We’re halfway through the grass pollen season– so how are things looking?

Earlier in the year, we predicted that this pollen season would look a lot like last year. But there was a catch – the outlook for this year’s season would depend heavily on spring rainfall.

At the start of spring, there was a 60%-80% chance of above-average rainfall in most areas across the state. Luckily for allergy suffers, rainfall during October was average to below-average across most of the state (Figure 1). This means that Victoria has experienced a dry, warm winter followed by a dry, warm spring- both of which have limited grass growth due to dry soils.

Figure 1. Victorian Rainfall Deciles for October 2024. For most of the state, rainfall has been average (white) or below average (red). In the southernmost and eastern corner, rainfall has been the lowest on record. Some pockets in the north have had slightly above average rainfall (blue). Image adapted from the Bureau of Meteorology.

As a result, the 2024 pollen season is shaping up to be a mild one - well below average. In Melbourne, we are seeing that while the season began fairly similar to last year and the long-term average, during November the trend has fallen to below average (Figure 2).

Figure 2. Comparison of cumulative grass pollen for 2024 (red) compared to the last 5 years (2020=orange, 2021=pale blue, 2022=dark blue, 2023=green) and the long-term average since 2000 (grey) for Melbourne.

Taking a look at a few of the other monitoring sites around the state, we see similar trends for Creswick, Churchill, and Geelong. The season started off as usual, but as we entered November the trend has dropped to well below-average levels of pollen. In the case of Dookie, we actually see that there were slightly above-average grass pollen levels during mid-October, which are now trending towards the long-term average.

Figure 3. Comparison of cumulative grass pollen for 2024 (red) compared to the last 5 years (2020=orange, 2021=pale blue, 2022=dark blue, 2023=green) and the long-term average since 2017 (grey) for (clockwise) Dookie, Churchill, Creswick, and Geelong.

So, what does this mean? This year, we are experiencing an average to below-average pollen season. The low grass pollen levels are mainly being driven by limited rainfall and dry soil conditions. It’s worth noting that in the last 5 years, the heaviest seasons have occurred during the three successive La Niña events of 2020-2022, which brought much wetter conditions.

Here’s some great news: the grass pollen season looks like it’ll wrap up right on time this year, around late December to early January. Most grasses follow a yearly routine – after they produce seeds, they stop growing and start to dry out, a process called curing. We keep tabs on this by checking out the Victorian grass curing maps, which show how much of the grasslands have cured. This year’s map is pretty similar to last year’s, though the grasses are slightly less cured (see Figure 4). What does that mean for you? By Christmas, the chances of high or extreme grass pollen days should be super low.

Figure 4. Grassland curing percentage for 11/11/2024 compared to 13/11/2023. Images adapted from the CFA.

We are expecting to see the same or fewer days with high and extreme grass pollen levels this year compared to last year. High and extreme grass pollen days are our worst for hay fever and asthma. But for those with allergies, don’t let your guard down yet– the forecast is still for another 11 high and extreme pollen days before the end of the year. So please continue to stay alert and take steps to protect your health this season.

How to prepare

For those affected by hay fever or asthma, preparation is crucial. Stay informed by tracking daily pollen counts via the Melbourne Pollen App and adjust your plans on high pollen days. Make sure to consult with healthcare providers to have an action plan in place, especially if you suffer from asthma or allergies.

Where to get Pollen Information

The Melbourne Pollen App is available on both the Apple and Google Play Store , offering real-time notifications about pollen levels. You can also follow the Melbourne Pollen team on X (formally Twitter)and Facebook for updates.