Feels like i'm breathing in a lot of cold air, dry throat, coughing, especially at night. what could be wrong?

Mouth Breathing : People who mouth breath at night when the air is cold and less humid often dehydrate their mouth and throat to the point of wakeing up and coughing. Also breathing cold air is irritating to the mucosa in the back of your throat. When you breath through your nose, the air is warmed before it hits your throat. If you can't clear your nasal passages, try sleeping with a surgical mask.