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Pollenservice Wien

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: Ragweed pollen season 2026

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The plants are somewhat later in their development locally in the East of Austria, but now the flowers became visible (Video ©Katharina Bastl (MedUni Wien/Pollenservice Wien)): you can surmise the yellow dust (=pollen) in the flowering buds. Thus, local pollination starts.

The flowering time of ragweed (Ambrosia sp.) is from August to September. The ragweed pollen season has started already, because relevant long distance transport of pollen was measured in the end of July.

Current pollination

MONDAY, 21. SEPTEMBER
Pollen types:Fungal spores, Ragweed, Mugwort

LEGEND

Hardly/no pollination
Pollination
high pollination

Due to current cause:

The weed pollen season expires: the  flower of ragweed (Ambrosia) fades; the second flowering phase of Artemisia (mugwort/wormwood) due to neophytes has begun.

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: the second flowering phase of Artemisia has begun; the flowers of annual mugwort (left) are very small, the flowers of Chinese wormwood are bigger and resembling more those of the native species common mugwort, that has flowered in summer time.

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.

Ragweed (Ambrosia) fades; mugwort pollen is in the air again due to the autumn flower!

The ragweed pollen season fades. High pollination is not expected anymore, although ragweed pollen will still be present in the air in certain quantities.

New in the pollen spectrum: Mugwort pollen is measured again. The autumn flower, the second flowering phase, that was measured for the first time in 2023 has begun. It is caused by the neophytes annual mugwort and Chinese wormwood (see Figure). They profit from a mild autumn. It is questionable if an intense flower like 2023 or 2024 is possible this season. However, increasing pollination has to be expected from a current point of view.

The flower of reed ends. Grass pollen hardly occurs in the air samples.

The main season of fungal spores is fading. Currently, spore concentrations are high, typical for mild autumn days. Spore concentrations are dominated by Cladosporium and Alternaria spores in the air. However, due to the prolonged dry weather, the fungal spore season was below average this year up to now.

Pollination profile
Ragweed:
state of the flower: end of the main pollination period/pollination
trend: decreasing
time of the start of the flower: later than average

Fungal spores:
state of the season: end of the main period/high spore concentrations
trend: constant
time of the start of the season: average

Mugwort/wormwood:
state of the flower: begin of the second pollination period/low pollination
trend: increasing
time of the start of the flower: average

You can find the typical pollen seasons in our pollen calendar

Pollen spectrum:
Pollen from ivy, mercury, the goosefoot family and the nettle family is also in the air.

Current main allergen: Fungal spores

Exposure time in Vienna: May to October

Occurrence in Vienna: The molds in focus here thrive on vegetation. This ranges from potting soil to grain fields. Note: The concentration of fungal spores outdoor has nothing to do with the occurrence of molds indoors.

Who are “the fungal spores“?
The spores of the molds Alternaria and Cladosporium are of allergological importance, especially the former. The here discussed fungal spores are the most important ones for ambient air. There is a high diversity of molds, that are present indoors and can spread on food. Molds may cause allergies, but also toxic reactions escalating to mycosis (invasion of the inner organs).
Alternaria belongs to the blackness-fungi. It grows primarily on vegetation and causes plant diseases that can result in crop failures (fruit, cereals). Persons concerned should not mow the lawn, since it is often located on dry plants. However, Alternaria is also found in the living area.
Cladosporium belongs as well to the blackness-fungi. It prefers forests, gardens, and swamps. It is the most common fungal spore in ambient air.

Cross-reactivity: In general, there is cross-reactivity to spores of other molds (e.g. Aspergillus, Epicoccum).

Current main allergen: Ragweed

Pollination time in Vienna: August to October

Occurrence in Vienna: Ragweed prefers disturbed land and occurs mainly on construction sites, along railway embarkments, motorways, roadsides, on farmland and fields (maize, sunflower) on the outskirts of Vienna.

Who is “the ragweed“?
Ragweed, common hogweed, annual ragweed, low ragweed (Ambrosia artemisiifolia): This is the most common ragweed species in Vienna. It was introduced as a neophyte and is meanwhile well established especially in the East and South of Austria. This species is annual and may grow up to 1,8m. It can occur also around bird houses and gardens due to contaminated bird food.
Perennial ragweed (Ambrosia psilostachya): This species produces less seed because it spreads mainly through their roots.
Giant ragweed (Ambrosia trifida): It possesses three-feathered leaves in contrast to other species of ragweed (feathered leaves) and may grow until 4m height.

Cross-reactivity to pollen of other plants: to other genera within the same family of composite plants (Asteraceae), among others mugwort

  • The Pollenservice Vienna is part of the University Department of Otolaryngology, Head and Neck Surgery at Medical University of Vienna.
  • The collaboration with GeoSphere Austria involves comparing forecasts and exchanging pollen and weather data. 
  • The Pollenservice Vienna is official partner of the Gesundheitsdienst (MA15) of the City of Vienna.