Weather that’s too humid or not humid enough can make it harder to breathe when you have chronic obstructive pulmonary disease (COPD), a lung disease that gets worse over time. Changes in humidity and temperature can trigger a flare-up. Symptoms that may get worse include coughing, wheezing, shortness of breath, and tightness in your chest. Cold weather can bring low humidity, which poses problems when you have COPD. Covering your nose and mouth when you're out can help.