Hi Christine,   Absolutely, extreme weather, as Tom says, can be a trigger for asthma! High heat, humidity, and cold weather are all known triggers in sensitive people. High heat and humidity interact with ground level ozone to create very poor air quality. Dry, high heat can also increase the amount of pollen in the air during certain times of the year. Hot, humid weather can increase the number of mold spores in the air. And cold air tends to be dry, which dries out the airways and makes them more sensitive.   One of the latest studies suggests that severe thunderstorms are another form of extreme weather that can trigger asthma symptoms.   On the other hand, people with COPD will also be sensitive to poor air quality, so your best bet is to see your doctor to be sure.   Best, Kathi