Thunderstorm Asthma: Triggers and How to Stay Safe

On a warm November evening in 2016, Melbourne’s hospitals saw something never recorded before: a 672% spike in respiratory emergency presentations in just 30 hours, with 3,365 more people than usual rushing to emergency departments and 10 deaths linked to the event.

Most had one thing in common: spring hay fever and a sudden thunderstorm. Many had never been told they had asthma at all.

This rare but serious phenomenon is called thunderstorm asthma – and it’s a uniquely important issue for Australians, especially in spring and early summer. If you get hay fever, have asthma, or just find yourself “wheezing and sneezing” when the grass is high, understanding thunderstorm asthma could literally save your life.

In this post, we’ll walk through:

• What thunderstorm asthma actually is (in plain English)
• The key asthma triggers involved
• Who’s most at risk in Australia
• How to read weather and pollen warnings
• What your Asthma Action Plan should cover
• Practical steps to protect your respiratory health – and how telehealth in Australia (including our team at NextClinic) fits into your safety plan

By the end, you’ll know exactly what to do before, during, and after a stormy, high‑pollen day – so you can enjoy spring without constantly worrying about your lungs.

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What Is Thunderstorm Asthma?

Thunderstorm asthma is a type of asthma flare-up triggered when high levels of grass pollen in the air meet very specific thunderstorm conditions.

Here’s what happens:

1. On warm, windy spring days, grass pollen (especially ryegrass) fills the air.
2. A thunderstorm develops. Updrafts in the storm sweep pollen grains high into the clouds.
3. In the humid storm environment, the pollen grains absorb water and burst into thousands of tiny particles.
4. When the storm front (gusty winds) hits, those microscopic particles are blown back down to ground level.
5. Because they’re so small, they can bypass the nose and upper airways, reaching deep into the lungs and triggering sudden asthma symptoms.

When this happens to large numbers of people at once, we call it epidemic thunderstorm asthma – the kind of event Melbourne experienced in 2016.

You can get thunderstorm asthma:

• Even if you’ve never been diagnosed with asthma before
• Even if you “only” have spring hay fever
• Even if your asthma is usually mild

That’s why this topic matters to a broad Australian audience – not just people with a formal asthma diagnosis.

A Quick Look Back: The 2016 Melbourne Thunderstorm Asthma Event

On 21 November 2016, during peak grass pollen season, a line of thunderstorms crossed Melbourne and Geelong. Within 30 hours:

• Respiratory emergency presentations jumped 672%
• There were 3,365 more respiratory presentations than usual
• Asthma-related hospital admissions increased by around 10-fold
• 35 people were admitted to intensive care
• 10 deaths were linked to the event

Research later showed that:

• The vast majority of people affected had spring allergic rhinitis (hay fever) and strong allergy to ryegrass pollen.
• Many had no prior asthma diagnosis.
• Those with the worst outcomes generally had known asthma but weren’t using inhaled corticosteroid (ICS) preventers regularly.

For many Australians, this was the first time they’d heard the phrase “thunderstorm asthma” – and it changed the way we think about springtime storms and our lungs.

The Victorian Government has since set up a dedicated Epidemic Thunderstorm Asthma Program and statewide risk forecasts to help warn people when conditions are dangerous.

Why Does Thunderstorm Asthma Happen? The Triggers Explained

Understanding the asthma triggers behind thunderstorm asthma makes it easier to stay safe.

1. Grass Pollen (Especially Ryegrass)

In south‑eastern Australia (Victoria, southern NSW, ACT, parts of SA and Tasmania), spring and early summer bring very high levels of ryegrass pollen. This is the same pollen that causes classic hay fever: sneezing, itchy eyes, runny nose.

For people who are sensitised (allergic) to ryegrass pollen, breathing in tiny broken pollen particles deep into the lungs is a powerful trigger for asthma.

2. Specific Thunderstorm Conditions

Not every storm will cause thunderstorm asthma. The highest risk tends to be when:

• It’s spring or early summer, during peak grass pollen season
• It’s been hot and windy, stirring up lots of pollen
• A gusty thunderstorm rolls in, with fast-moving cool air
• Humidity rises quickly, causing pollen to rupture into tiny particles
• The storm’s outflow winds push those particles down to the breathing level

That’s when we get the “perfect storm” – a cloud of microscopic allergen particles at head height that can be inhaled deeply with each breath.

3. Underlying Asthma & Hay Fever

Thunderstorm asthma doesn’t strike totally at random. Your baseline respiratory health and existing sensitivities matter a lot:

• Poorly controlled asthma (especially without a preventer inhaler)
• Spring hay fever driven by grass pollen
• Previous hospitalisation or emergency visit for asthma
• No current Asthma Action Plan

These factors don’t cause the storm – but they make your lungs more vulnerable when one hits.

4. Climate and Environmental Changes

Emerging research suggests that longer pollen seasons and more frequent extreme weather events driven by climate change may increase the risk window for thunderstorm asthma over time.

That means staying on top of your respiratory health is becoming even more important for Australians.

Who Is Most at Risk in Australia?

Health authorities and researchers consistently highlight several key risk groups.

You’re considered at higher risk of thunderstorm asthma if:

• You have diagnosed asthma, especially if:
  • You don’t use an inhaled corticosteroid (ICS) preventer
  • You rely mostly on your blue/grey reliever
  • You’ve had asthma flare-ups in spring before
• You have hay fever in spring (allergic rhinitis) due to grass pollen – with or without known asthma
• You notice wheeze, shortness of breath, or night-time cough in spring but have never been checked for asthma
• You’ve ever had to go to hospital or ED for asthma
• You are an adult with both hay fever and asthma – data from 2016 shows adults were more likely to have serious outcomes than children

Some studies also found that people of South Asian and Southeast Asian backgrounds were disproportionately affected in the 2016 event, likely due to patterns of pollen allergy and under-treated asthma.

If you see yourself anywhere in that list, thunderstorm asthma is very relevant to you – even if you’ve never had a dramatic attack before.

Thunderstorm Asthma Symptoms: What To Watch For

Thunderstorm asthma symptoms are similar to other asthma flare-ups, but they can come on very suddenly during or just before a storm on a high‑pollen day.

Common symptoms include:

• Wheezing (a whistling sound when you breathe)
• Shortness of breath or trouble breathing
• Chest tightness or pain
• Persistent, irritating cough
• Feeling like you can’t get enough air, especially when talking or walking

Signs of a Severe Asthma Attack – Call 000 Immediately

Call triple zero (000) and ask for an ambulance if you or someone else:

• Has severe trouble breathing (gasping for air or unable to speak in full sentences)
• Is sucking in at the throat or ribs when breathing
• Has lips or face turning blue or grey
• Is becoming confused, drowsy or collapses
• Is not improving after following asthma first aid with reliever medication

In these situations, telehealth is not appropriate – you need emergency, in‑person care.

For less severe but still worrying symptoms, follow your Asthma Action Plan or standard Asthma First Aid steps, then seek urgent medical advice.

How to Know When Thunderstorm Asthma Risk Is High

You don’t need to guess. There are several Australian tools and forecasts you can use regularly in spring.

1. Check Thunderstorm Asthma Risk Forecasts (Especially in Victoria)

The Victorian Department of Health provides an Epidemic Thunderstorm Asthma Risk Forecast during grass pollen season (typically October–December). Risk levels (e.g. low, moderate, high, extreme) are available via:

• The VicEmergency website and app
• Daily updates from the Department of Health and partner organisations

Other states and territories may not have the same dedicated system, but severe thunderstorm warnings plus high pollen counts are still a red flag.

2. Monitor Pollen Counts and Hay Fever Forecasts

Useful resources include:

• Bureau of Meteorology (BOM) weather forecasts and thunderstorm warnings
• The Australian Pollen Allergen Partnership and city-specific pollen services (e.g. Melbourne Pollen)
• The AirRater app (available in several states/territories)
• The National Pollen Forecast (for daily grass pollen levels in some cities)

If you see high or extreme grass pollen + thunderstorms forecast, treat that day as a high‑risk thunderstorm asthma day, especially if you’re in a known hotspot like south‑eastern Australia.

3. Time of Day Matters

Thunderstorm asthma risk is often highest:

• In the gusty winds just before the storm hits
• Sometimes just after the initial change, when cool air rushes in and pollen particles are pushed down

That’s the time to be extra cautious about being outdoors.

Your Thunderstorm Asthma Safety Plan: Step-by-Step

You can’t control the weather, but you can take control of your respiratory health. Here’s a practical roadmap.

Step 1: Get Your Asthma and Hay Fever Under Control

Thunderstorm asthma is much less likely to be severe if your everyday asthma is well managed.

Current Australian guidelines recommend that all adults and adolescents with asthma use inhaled corticosteroid (ICS)-containing treatment, rather than relying on reliever alone.

That usually means:

• Taking your preventer inhaler every day as prescribed
• Using your reliever inhaler only as needed, not constantly
• Controlling hay fever with:
  • Regular intranasal corticosteroid sprays
  • Non-drowsy antihistamine tablets
  • Allergen avoidance strategies where practical

If you’re not sure your asthma is controlled, signs it may not be include:

• Using your blue/grey reliever more than two days per week (outside of pre‑exercise doses)
• Waking at night with coughing or wheezing
• Struggling with everyday activities due to breathlessness
• Recent hospital or emergency visits

This is where telehealth in Australia is a powerful tool. You don’t have to wait weeks for an appointment or sit in a busy waiting room during pollen season.

At NextClinic, our Australian-registered doctors can:

• Review your asthma symptoms and medication use
• Renew your preventer and reliever prescriptions online
• Help optimise your hay fever management (e.g. nasal sprays, antihistamines)
• Decide when you need in‑person lung function tests or a local respiratory specialist

You can learn more in our detailed post, “Asthma Check-Up via Telehealth”, on the NextClinic blog, where we break down how to refresh your Asthma Action Plan and scripts from home.

Step 2: Create or Update Your Written Asthma Action Plan

An Asthma Action Plan is a written set of personalised instructions from your doctor that tells you:

• Which medications to use day-to-day (your “green zone”)
• What to do when symptoms start to worsen (the “yellow zone”)
• Exactly what steps to take in an emergency (the “red zone”), including when to call 000

People with asthma who use a written action plan and have regular reviews have fewer hospital visits and days off work or school.

During a telehealth or in‑person consult, your doctor can:

• Confirm your current medications and doses
• Note your usual triggers (e.g. grass pollen, dust, viral infections, smoke)
• Write down specific steps to follow on forecast high-risk thunderstorm asthma days – for example:
  • “Use your preventer regularly and carry your reliever at all times”
  • “Avoid being outdoors before and during storms”
  • “Increase certain medications if instructed”

If you don’t have an action plan yet, consider making that your first priority after reading this article. It’s one of the simplest, most powerful tools for protecting your lungs.

Our doctors at NextClinic can help create or update a written Asthma Action Plan via telehealth, then email it to you so you can share it with family, your child’s school, or your workplace.

Step 3: Know Your Forecast Routine During Pollen Season

Make it a daily habit in spring and early summer to:

1. Check the weather forecast for thunderstorms (via BOM or your usual weather app).
2. Check pollen levels or thunderstorm asthma risk (via state or local pollen services, AirRater, or VicEmergency if you’re in Victoria).
3. If the day looks high-risk (storm + high pollen):
   • Keep your reliever inhaler and spacer with you at all times.
   • Make sure you’ve taken your preventer correctly.
   • Adjust your plans to avoid being outdoors during the gusty wind change.

This can be as simple as adding a “Pollen & Storm” check to your morning coffee routine.

Step 4: What To Do on a High-Risk Thunderstorm Day

On a day when grass pollen is high and thunderstorms are predicted:

If you’re in a risk group (asthma or hay fever):

• Stay indoors as much as possible, especially:
  • Just before and during thunderstorms
  • When it’s windy and dust/pollen is visibly blowing around
• Close windows and doors at home, work, and in the car
• Set your air conditioner to recirculate internal air rather than pulling in air from outside
• Avoid:
  • Outdoor exercise (e.g. running, cycling) before and during storms
  • Mowing the lawn or being near fields and grassed areas
• Make sure you:
  • Have your blue/grey reliever and, ideally, a spacer handy
  • Know and follow your Asthma Action Plan if symptoms start

Face masks (even tight cloth or surgical masks) are not very effective at stopping the tiny particles that cause thunderstorm asthma, so don’t rely on them alone.

Step 5: If Symptoms Start During a Storm

If you start to wheeze, cough, or feel short of breath during a storm:

1. Follow your Asthma Action Plan (or standard Asthma First Aid if you don’t have one yet).
2. Use your reliever inhaler with spacer as directed by your plan.
3. Stay indoors in a well-sealed room, sitting upright.
4. If you are not improving within minutes, symptoms are getting worse, or you’re having trouble speaking, call 000 immediately and say you are having an asthma attack.

After the event (once you’re safe), book a review with a GP – telehealth is often fine for this – to:

• Review what happened and whether your medication needs adjusting
• Update your Asthma Action Plan
• Arrange any follow-up tests or referrals (e.g. to a respiratory physician or allergist)

Thunderstorm Asthma and Kids

Thunderstorm asthma doesn’t just affect adults.

Children with:

• Known asthma
• “Seasonal allergies” or hay fever in spring
• A history of wheeze with colds or exercise

may also be at increased risk during thunderstorm asthma events.

Key steps for families:

• Make sure your child has a current Asthma Action Plan that specifically covers spring and storms.
• Provide a puffer and spacer for school, clearly labelled, and ensure it’s not empty or expired.
• Talk to teachers and school staff about your child’s asthma triggers and what to do on high‑risk days.
• Encourage older kids and teens to understand their own plan so they can recognise early warning signs.

Telehealth can be very helpful for busy parents – you can discuss your child’s asthma via phone or video, often after school hours, rather than dragging a wheezy child into a waiting room.

Looking After Your Mental Health Too

If you lived through the 2016 events in Victoria or have had a scary asthma attack yourself, it’s completely understandable to feel anxious whenever storm clouds roll in.

Some ways to manage that anxiety:

• Focus on what you can control: your preventer use, action plan, and staying indoors at key times.
• Keep your reliever and spacer where you can see them – being prepared often reduces fear.
• Talk to your GP (telehealth or in person) if fear of storms is starting to impact your daily life – support for anxiety is just as valid as support for asthma itself.
• Involve your family: make a household plan (“who grabs the puffer, who checks the app, who calls 000 if needed”).

Knowledge and preparation are some of the best antidotes to fear.

How Telehealth in Australia Helps You Stay Storm-Ready

Telehealth is now a permanent and well‑established part of Australian healthcare, and it’s incredibly useful for managing respiratory health outside of emergencies.

At NextClinic, we specifically designed our telehealth services to make it easier to stay on top of conditions like asthma and hay fever – without long travel, long waits, or taking half a day off work.

Here’s how we can support you around thunderstorm asthma season:

1. Asthma and Hay Fever Check-Ups from Home

Through an online telehealth consultation, our Australian-registered doctors can:

• Review your asthma control and recent symptoms
• Update or start your Asthma Action Plan
• Adjust medications (e.g. preventer dose tweaks for pollen season)
• Optimise hay fever treatment

You can read more about this in our blog post “Asthma Check-Up via Telehealth”, which explains exactly how an online asthma review works and how to prepare for one.

2. Online Prescriptions for Preventers and Relievers

Running low on your preventer or reliever inhaler just as the pollen count spikes is the last thing you want.

Via telehealth, we can:

• Provide online prescriptions (eScripts) for your regular asthma and hay fever medicines, when clinically appropriate
• Send the script straight to your phone or your preferred pharmacy
• Help ensure you don’t miss doses leading into spring storms

If you’re interested, you can start with a standard telehealth consultation on our Online Doctors: Telehealth Consultations page, where we also manage other respiratory issues like sinusitis and URTIs.

3. Medical Certificates When You Need Time Off

A bad asthma flare-up – thunderstorm-related or otherwise – can leave you exhausted.

If you need a day or two off work or study to recover, we can issue online medical certificates for sick leave (where clinically appropriate) via:

• Our dedicated Doctor’s Certificate Online service, or
• A full telehealth consultation if you’re also needing treatment and a multi-day certificate

This is especially handy if you’re too unwell to travel or live far from a GP clinic. You can explore more on our “Medical Certificate for Work” and related pages.

4. Specialist Referrals Without the GP Waiting Room

If you need to see a respiratory physician or allergist for further testing (for example, after a thunderstorm event or repeated spring symptoms), our doctors can:

• Assess your situation via telehealth
• Provide a specialist referral letter online, if appropriate
• Help you access more detailed investigations (like spirometry or allergy testing) closer to home

Again, none of this replaces 000 and emergency care if you are acutely unwell – but it can dramatically improve your baseline asthma management, which is your best defence when storm season hits.

Bringing It All Together: Stay Ahead of the Storm

Let’s recap the most important takeaways about thunderstorm asthma:

• Thunderstorm asthma is real and serious – it has caused thousands of emergency presentations and multiple deaths in Australia, particularly in south‑eastern states.
• It happens when high grass pollen and specific thunderstorm conditions combine, creating clouds of tiny allergen particles you can breathe deep into your lungs.
• You’re at higher risk if you have asthma, spring hay fever, or undiagnosed wheeze, especially if your asthma isn’t well controlled or you don’t use a preventer.
• The best protection is prevention:
  • Daily preventer inhaler if prescribed
  • A current Asthma Action Plan
  • Good hay fever control
  • Checking weather and pollen forecasts in spring
  • Staying indoors before and during storms on high‑risk days
• Telehealth in Australia, including our team at NextClinic, makes it easier than ever to:
  • Review your asthma and hay fever
  • Update your action plan
  • Renew prescriptions
  • Get medical certificates or referrals when you need them

Your Challenge This Week

Pick one practical step to improve your thunderstorm asthma safety – and actually do it this week. For example, you could:

• Book a telehealth asthma review to create or update your Asthma Action Plan
• Check your inhalers and make sure your preventer and reliever aren’t expired or empty
• Download a pollen and thunderstorm warning app relevant to your state
• Talk to your child’s school about their asthma and hay fever management
• Set a daily reminder during spring to check the forecast for storms and pollen

Once you’ve chosen and completed your action, we’d love to hear from you.

What did you do to protect your lungs this storm season, and how did it go?

Share your experience or questions in the comments – your story might be exactly what another Aussie needs to breathe a little easier this spring.

References

• Epidemic Thunderstorm Asthma Program | health.vic.gov.au
• Thunderstorm asthma | healthdirect
• Thunderstorm asthma in Australia
• Epidemic thunderstorm asthma risk forecast | health.vic.gov.au
• Thunderstorm asthma - National Asthma Council Australia
• Thunderstorm Asthma and Climate Change | Public Health | JAMA | JAMA Network
• Find out if you are at risk of thunderstorm asthma - Asthma Australia
• Australian Asthma Handbook | Thunderstorm asthma
• Telehealth and Rural Australia: Closing the Gap | NextClinic