Thursday 29 January, 2026 | Read Time: 6 mins
Beth Wright
They’ve seemingly appeared out of nowhere. These invisible storms that leave people with asthma, undiagnosed asthma and even some with hay fever (allergic rhinitis), struggling for air with very little warning.
What Is Thunderstorm Asthma?
Thunderstorm-triggered asthma (TA) is a rare but potentially deadly phenomenon where a perfect storm of pollen, weather, and human susceptibility triggers severe asthma symptoms and acute asthma attacks in a matter of minutes [1].
While uncommon, TA events have revealed vulnerabilities in our health systems, raised questions about climate change.
Typically, these episodes happen during pollen season, when thunderstorms stir up and fragment pollen grains, releasing respirable particles that can penetrate deep into the lungs [1].
For those sensitised to allergens (link) this can provoke sudden and severe asthma attacks, even in individuals without a prior history of asthma. Symptoms are related to both hay fever and asthma, they include:
- Sudden breathlessness
- Chest tightness
- Wheezing
- Cough
- Sneezing
- Itchy, watery eyes and/or runny nose
- Skin irritation
Just how common is thunderstorm asthma?
In the past 30 years, it is estimated that epidemic thunderstorm asthma events (ETSA) have occurred over 26 times in locations around the world [2]. For instance, a TA outbreak in Italy is thought to have been triggered by olive tree pollen in 2010[3].
One of TAs deadliest occurrences was recorded in November of 2016 in Melbourne, Australia. The figures were disproportionately large, stretching health services to maximum capacity:
- Over 3,400 people sought emergency care
- 10 deaths were recorded
- 10-fold increase in asthma admissions
- 35 admitted to intensive care
What did those most affected have in common?
- Allergic rhinitis
- Ryegrass pollen sensitization
- Pre-existing asthma, particularly poorly controlled
- No prior history of asthma in some cases
The scale of the disaster highlighted both the unexpected reach of TA and the importance of identifying high-risk populations before storms hit.
What makes TA such a huge problem?
Why has this seemingly innocent combination of pollen and spring thunderstorms become such a huge issue?
There are many contributing factors - not the least of which includes the rapidly rising rates of asthma and respiratory conditions.
Despite the increasing ability to treat and manage these respiratory conditions, the current capacity of health services to manage asthma spikes are still limited [4]. Not to mention that people may not even know they are at risk of these attacks due to lack of diagnoses, or poorly managed conditions.
So, one of the deadliest aspect of TA may be its ability to rapidly overwhelm emergency services, pharmacies, and healthcare infrastructure.
Healthcare systems, researchers, and communities must adapt quickly, combining environmental monitoring, patient education, and rapid response strategies to prevent future tragedies [4]
The effect of Climate Change on the Future of TA
It’s a complex combination that can turn deadly.
Many researchers project that climate change, especially in combination with rising rates of asthma, air pollution and urbanisation, will likely increase the frequency of thunderstorm-triggered asthma events.
You know it, I know it - the effects of climate change are not new information.
Climate change = Longer pollen seasons, extreme rainfall, and stronger thunderstorms
All of which contribute to higher risk.
What we know now - The Mechanisms Behind Thunderstorm Asthma
Researchers believe pollens (especially grass pollens) to be the main allergen involved in TA outbreaks [5]. Although, there are many hundreds of contributing factors resulting in the potency of TA. These include but are not limited to:
- Agricultural activity and urban air pollution can further exacerbate pollen levels or airway sensitivity.
- High humidity and rainfall cause pollen grains to swell and rupture/burst, releasing microscopic allergenic particles which can penetrate deeper into our lungs than typical pollen.
- Thunderstorm outflows sweep pollen and other pollutant particles to ground level, creating concentrated allergen clouds - particularly in cities [4]. For instance, ruptured grass pollen grains increased by 250% in Burwood, Victoria following the thunderstorm outflow [3].
- Rapid temperature changes, wind gusts, and sudden rainfall amplify the effect - and unpredictable weather is becoming more commonplace due to factors such as urbanisation and climate change.
Is pollen the only culprit?
TA is hugely complex, and pollen is not the only culprit responsible for these outbreaks. For instance, fungal spores have also been implicated [6].
As usual in the science world however, there are discrepancies:
- Not all thunderstorms trigger thunderstorm asthma, even on days with high pollen counts.
- Other weather factors are involved in thunderstorm asthma.
- It is not only people with pollen allergy who may be affected by thunderstorm asthma.
- Fungal spores can also affect some people with asthma and other respiratory diseases during a thunderstorm
How do you protect against thunderstorm asthma?
There are many systems that can be improved to protect those most vulnerable to TA:
- Early warning systems such as predictive alerts based on pollen counts, weather forecasts, and population risk data.
- Public health campaigns that aim to educate patients about asthma, adherence and proper use of medications, as well as controlling seasonal hayfever.
- Clinical interventions for high-risk individuals such as allergen immunotherapy.
- Learn how to support family and friends by understanding asthma first aid such as the 4 4 4 rule.
What can you do to help protect yourself and our community?
There is no single way to protect our community.
TA storms are unpredictable and affect individuals differently depending on many individual factors. These may include individual symptom severity, concentration and length of pollen exposure, geographic location and healthcare service access. Other recommendations include:
- For those with allergic rhinitis, consider staying inside just before, during and after thunderstorms, and on high pollen days.
- Regularly seeing your doctor to make sure that your allergic rhinitis is well treated [3].
- If you experience symptoms of asthma such as chest tightness, wheeze, shortness of breath or cough, see your doctor for a plan to diagnose/manage asthma or other respiratory conditions.
- Identifying susceptible patients - those with allergic rhinitis, pollen sensitivities, or undiagnosed asthma - is a critical part of prevention [7].
- If you are already prescribed a preventer medication, it is essential to check your technique as up to 94% of patients do not use their inhaler device correctly. Always ask your doctor if you are unsure.
The Bottom Line
Thunderstorm asthma may be rare, but its impact is profound.
By understanding the complex interaction between allergens, weather, and human susceptibility, we can break through the clouds of uncertainty and develop strategies that save lives.
TA reminds us that sometimes, the most dangerous storms aren’t visible - and preparing for them requires vigilance, science, and community awareness.
What’s next?
While we can’t stop thunderstorms, pollen, and global warming is still going strong, advances in epidemiology, meteorology, and allergology are essential for helping our most vulnerable communities prepare.
It goes without saying that respiratory disease diagnosis and management is vital to combat TA.
This is where companies such as Diag-Nose come into play.
With devices such as ABEL microsampler, we are making moves to improve our capacity to diagnose patients, with RhinoMap promoting more efficent diagnosis, patient-treatment matching and moderating results for the best outcomes.
References
- D'Amato, G., Annesi-Maesano, I., Urrutia-Pereira, M. et al (2021). Thunderstorm allergy and asthma: state of the art. Multidisciplinary respiratory medicine, 16(1), 806. https://doi.org/10.4081/mrm.2021.806
- Price, D., Hughes, K. M., Dona, D. W., Taylor, P. E., Morton, D. A. V., Stevanovic, S., Thien, F., Choi, J., Torre, P., & Suphioglu, C. (2023). The perfect storm: temporal analysis of air during the world's most deadly epidemic thunderstorm asthma (ETSA) event in Melbourne. Therapeutic advances in respiratory disease, 17, 17534666231186726. https://doi.org/10.1177/17534666231186726
- Kevat A. (2020). Thunderstorm Asthma: Looking Back and Looking Forward. Journal of asthma and allergy, 13, 293–299. https://doi.org/10.2147/JAA.S265697
- Andrew E, Nehme Z, Bernard S, Abramson M J, Newbigin E, Piper B et al. Stormy weather: a retrospective analysis of demand for emergency medical services during epidemic thunderstorm asthma BMJ 2017; 359 :j5636 doi:10.1136/bmj.j5636
- Harun, N. S., Lachapelle, P., & Douglass, J. (2019). Thunderstorm-triggered asthma: what we know so far. Journal of asthma and allergy, 12, 101–108. https://doi.org/10.2147/JAA.S175155
- Pulimood T, Corden J, Bryden C, Sharples L, Nasser SM. Epidemic asthma and the role of the fungal mold Alternaria alternate. J Allergy Clin Immunol. 2007;120:610–617. doi: 10.1016/j.jaci.2007.04.045
- Price, D., Hughes, K. M., Thien, F., & Suphioglu, C. (2021). Epidemic Thunderstorm Asthma: Lessons Learned from the Storm Down-Under. The journal of allergy and clinical immunology. In practice, 9(4), 1510–1515. https://doi.org/10.1016/j.jaip.2020.10.022