I tested the sleeping bag last night, minimum: -6.7°C outside and -1.0°C inside the tent. Wearing thermals and a mircofleece I was just at the limit of having a comfortable night's sleep, but I am a light sleeper, so I think the lower temperature rating (-5°C) is accurate. The outer shell is also excellent at stopping condensation, and it is quite compressible, overall the sleeping bag is very good value for money, and good quality.