Down or synthetic? For most cold-weather camping, down is the winner based on its lightness, durability, and comfort.
As for the temperature rating, aim for at least zero degrees Fahrenheit. Minus ten would be even better. There’s not a huge difference in weight only four to six ounces. Buy a bag that’s rated for the lowest temperature you are likely to face. You might see colder weather but can always add clothes or bring a jacket into the sleeping bag.
So what sleeping bags? There are lots of quality gear manufacturers. When I went on my search for a bag my criteria were:
- A quality manufacturer
- I tend to sleep cold and wanted at least a rating to -15
- Legitimately sized for someone 6’4″ and 225 lbs
I bought a Western Mountaineering Big Horn Super MF rated to -25 with 9″ inches of loft from its 850-plus fill, and a breathable microfiber shell. Western Mountaineering offered an option to have the bag overfilled with an additional 4 oz of down. The bag weighs three pounds, 11 ounces. It was pricey but my last cold weather down sleeping bag lasted nearly 30 years. I expect this one to last for my remaining winter camping career. Since I bought this bag it has been discontinued/merged with the Western Mountaineering Puma series.
Get two sleeping pads: a self-inflating pad as well as a closed-cell foam pad as shown below. This setup really makes a difference in cold-weather camping.
Finally, keep in mind that sleeping bags alone don’t ensure a warm sleep. Wear long underwear and a hat. Give yourself the option of pulling on gloves and extra socks if needed. You can also pull your down parka inside your bag and lay it over you as an extra blanket if you get chilled. Before bedtime a bit of exercise and a bite of chocolate will give extra heat-generating energy.