Situation and medium-term forecast for

Issued 10th of May 2021

Situation and medium-term forecast

Summer-like temperatures lead to increased pollination!

Due to the rapidly increasing temperatures on the weekend plants made a major developmental step, especially the grasses. Their pollen will be the most important aeroallergen during the next months. During the first half of the week sunny and dry weather is expected for the whole country which results in excellent conditions for pollination. From Thursday until the weekend more unfavorable conditions will then lead to reduced pollen concentrations and therefore reduced burden for pollen allergy sufferers.

Currently the fast developing grass species like foxtail grass reach the readiness to flower. At climatically favored areas this is also the case for meadow grass and orchard grass. At theses locations low to moderate burden has to be expected for grass pollen allergy sufferers. Until grass pollen leads to allergenic burden throughout the country, more individuals need to start flowering.

The white flakes floating in the air are poplar wool, which itself does not irritate. It is just the seed and seed hair from poplar. However, irritation is often wrongly attributed to it because the occurrence of poplar wool usually coincides with grass pollination.

The onset of the flower of green alder has to be expected in higher elevated regions and areas of growth. Pollen arrives in mostly a low amount also in the lowlands, but the main burden is found in mid- to high-altitude regions. Green alder pollen might concern alder and birch pollen allergy sufferers.

The birch pollen season fades with mostly low values. Caused by long distance transport of birch pollen from northern Europe, allergenic burden might be increased shortly.

Oak is still flowering and may lead to allergenic burden for birch pollen allergy sufferers due to cross reaction.

In urban areas Manna-Ash is flowering. In difference to the common ash, this cultivated species from the Mediterranean is partly insect pollinated and therefore not responsible for such high pollen concentrations. Due to long distance transport from Austria’s southern neighboring countries still some allergenic burden has to be expected for ash pollen allergy sufferers.

Plane tree has passed its peak pollination period. Allergenic burden still has to be expected in cities or close to avenues of plane trees.

What else: The pollen spectrum contains pollen from horse chestnut, yews, cypresses, sedges, ginkgo, walnut, mulberry, fir, spruce, rose family, dock and willow in addition, which is of a low allergological importance.


We expect the readiness to flower for grasses inon
St. Pölten12.05.2021

Forecast from 10.05.2021
Note: The model results give an indication of the expected start of flowering, based on information provided by local pollen warning services with direct reference to the local situation. Readiness to flowering is not equal to the beginning of the pollen season. When the start of flowering is achieved, most of the plants can release pollen, but only when weather conditions are favourable.

Responsible for the content: and the Department of Oto-Rhino-Laryngology of the Medical University Vienna, Research group aerobiology and pollen information
Uwe E. Berger MBA, Mag. Maximilian Bastl PhD and Mag. Dr. Johannes Bouchal
medium-term forecast based on model and pollen data from Austria and surrounding countries
reprint and publication in parts or completely is permitted only quoting the source

weather data and today´s forecasts based synoptic data: ZAMG (Zentralanstalt für Meteorologie und Geodynamik)
zum Team

The current pollen load for Austria

Legende: 1 = Low, 2 = Moderate, 3 = High, 4 = Very High

plane tree (Platanus)

Sunday, 16. May
Monday, 17. May
Tuesday, 18. May

ash (Fraxinus)

Sunday, 16. May
Monday, 17. May
Tuesday, 18. May

birch (Betula)

Sunday, 16. May
Monday, 17. May
Tuesday, 18. May
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