Search results

Thunderstorm asthma is when certain thunderstorms trigger sudden and potentially severe asthma symptoms. It occurs when strong winds, rain and high pollen levels combine. During these storms, pollen grains (especially ryegrass pollen) can break into very small particles that are inhaled deep into the lungs, triggering severe asthma symptoms. 

You may be at risk of thunderstorm asthma if you:

• are allergic to grass or ryegrass pollen
• have springtime hay fever (allergic rhinitis)
• have asthma (especially if it is poorly controlled)
• are not using a preventer inhaler as prescribed
• have ever had asthma symptoms, even if you don’t currently have an asthma diagnosis.

To reduce risk, the National Asthma Council recommends:

• seeing your doctor for an asthma review
• using preventer medication consistently during the pollen season
• ensuring you have an up‑to‑date written asthma action plan
• staying up to date with pollen counts and weather forecasts during spring and early summer
• staying indoors before and during thunderstorms on high‑pollen days
• carrying a reliever inhaler at all times.

Learn more:

Thunderstorm asthma fact sheet