Epidemic Thunderstorm Asthma

Melbourne experienced the world’s largest epidemic thunderstorm asthma event on 21 November 2016, with thousands of people developing breathing difficulties in a very short period of time. Though epidemic thunderstorm asthma events are uncommon and don’t occur every year, when they do it is usually during grass pollen season from 1 October to 31 December.

What is thunderstorm asthma?

During grass pollen season people may notice an increase in asthma and hayfever. This season also increases the likelihood of thunderstorm asthma.

Thunderstorm asthma is thought to be triggered by a unique combination of high grass pollen counts and a certain type of thunderstorm. For people who have asthma or hayfever this can cause severe asthma symptoms, making it difficult to breathe. When a large number of people develop asthma symptoms over a short period of time, this is known as epidemic thunderstorm asthma.  

Learn more about asthma and hayfever.   

Who is at risk?

Thunderstorm asthma can affect those with asthma or hayfever - especially people who experience wheezing or coughing with their hayfever. That’s why it’s important for people with asthma or hayfever to know about thunderstorm asthma and what they can do to help protect themselves during grass pollen season. Even if you don't think you have asthma or hayfever, don't ignore symptoms like wheezing or shortness of breath - check with your GP.  

Epidemic thunderstorm asthma forecasting

The Department of Health and Human Services has collaborated with the Bureau of Meteorology and other research organisations to develop an epidemic thunderstorm asthma forecasting system. This enhanced system will commence delivering daily epidemic thunderstorm asthma forecasts on 1 October and will continue to 31 December, which is the typical Victorian grass pollen season.

Download the VicEmergency app and set up a 'watch zone' for your location to receive advice and warnings about potential epidemic thunderstorm asthma events during the grass pollen season. The department will also operate a subscription service for the distribution of epidemic thunderstorm asthma forecasts on forecasted high risk days only. To subscribe please visit www2.health.vic.gov.au/newsletters. We encourage you to subscribe to receive alerts to ensure you are informed and prepared this grass pollen season.

The department recently launched an epidemic thunderstorm asthma campaign to help you protect yourself and those in your care. You can access a range of information and resources at www.betterhealth.vic.gov.au/campaigns/thunderstorm-asthma.