It seems that sleeping bag ratings have no consistency. Temperature ratings are still determined entirely by the manufacturers of the bags. My 3-pound Sierra Designs bag, for example, was rated to 20 degrees. Honestly, it never kept me as warm as my 17-ounce Western Mountaineering sleeping bag, which is only rated down to 40 degrees. Isn’t this a problem when you buy a bag? Maybe a 45-degree bag will keep you warmer than a 30-degree bag.
Consistent Sleeping Bag Ratings
No matter what temperature a bag is rated for, under any system of testing, it won’t necessarily keep you warm to that temperature. We can’t solve the problem of people having different metabolisms and bodies. A particular bag might be good for one person down to 20 degrees, while for another it is only good to 40 degrees. You generally can figure out if you are a cold or a warm sleeper, but that doesn’t help if you don’t know whether a bag is rated too high or too low.
You need to know that if a bag says 30 degrees it will keep you warmer than one that says 40 degrees. With that, even if you add or subtract 10 or 20 degrees for your personal tastes, you...