Many people with asthma find that humid weather makes their symptoms worse.

Small-scale research has looked into how humid weather affects a person’s lungs. The researchers tested airway resistance — a measure of how easy it is to breathe — in six people with asthma and six people without.

After experiencing hot, humid air (49°C and 75–80% humidity) for 4 minutes, people with asthma had a 112% increase in airway resistance as opposed to the healthy group that only had a 22% increase in airway resistance. People can prevent humidity-related asthma symptoms using a range of strategies, including taking medication, controlling indoor humidity levels, and avoiding exercising in humid conditions.