Forecast

A brief review of the 2024 pollen season

The 2024 pollen season was not easy to predict due to numerous factors. Looking at the main allergens in Austria, only the grass pollen season showed a normal course of the season. Hazel and alder started their flowering period earlier than usual, while the pollination period of birch ended very abruptly and before the long-term average. However, the flowering of mugwort and ragweed was unusual as well. Both showed a clear break in mid-September, which can be attributed to the heavy rainfall and flooding in eastern Austria. After this extreme weather event the ragweed pollen season then returned to a pattern similar to the long-term average, while the mugwort pollen season showed another interesting development. There was a clear second peak in exposure due to the establishment of additional mugwort species, leading to an extended period of allergenic burden.

Thanks to the users of the pollen diary, the network of over 20 monitoring stations, the forecasting models and the regular phenological observations, we have been able to draw on a wide range of information sources to keep the text forecasts as accurate as possible.

What happens next?
Around Christmas, the flowering of the Spaeth’s alder is expected to cause local allergenic burden. This tree is sometimes found in parks and gardens and flowers around the turn of the year. Representative model data for the onset of flowering from hazel and alder is expected to be available by mid to late December.

We will continue to monitor the situation and keep you updated!