Spring brings higher grass pollen levels across NSW. Thunderstorm asthma in NSW can occur when high pollen levels combine with certain thunderstorm conditions. This can trigger asthma symptoms in susceptible people, including people with hay fever who have never been diagnosed with asthma.
This article explains who may be at risk, how to prepare before the higher-risk months, what to do when storms and high pollen are forecast, and when to seek medical or emergency help.
Key Takeaways
- Thunderstorm asthma is uncommon, but certain spring weather and pollen conditions may trigger symptoms in people with hay fever or asthma.
- Reviewing prescribed asthma management, keeping an action plan current and checking weather and pollen information can support preparation.
- Knowing when symptoms are worsening, and when to call 000, is an important part of being prepared.
What Is Thunderstorm Asthma and Why Does It Happen in Spring?
Thunderstorm asthma can occur when high grass pollen levels combine with certain thunderstorm conditions, exposing susceptible people to tiny airborne pollen particles that can trigger asthma symptoms.
Weather conditions associated with some thunderstorms can cause grass pollen particles to become smaller and easier to inhale, which may trigger asthma symptoms in susceptible people. These fragments can be breathed deeper into the airways. The exact mechanism is not fully understood, and not every thunderstorm creates these conditions.
NSW Health identifies October to December as the higher-risk period. The greatest documented risk is in southern NSW and the Riverina, although events have also been recorded in other inland areas.
Who Is at Risk of Thunderstorm Asthma?
People with grass pollen sensitivity, hay fever, or current or previous asthma may be at risk. Hay fever and asthma are different conditions, and most people with hay fever will not experience thunderstorm asthma.
Groups who may be affected include:
- People with spring hay fever, particularly those sensitive to grass pollen, even without diagnosed asthma
- People with current or previous asthma
- People who wheeze or cough during spring but have never been assessed
- People whose asthma is not well controlled
How Can You Prepare for Thunderstorm Asthma Before Spring?
Preparing early means reviewing your individual circumstances before the higher-risk months begin. Useful steps include:
- Review your asthma management. If you have asthma, discuss symptom control and your prescribed medicines with your GP.
- Check your Asthma Action Plan. Make sure your written plan is up to date and that you know how to follow it.
- Review your inhalers. Check that they are accessible and not expired, and ask about your technique. Use medicines only as prescribed.
- Raise hay fever and wheezing. If you get unexplained wheezing or chest tightness in spring, ask about assessment for possible asthma.
- Prepare your family. Parents can make sure school or childcare staff have their child’s current plan and access to prescribed medicines. Learn more about children’s healthcare at Branxton Healthcare.
Australian asthma guidelines recommend that asthma treatment plans are tailored to each person’s symptoms, risks and clinical situation. Many modern asthma treatment approaches include anti-inflammatory medicines where clinically appropriate. The right regimen differs between people, so do not start, stop or change medicines without medical advice.
If you experience wheezing during spring or are unsure whether your current asthma management suits the pollen season, a GP assessment for seasonal breathing symptoms can help review your symptoms and next steps.
What Should You Do When High Pollen Levels and Thunderstorms Are Forecast?
If you are at risk, check local weather forecasts and pollen information during spring. On days when high pollen and thunderstorms are expected:
- Stay indoors before and during the storm, especially during the gusty winds that can arrive before rain
- Keep windows and doors closed
- Set suitable air conditioning to recirculate indoor air
- Keep your prescribed reliever medicine within reach
- Follow your individual management plan
These steps may reduce exposure, but they cannot guarantee protection. For more information on NSW conditions and preparation, see NSW Health’s thunderstorm asthma advice.
What Are the Symptoms of Thunderstorm Asthma?
The main symptoms are wheezing, coughing, chest tightness and difficulty breathing. They can develop or worsen quickly in affected people.
Hay fever usually causes sneezing, a runny nose and itchy eyes. Symptoms in the chest and lower airways need more attention. Symptoms alone do not confirm thunderstorm asthma, so if you notice new, unfamiliar or recurring breathing symptoms outside an emergency, speak with a GP.
What Should You Do During an Asthma Attack?
If you have asthma, follow your written Asthma Action Plan and use your prescribed reliever as directed. If you do not have a plan, follow current asthma first aid guidance from the National Asthma Council Australia.
Call 000 immediately if someone has severe or rapidly worsening difficulty breathing, cannot speak comfortably, has blue lips, or gets little or no relief from their reliever. Continue asthma first aid while waiting for help.
First aid steps differ by age and inhaler type, so use the guidance that matches the person affected.
When Should You See a GP About Thunderstorm Asthma in Branxton?
Adults with recurring spring wheezing, hay fever with possible asthma symptoms, or existing asthma that needs review can discuss their history and current management with a GP. Where clinically appropriate, a GP may consider further assessment, testing or referral. You can read about what a spirometry test involves if breathing tests are discussed.
Adults and families in Branxton can contact Branxton Healthcare to arrange a GP appointment about seasonal breathing symptoms, asthma management or spring pollen preparation.
Frequently Asked Questions
Can thunderstorm asthma happen before it starts raining?
Yes. Susceptible people may be exposed to pollen particles during the gusty winds that can arrive ahead of some thunderstorms. This is why avoidance advice covers the period before rain begins.
Can I be at risk if I only have hay fever?
Yes. Seasonal hay fever linked to grass pollen sensitivity can be a risk factor even without diagnosed asthma. Speak with a GP if you have wheezing or other possible asthma symptoms.
Does treating hay fever prevent thunderstorm asthma?
Managing hay fever is important, but it has not been established as reliable protection against thunderstorm asthma. Discuss your individual risk and management with a health professional.
How can parents prepare children with asthma for spring?
Review your child’s asthma management and action plan with their clinician. Check that prescribed medicines are accessible, and give the school or childcare service the current plan.
References and Resources
NSW Health (2025) Thunderstorm asthma warning for NSW, NSW Health website, accessed 28 September 2026.
National Asthma Council Australia (2025) Time to prepare for thunderstorm asthma, National Asthma Council Australia website, accessed 28 September 2026.
NSW Health (2023) Be prepared for the asthma season, NSW Health website, accessed 28 September 2026.
SafeWork NSW (2026) Thunderstorm asthma, SafeWork NSW website, accessed 28 September 2026.