Weather conditions can cause asthma exacerbations in some patients. Both high or low temperatures and humidity can cause bronchoconstriction during physical activity. Thunderstorms can also result in asthma attacks in certain people.

Such people usually also have seasonal allergic rhinitis. Rain associated with thunderstorms results in rupturing of pollen grains and the production of more allergenic debris, which is then swept downwards by cold air currents to accumulate at ground level. This debris can then trigger an asthma exacerbation.

Patients who are prone to asthma attacks associated with pollen or mould allergies should be advised to stay indoors during thunderstorms.