Asthma can be hard enough to cope with when the weather is mild, but certain severe weather conditions can trigger symptoms to a larger degree.
Cold, dry air can trigger bronchoconstriction, which is the narrowing of the airway. This is particularly symptomatic for those who suffer from exercise-induced asthma. Warm, humid air is much less likely to trigger symptoms.
Heat and humidity CAN trigger symptoms by causing mold and dust mites to thrive for those who suffer from aggravating allergic asthma, however. Air pollution is also a concern as heat and humidity rises. Even thunderstorms can trigger asthma symptoms. Rainfall breaks up pollen grains and then the wind from the storm stirs them up and makes it easier to inhale.