We provide here pollen forecasts and recommendations, that are based on our scientifically evaluated data and our expertise. It is our aim to inform persons concerned by pollen allergies in Vienna in a most comprehensive, accurate way and free of charge.
Video Highlight: Dusting purple alder 2026
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The purple alder usually begins to flower during Christmas week. Due to its hybridization between Japanese and Caucasian alder, the tree copes well with lower temperatures and can release pollen even at just above 0°C. Due to the persistent cold weather in January, pollen release during the main flowering period was delayed until the end of January.
Current pollination
LEGEND
Due to current cause:
The pollen season starts this year later than in the last years when defined with the begin of the flower of hazels, although it will be most probably within the mean of the climatological normal. We provide this convenient overview graph to visualize pollination during the calendar year besides our pollen calendars.
You find more about this seasonal overview here.
Copyright: MedUni Vienna, www.pollenservice.wien
Figure: catkins of common hazel, that are ready to flower (bottom right), flowering catkins of Spaeth´s alder (bottom left) and closed catkins of Turkish hazel (top right) and of grey alder (top left).
Mid- and long-term forecast for Vienna
This forecast gives you an overview for a longer time period so that you can improve your planning.
First hazel catkins are ready to flower - season delayed due to weather conditions!
The early flowerers had to wait this year and an early start like in the last years was not possible. First hazel individuals are ready to flower and first pollen grains were recorded in the air samples in the beginning of this week. However, the weather situation for the next days will prevent pollen release and delay the start of the main pollination period.
Spaeth´s alder is in full flower and took advantage of the favorable weather conditions at the beginning of the week (see video highlight). However, the current weather situation (rain and fog) is once again preventing pollen release and postponing the last remnants of full flower until the next more favorable phase. The purple alder (Alnus x spaethii) is a hybrid of Japanese and Caucasian alder that only occurs in areas where it is planted. It is so rare in Vienna that it does not cause any measurable pollen dispersal.
The native alder species are still dormant.
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