Forecast

The heatwave will peak this weekend, whilst the grasses continue to release dust and cause pollution!

In the second half of the week, Lower Austria will be sunny, dry and hot. The heatwave is expected to peak on Saturday and Sunday, with maximum daytime temperatures of between 35 °C and 40 °C. Under these weather conditions, pollen will be released unhindered and moderate to high pollen levels are to be expected. With these high temperatures, ground-level ozone levels will rise, particularly in urban areas. Ozone can exacerbate the effects of pollen.

Grasses continue to flower from the Waldviertel to the Schneeberg. However, the main flowering activity is now concentrated in the higher elevations of the Industrie-, Most- and Waldviertel regions. Unfortunately, a walk in the woods offers no relief to people who are sensitive to grasses, as forest grasses are now also beginning to flower. In the Danube region, the Vienna Basin and the Weinviertel, grass pollen concentrations are falling slightly, but they continue to fluctuate between moderate and high levels. Currently, floweringfinger millet, couch grass, brome grass, as well as meadow grass, reed grass, rye grass, dogtail grass, cock's foot grass and foxtail grass demonstrate the diversity of native grass species. If the wind is blowing in the right direction, symptom-triggering amounts of grass pollen can be carried from the mountainous regions down to the lowlands, particularly in the afternoon, thereby increasing the local pollen load. Sorrel and plantain species are also continuing to flower and may contribute to the pollen load.

Note: During thunderstorms with increased lightning activity, pollen grains may burst open. This can release large quantities of the allergen into the air, leading to very sudden spikes in pollen levels, known as ‘thunderstorm asthma’.

Only a few individual flowering green alder trees can now be found at higher altitudes in the Most and Industrie districts. Green alder is of particular relevance to people who are sensitised to birch pollen, as cross-reactions may occur. When hiking in the mountains, this group of people should avoid the immediate vicinity of green alders that are still in flower.

In Lower Austria, sweet chestnut and privet are still in flower. The sweet chestnut is cultivated in Lower Austria solely as an ornamental plant and can trigger cross-reactions in people who are sensitive to beech or birch trees. People with allergies who react to olive trees should avoid the immediate vicinity of privet hedges. 

Whilst the lime tree is still in full bloom at higher altitudes, it has largely finished flowering in the lowlands of Lower Austria. Its flowers are adapted to pollination by insects, which is why its pollen is rarely found in the ambient air. However, the scent of the flowers can trigger respiratory problems in sensitive individuals. 

In locations with favourable climatic conditions, the first mugwort plants ready to flower have already been spotted. They may cause initial exposure locally.

At our monitoring stations, allergy-relevant levels of fungal spores are now being detected regularly. The hot, dry weather is dampening the spread of fungal spores somewhat, as fungi release more spores following rainfall.

In addition to the pollen types already mentioned, pollen from nettle plants, umbellifers, elder, pine, rhododendron and cypresses is currently also present in the pollen spectrum. However, these pose only a very low allergenic risk.