing you want when you're camping in cold weather, it's a warm, reliable sleeping bag. But the tricky part is that it needs to be lightweight and compact too — especially if you're backpacking.The best cold weather sleeping bags are typically made with warm insulation and high-denier fabrics. They also have tough zippers that won't snag when you zip yourself in and out.
The best sleeping bags to keep you warm are typically filled with real goose down for insulation, though there are some great synthetic versions too. Just keep in mind that real down needs to be treated with a water-resistant coating or it will cease to be effective when damp. As you shop, you'll come across a specification called fill power, which essentially indicates how fluffy and compressible the fill is — a higher fill power means it can trap more warm air, thus requiring less fill and reducing the overall weight of the bag.
Another thing to consider is the sleeping bag's temperature rating — for cold weather, you'll typically want something between 0 and 20 degrees Fahrenheit. Most sleeping bags in the U.S. are rated in degrees Fahrenheit,though if you ever see a "0 degree" bag that's considerably less expensive, be sure to check that it isn't deceptively rated in Celsius (which is the equivalent of 32 degrees Fahrenheit).
The outer material that holds the insulation and makes direct contact with your skin is important, too. The shell and lining should be made of a strong, durable material that's resistant to snagging. Fabrics like ripstop nylon or nylon taffeta are generally best.Also take a look at the fabric's denier count, which measures the thickness of the threads. A high denier count typically indicates a thicker, more durable fabric — but it can also be heavier.
Finally, a backpacking sleeping bag will ideally clock in under 3 pounds, but car camping usually gives you more flexibility to choose a heavier bag.