As temperatures start dropping, your body works harder to keep warm, putting strain on your heart and lungs. Low temperatures can cause the narrowing of blood vessels, which then restricts blood flow throughout the body, causing a loss of oxygen to the heart. To offset this, our lungs start working hard to help provide oxygen in the bloodstream so that your body has what it needs. This extra work on your lungs can aggravate common COPD symptoms such as shortness of breath and chronic coughing and wheezing.
Colder temperatures also generally mean drier air. Dry air conditions often irritate lungs due to the lack of moisture in the body's airways. This irritation can cause inflammation, which leads to more chronic coughing.