Victoria has just recorded its wettest winter since 2016 and its warmest winter on record. The latest soil-moisture maps show broad areas of above-average moisture across many of the state’s major pasture and grazing districts, while satellite imagery shows stronger green growth than at the same time last year.

These conditions have given grasses across western, northern and central Victoria a strong start, allowing more plant growth to develop before the main flowering period. However, the picture is not uniform across the state. Gippsland and parts of south-eastern Victoria remain drier and less green, suggesting that the pollen season may be less active in those regions.

The Bureau of Meteorology continues to forecast a warmer and generally drier spring. The key question is how long the moisture already stored in the soil will last. If it carries grasses through September and into flowering, Melbourne and much of western and central Victoria are likely to experience a more active grass pollen season than last year. If unusually warm conditions arrive early and the landscape dries rapidly, the season may be shorter or less intense.

Setting the Scene: How 2025 Played Out

Between October and December 2025, Melbourne recorded 5 extreme, 15 high and 25 moderate grass pollen days. In total, grass pollen reached at least moderate levels on 45 days, including 20 days in the high or extreme ranges. Although Melbourne recorded fewer extreme pollen days than in 2024, the 2025 season still included repeated periods of elevated grass pollen during spring and early summer.

The environmental starting point for 2026 is stronger across much of western, northern and central Victoria. The state recorded 231.2 mm of rain during winter, 13% above the long-term average, making it Victoria’s wettest winter since 2016. It was also Victoria’s warmest winter on record overall. Overnight temperatures were the warmest recorded for any Victorian winter, while daytime temperatures were the equal fourth warmest.

The combination of rainfall and unusual warmth has supported early vegetation growth across many of the pasture districts that contribute grass pollen to the air over Melbourne and surrounding regions. The exception is much of Gippsland, where winter rainfall was below average and current soil moisture remains low.

Soil Moisture Conditions

Soil moisture plays a critical role in determining how much grass pollen ends up in the air. When soils are moist, grasses grow vigorously, develop more leaves and stems, flower fully, and release large amounts of pollen. When soils dry too early, growth slows and pollen production can be reduced.

As Figure 1 shows, root-zone soil moisture is above average across broad areas of western and north-western Victoria. These districts are also substantially wetter than they were at the same time in early September 2025, when soil moisture across much of western Victoria was close to or below average.

In contrast, much of Gippsland and south-eastern Victoria is below average, with some areas substantially drier than they were in early September 2025. Grass growth in these districts may depend more heavily on receiving further rainfall during early spring.

The wetter conditions across western Victoria provide grasses with a strong foundation heading into the growing season. Even if rainfall becomes less frequent during September, water already held through the root zone may continue to support growth. The critical question is how quickly above-average spring temperatures draw down that moisture.

Vegetation Greenness and Growth Potential

Satellite imagery showing vegetation greenness, known as the Enhanced Vegetation Index or EVI, indicates that western Victoria is noticeably greener than it was at the same time last year (Figure 2).

The strongest increase is visible across the broad pasture and grazing districts west and north-west of Melbourne. In these areas, the darker green colours indicate that there is more actively growing plant material across the landscape.

This difference is important because greater vegetation growth means more biomass is available to produce pollen once grasses begin flowering. Pastures and open grasslands across western Victoria have already responded to the wetter conditions, reducing the extent to which the season now depends on further rainfall to initiate growth. Further rain would help sustain that growth and allow grasses to continue developing through spring.

The pattern is different across south-eastern Victoria, where vegetation is less green than it was last year in early September. This suggests that the potential for a large grass pollen season is currently greater across western and central Victoria than it is across Gippsland and the state’s south-east.

Climate Drivers and the Rainfall Outlook

A strong El Niño is now established and is expected to intensify further through spring. The Indian Ocean Dipole, a climate pattern in the tropical Indian Ocean that can influence rainfall across southern Australia, remains neutral. Bureau models continue to suggest that it could become positive during spring, although the predicted strength of any event has decreased in recent forecasts.

These broad climate drivers provide useful background, but the Bureau’s local rainfall and temperature outlook gives the clearest indication of what is expected across Victoria. The latest outlook continues to favour a warmer and drier spring, particularly across southern Victoria (Figure 3).

For September to November, the chance of exceeding median rainfall is below 50% across the entire state of Victoria. The strongest dry signal is across southern, central and eastern districts, where the chance of above-median rainfall is generally around 20% to 35%.

The outlook becomes less dry for October to December across northern Victoria, where the chance of exceeding median rainfall moves closer to 50%. However, below-median rainfall remains more likely across much of southern Victoria, including Melbourne and surrounding districts.

Daytime and night-time temperatures are also likely to be above average, with an increased chance of unusually warm spring days across southern Australia. These conditions are likely to increase the rate at which soils and vegetation dry as spring progresses.

What to Expect in 2026

A drier outlook does not necessarily mean a low grass pollen season. The key question is when the dry conditions arrive and how long the soils remain moist.

Across western Victoria, grasses are beginning spring with considerably more soil moisture and more green growth than they had last year. If that moisture supports continued growth through September and October, grasses may have enough time to build further biomass and begin flowering before hotter conditions dry the landscape.

Once grasses have flowered, warm, dry and windy weather can support the release and movement of pollen through the air. This combination of wet growing conditions followed by warmer, drier weather during flowering could lead to significant pollen levels across western and central Victoria, including Melbourne.

Under this pattern, Melbourne could experience more high and extreme grass pollen days during late October and November than it did last year.

However, if unusually warm weather arrives early in September and the landscape dries rapidly, grass growth and flowering may be cut short. This could reduce the amount of pollen produced and lead to a shorter or less intense season.

South-eastern Victoria is already starting from a drier and less green position. Unless further rainfall arrives, grass pollen levels in those districts are likely to be lower than last grass pollen season.

The next six to eight weeks will determine how much of the current potential is realised. The evidence available right now points to an increased risk of a significant season across western and central Victoria, but the timing of the forecast spring heat will be critical.

• “Victoria’s wettest winter since 2016 has given grasses a strong head start across the pasture districts west and north of Melbourne,” said Dr Edwin Lampugnani, CEO of AirHealth, operator of the Melbourne Pollen service.
• “The latest maps show much wetter soils and more green growth than we saw at the same time last year. That strengthens the likelihood of a more active grass pollen season across Melbourne, western and central Victoria.”
• “The key uncertainty is when the warmer, drier weather arrives. If the heat comes early and dries the landscape before grasses finish flowering, the season could be shorter and less intense. If the moisture lasts into October, the potential for a significant season will be much greater.”

How to Prepare

With the potential for a more active grass pollen season, now is the time to start getting ready. People who experience hay fever or asthma should talk to their doctor or pharmacist about managing symptoms before pollen levels begin to rise. Make sure medications are up to date and accessible, and if you have asthma, ensure you have a written Asthma Action Plan in place.

• “Pollen season is a good reminder to check in on your asthma. Make sure your medicines are right for you, your inhaler technique is correct and your written Asthma Action Plan is up to date. A review with your doctor can help identify problems before they become an emergency,” said Kate Miranda, CEO, Asthma Australia.

To prepare for the weeks ahead:

• * Check daily pollen forecasts on the Melbourne Pollen App (available on Apple and Google App stores).
• * From 1 October to 31 December, check Victoria’s three-day epidemic thunderstorm asthma risk forecast through VicEmergency. Set up a Watch Zone for your home, workplace, school or other important locations so you can receive advice and warnings for your area.
• * Talk to your GP or pharmacist about managing hay fever or asthma symptoms before grass pollen levels begin to rise.
• * If you have asthma, or care for someone who does, make sure your written Asthma Action Plan is current, know the steps of asthma first aid, and keep your medication accessible.
• * Avoid being outdoors on high pollen days, particularly during windy conditions or before thunderstorms.

For more information and resources:

• * Asthma Australia
• * National Asthma Council Australia

The best way to stay informed about how much pollen is in our shared air is to visit the Melbourne Pollen website or download the Melbourne Pollen App (available on Apple and Google App stores). The service provides daily pollen forecasts, push notifications and information to help people plan their activities during the grass pollen season.

The Bottom Line

The 2026 Victorian grass pollen season has the potential to be more active than last year, particularly across western and central Victoria. Victoria has experienced its wettest winter since 2016 and its warmest winter on record, while current soil-moisture and vegetation imagery show that grasses across many of the state’s major pasture districts have had a much stronger start than last year.

The main uncertainty is how quickly the landscape dries. If stored moisture supports grasses through September and into flowering, Melbourne could experience more high and extreme grass pollen days than last year. If unusually warm conditions arrive early and soils dry rapidly, the season may peak earlier and be shorter.

Gippsland and parts of south-eastern Victoria remain drier and less green, so the season is unlikely to be equally active across the entire state. For Melbourne and much of western and central Victoria, however, the balance of evidence now points to a season that people with hay fever and asthma should take seriously.