The 2026 Australian pollen season has started, with some people in the eastern states reporting their hay fever symptoms have begun earlier than normal.
Compared to last year, satellite imaging suggests eastern states have experienced more vegetation growth during late winter and early spring.
Meanwhile, Western Australia has lower levels of plant growth, likely due to lower than usual rainfall. This may mean a slower start to the pollen season.
Plant growth is an important predictor for pollen season severity, as greater growth can lead to earlier flowering and increased pollen production. Spring rainfall over the next few weeks will also be crucial in determining the severity of the pollen season.
How does pollen cause hay fever symptoms?
Pollen is produced as part of a plant’s annual reproductive cycle. Male flowers produce pollen, which is distributed to female flowers by insects, birds and the wind.
When the wind disperses pollen grains, they can travel great distances in the air, and when we breathe in, we can inhale them. Once in the nose, eyes and lungs, proteins on the surface of the pollen, and small pollen fragments, interact with our cells.
In people with pollen allergy, this can trigger an immune response that causes hay fever symptoms, including sore and itchy eyes, sneezing and coughing.
When pollen enters the lungs, it can also trigger asthma attacks. This is more likely to occur during thunderstorms, when changes in air pressure and humidity cause pollen grains to rupture. Fragments of pollen can travel deep into the lungs, making it harder to treat the resulting asthma.
What are the most common hay fever causes?
Hay fever, or allergic rhinitis, affects nearly one in four Australians. The most common cause of seasonal hay fever is grass pollen from a range of different grass species.
Some people get hay fever from tree and weed pollen, particularly from certain conifers and European trees such as pines, planes and olives.
Trees often release pollen early in the season, followed by grasses and weeds. Pollen calendars can indicate the likely timing and duration of pollen release for particular plant species.
Some plants release pollen more rapidly than others, over just a few weeks, while the most common allergen, grass pollen, is released throughout the season. This means different people have hay fever symptoms for different lengths of time, depending on which species they’re allergic to.
So has the pollen season started early?
Researchers define pollen seasons when concentrations in the air exceed a certain level. This usually occurs in spring, peaks in early summer and finishes with the end of summer, or when hot conditions slow pollen release.
Historically the pollen season in Melbourne and Canberra has been considered to extend from the start of October to December, and in Sydney from September to December. Peaks come in October (for Melbourne and Canberra) and September (Sydney).
Less is known about the timing of the peaks in other states and territories such as WA, South Australia and Tasmania, although research is underway to answer these questions.
This season may have started earlier in eastern states, due to the strong vegetation growth, while other areas, such as WA may be experiencing a delayed start.
When there is adequate rainfall for strong plant growth, this can increase the potential for plants to produce pollen over the season.
However daily rainfall patterns can also help wash pollen out of the air, depending on rainfall intensity, giving some relief for hay fever suffers.
How do climate patterns affect pollens?
The start, peak and severity of pollen seasons can vary considerably across Australia due to differences in weather patterns, environmental conditions and underlying geography.
Transient climate patterns, such as the current El Niño event, can influence pollen levels. While associated hot and dry conditions across the country could favour pollen transport and pollen fragmentation, if drought conditions occur as a result of low rainfall, pollen production will decrease, reducing the severity of the pollen season.
Climate impacts on pollen seasons are equally complex. Predictions of pollen abundance under climate change scenarios show different plant species may respond differently to warming conditions. Common allergenic species may reach higher or lower annual pollen levels in the future.
How to check the pollen count in your area
Australian researchers have developed forecasting models and the real-time pollen monitoring tool, AirRater, with a free app for monitoring pollen and air quality. This helps hay fever suffers monitor their exposure, manage their symptoms and appropriately time medications to coincide with periods of high pollen exposure.
As part of our research, we are mapping individual trees to gain a better understanding of pollen dispersal and local pollen patterns. We are working to develop this into a tool which can complement existing strategies and help people further reduce their exposure.
How to stay on top of your symptoms
People with moderate or mild symptoms can use oral antistamines, eye drops and nasal sprays or corticosteroid nasal sprays to treat their symptoms.
However, if you have severe hay fever symptoms or asthma, or your symptoms interfere with your daily activities or are getting worse, visit your GP to talk about your options and ensure you’re prepared for pollen season.
When hay fever is triggered by grass or common tree pollens, allergy specialists can offer immunotherapy. This involves repeated exposure to low levels of the pollen allergens – through regular injections or sublingual drops given under the tongue – can help to eliminate hay fever symptoms.
But immunotherapy can take 3–5 years to be effective and may not work for everyone.
Mary Hanson, Aerobiologist and Work Integrated Learning Academic Coordinator (Science), Edith Cowan University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
