Lately I've been having chest pain when it gets real cold. Why is this?

Chest pain. Cold can trigger angina or cardiac chest pain. See your doctor asap!
Chest Pain/when cold. With your new onset of getting chest pain when it gets real cold, I will advice you to consult your family doctor as it may be a signal that you have heart disease. Cold air makes the arteries constrict and raise your blood pressure. With someone with undiagnosed heart condition, simply breathing in cold air can cause chest pain. So I will suggest you see your doc asap.
See below. Chest pain in the cold is very woorisome for angina. Cold causes constriction of the coronary arteries and if there is underlyng atherosclerosis, chest pain/angina results. See your doctor asap.