Spring brings warmer days and more time outdoors, but for many Australians, it also marks the return of hay fever season. And in parts of Victoria, the 2026 pollen season could be particularly active.

Victoria experienced its wettest winter in a decade, with Melbourne recording its warmest winter on record. The combination of abundant moisture and above-average temperatures encouraged grass growth across parts of the state, with experts predicting more extreme grass pollen days in western and central Victoria this spring. Tree pollen had already produced several extreme ratings before the official grass pollen season began on 1 October.

For most people affected by seasonal allergies, higher pollen levels may mean an unwelcome return of hay fever symptoms. But pollen can affect more than just your nose and eyes.

For people with asthma or springtime hay fever, high grass pollen levels combined with certain thunderstorms can create the conditions for thunderstorm asthma — and breathing difficulties can sometimes develop even in people who have never previously been diagnosed with asthma.

Why can hay fever be so bad in spring?

Hay fever — also known as seasonal allergic rhinitis — occurs when your immune system reacts to airborne allergens such as pollen.

For someone with a pollen allergy, breathing in these tiny particles can trigger inflammation and symptoms such as:

sneezing
a runny or blocked nose
itchy nose or throat
watery, red or itchy eyes
coughing.

Exactly when symptoms appear can depend partly on the type of pollen you're sensitive to because different plants release their pollen at different times.

In Victoria, for example, pollen from trees such as cypress can become a problem earlier in spring. Melbourne had already recorded several extreme tree-pollen ratings by September 2026. Grass pollen season typically runs from October through December, with the highest levels generally beginning around mid-October.

Why can Melbourne be particularly bad for pollen?

Large areas of pasture to Melbourne's north and west grow grasses such as ryegrass. When these grasses flower, they can release substantial amounts of pollen into the atmosphere.

Weather then helps determine where that pollen goes.

Northerly winds can carry pollen produced in surrounding grasslands towards metropolitan Melbourne. Geography can also affect exposure, with pollen concentrations varying considerably between different parts of the city and state.

This year, the conditions leading into spring have added another factor.

Victoria's warm, wet winter encouraged grass growth, creating conditions that could result in more pollen being produced when those grasses flower. RMIT respiratory researcher Dr Hao Wang described Melbourne's combination of tree and grass pollen, prevailing winds and unpredictable spring weather as contributing to its unusually challenging allergy environment.

However, that doesn't necessarily mean every part of Victoria will experience the same season. Current forecasts suggest western and central Victoria may experience greater pollen activity, while drier conditions could result in a more subdued season in Gippsland.

Do other parts of Australia get hay fever season too?

Melbourne may have a reputation for troublesome spring pollen, but hay fever certainly isn't limited to Victoria. Pollen allergies occur across Australia, although when symptoms are most likely to flare — and which pollens are responsible — can vary considerably depending on where you live.

Australia's size and different climates mean there isn't one single nationwide “pollen season”. Trees, grasses and weeds flower at different times of year, while local rainfall, temperature and wind can all influence how much pollen becomes airborne and where it travels.

In southern parts of Australia, including Victoria, South Australia, Tasmania and parts of New South Wales and Western Australia, allergenic grasses tend to have their main flowering period during spring and early summer. The main grass-allergy season in southern Australia is generally October, November and December.

Further north, however, the timing can look quite different. In northern coastal areas, subtropical grasses are more prominent and commonly flower later, with grass-allergy season generally occurring around January, February and March. This means someone living in Queensland, for example, may experience their strongest grass-pollen symptoms at a different time from someone living in Melbourne.

Geography also matters. The Australasian Society of Clinical Immunology and Allergy (ASCIA) notes that pollen counts tend to be lower along parts of Australia's east coast, where winds frequently arrive from the sea and the Great Dividing Range provides some protection from westerly winds. In South Australia and Western Australia, pollen levels can vary considerably depending on wind conditions.

And it's not only grass pollen that matters. Depending on where you live and what you're allergic to, tree and weed pollens can cause symptoms at other times of the year, meaning some people may experience pollen-related hay fever well outside the traditional spring period.

What's the connection between hay fever and asthma?

Hay fever and asthma are different conditions, but the two can be closely connected.

Hay fever primarily affects the upper airways, particularly the nose and nasal passages. Asthma affects the lower airways within the lungs, where inflammation and narrowing of the airways can make breathing difficult.

The symptoms can therefore look different.

Someone experiencing hay fever may notice sneezing, an itchy or blocked nose and watery eyes, while asthma can cause symptoms such as wheezing, coughing, shortness of breath and chest tightness.

For some people, however, pollen can contribute to symptoms in both the upper and lower airways. This becomes particularly important during grass pollen season because people with springtime hay fever caused by grass pollen can be at risk of thunderstorm asthma, even if they haven't previously been diagnosed with asthma.

That's one reason breathing difficulties during pollen season shouldn't simply be dismissed as particularly bad hay fever.

What exactly is thunderstorm asthma?

Despite the name, thunderstorm asthma doesn't mean that every thunderstorm is likely to trigger asthma.

It develops when a particular combination of high grass pollen levels and certain thunderstorm conditions occurs.

Normally, whole grass pollen grains are relatively large. During certain thunderstorms, however, moisture can cause pollen grains to rupture, releasing much smaller allergen-containing particles.

Strong winds and storm outflows can then concentrate and carry these tiny particles through the air.

Because the particles are much smaller than the original pollen grains, they can be inhaled deeper into the lungs, where they may trigger asthma symptoms in susceptible people.

Can you get thunderstorm asthma if you've never had asthma?

Yes — and this is one of the reasons awareness during grass pollen season is important.

People with known asthma can be at risk, particularly if their asthma isn't well controlled. However, thunderstorm asthma can also affect some people who have springtime hay fever or grass pollen allergy but have never previously been diagnosed with asthma.

This happened during Melbourne's major epidemic thunderstorm asthma event in November 2016, when many of the people who developed breathing difficulties experienced what appeared to be their first asthma attack.

So, if you normally think of yourself as someone who “just gets hay fever”, it's still worth recognising the difference between your usual allergy symptoms and signs that your lower airways may also be affected.

Symptoms such as wheezing, shortness of breath, chest tightness or persistent coughing shouldn't simply be assumed to be ordinary hay fever.

How can you prepare for hay fever and thunderstorm asthma season?

Before spring and pollen season

Keep taking your prescribed asthma medicines as directed by your doctor, including any preventer treatment you have been prescribed.
Book an asthma review with your GP and make sure your asthma action plan is up to date.
Check your inhaler technique to make sure you’re using your medication correctly.
Know asthma first aid so you know what to do if you or someone around you develops asthma symptoms.
Make sure you have your medications available, including your reliever inhaler if you have asthma.
If you regularly experience springtime hay fever, speak with your doctor or pharmacist about how to manage your symptoms before pollen levels begin to rise.

During pollen season

Continue taking your asthma and hay fever medicines as directed. Don't stop prescribed treatment simply because you're feeling well.
Carry your reliever inhaler with you if you have asthma.
Check pollen counts and weather forecasts regularly, particularly during spring and early summer, so you can plan ahead for high-pollen days.
If pollen levels are high, consider limiting unnecessary time outdoors, particularly if you know pollen triggers your symptoms.
Consider wearing a face mask when you need to be outdoors, particularly on high-pollen days. A mask may help reduce your exposure to airborne pollen allergens while you're outside.
Keep windows and doors closed when outdoor pollen levels are particularly high to help reduce the amount of pollen entering your home.
Keep an eye on thunderstorm asthma forecasts and alerts where these are available.

When thunderstorm asthma risk is elevated

Certain thunderstorms combined with high grass pollen levels can create conditions for thunderstorm asthma. If you're at risk:

Stay indoors before and during thunderstorms with strong wind gusts, particularly during grass pollen season.
Close windows and doors before the storm arrives.
If you're using an air conditioner that brings in outdoor air, switch it to recirculate/recycle mode where possible.
Avoid going outside during the gusty winds that can occur before a thunderstorm, even if it hasn't started raining yet.
Keep your reliever inhaler accessible if you have asthma.
Follow official weather, pollen and thunderstorm asthma alerts for your area.

What if you have hay fever but not asthma?

Having springtime hay fever — particularly an allergy to grass pollen — can still put you at risk of thunderstorm asthma, even if you've never previously been diagnosed with asthma.

Manage your hay fever appropriately and speak with your doctor or pharmacist about suitable treatment.
Avoid being outside in gusty winds before and during spring thunderstorms when pollen levels are high.
Don't dismiss wheezing, shortness of breath, chest tightness or persistent coughing as simply another hay fever symptom.
If you experience asthma-like breathing symptoms for the first time, seek medical advice.
If you or someone around you develops severe breathing difficulty, follow asthma first aid and call Triple Zero (000) in an emergency.

Don't forget about your indoor environment

Staying indoors can help reduce exposure when outdoor pollen levels are particularly high, but it's also worth paying attention to the environment you're spending that time in.

Pollen can enter homes through open windows and doors and can also be carried indoors on clothing, shoes and pets. Keeping windows and doors closed during particularly high-pollen conditions may help limit how much outdoor pollen enters the home.

Regular cleaning can also help manage dust and allergens that accumulate indoors, while addressing dampness, mould and poor indoor air quality can help create a more comfortable indoor environment.

That doesn't mean keeping your home permanently sealed. Ventilation remains important for indoor air quality, so the aim is to be strategic — for example, considering outdoor pollen and weather conditions when deciding when to open windows.

Read related article: How Poor Air Quality in Your Bedroom is Ruining Your Sleep

Be ready before the next high-pollen day

You can't control how much pollen the grasses around Victoria produce or what the spring weather will bring. But you can know when conditions are changing and prepare accordingly.

Spring pollen may be unavoidable, but knowing what to watch for and what to do when conditions change can help you head into the season better prepared.

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October 08 2026, by Tatianna Gerard Spring Hay Fever Is Back: Are You Prepared for Pollen & Thunderstorm Asthma?