Winter Sleeping Bags
Winter camping is entirely fun when done well with proper equipment, and a fully miserable experience when your equipment fails. So, if you plan to camp in the snow and cold weather, purchase or rent the proper equipment. Many of the rules for picking out sleeping bags get thrown out the window when choosing a bag for winter camping. Weight, is no longer the primary concern. Instead, warmth and space are the two primary factors you should consider.
Temperature: A sleeping bag should have a much lower rating than the lowest temperature you expect (unless of course 40 below is the lowest temp you plan to encounter). If the nighttime low is 10 ° Farenheit, you will want at least a 0 ° bag. Generally speaking, a 0° bag or warmer will be necessary for any winter camping trip.
Size: Most of the time, a sleeping bag should fit snuggly around your body with some room to roll around. This is both because of weight and warmth. However, for winter camping, buy a sleeping bag a bit bigger. Your camera, iPod, jacket, and feet will all thank you. Anything that has batteries should be stored at the foot of your sleeping bag. Often, campers store clothes at the foot their bag as well. This keeps batteries from dying in the cold night air and keeps clothes (layers and socks specifically) from freezing.
Insulation: The debate between down and synthetic is one that will never be won for either side, but in snow camping, 650-700 fill down is the best insulation, as long as you can keep it dry. If you expect to be camping in cold, wet conditions (not specifically snow), consider a synthetic bag. It is important to realize that a 0° synthetic bag is enormous and does not pack down well, but it will retail some warmth if it gets wet. If you plan to be in the snow and sleeping in a tent with a floor, then take a zero degree or warmer down bag.
Now, go out and have some fun in the snow!