Forecast

Heat-induced thunderstorms can lead to unexpected spikes in demand

The second half of the week will be hot. However, due to this heat, the sunshine will be accompanied by rain or thunderstorms as the day progresses, particularly in the west and south of the country. As long as it remains dry, people with grass pollen allergies should expect high pollen counts. Any rainfall may only temporarily reduce these levels.
However, if there are not only showers but also thunderstorms, this can lead to the phenomenon known as thunderstorm asthma. This causes pollen grains to burst, releasing a disproportionate amount of free allergen into the air, which can trigger severe allergic reactions.

Grass pollen remains the main allergen. In addition to couch grass, brome grass and smooth oat grass, honey grass, ryegrass, meadow grass, tufted grass and foxtail grass are also responsible for the measurable pollen levels. In meadow areas, additional pollen levels from sorrel and plantain are also possible.
In their growing regions, cereals continue to flower and may cause additional grass pollen levels locally. Pollen from cereal crops such as rye or wheat is significantly larger than that of other grass species and cannot therefore be carried as far by the wind. 

Weather permitting, the green alder causes pollen levels to rise in the mountainous regions of Austria. Its pollen can trigger allergic symptoms in people who are sensitised to other alder species or birch trees. During prolonged dry spells, its pollen can be carried by the wind over long distances to valley floors and low-lying areas, where it can cause symptoms.

In the east and south of Austria, sweet chestnut trees are in bloom and may trigger cross-reactions in people in the vicinity who are sensitised to beech or birch trees.

Also in the east and south of the country, people who are allergic to olive tree pollen should be aware that low concentrations of olive tree pollen may be present in the air. Privet is also of significance for this group of pollen allergy sufferers.

Linden blossom is slowly coming to an end. As the flowers of this plant are adapted to insect pollination, they are generally quite rare in the air. However, their scent can irritate the airways of sensitive individuals. 

At higher altitudes, conifers such as the mountain pine can still be found in bloom. From an allergological perspective, however, this plant is of little relevance.

In some areas, the tree of heaven has already passed its peak flowering period. This is a neophyte from Asia that spreads in nutrient-poor and dry habitats such as railway embankments or wasteland. Allergic skin reactions have already been documented.

In locations with particularly favourable climatic conditions, the first flowering specimens of mugwort have already been spotted. This marks the start of the herb pollen season locally. However, it will still be a few weeks before the plants are in full bloom across the board. Locally, however, there may already be low levels of allergic exposure.

The warm, humid weather conditions are leading to a rise in the concentration of fungal spores in the ambient air and, consequently, to a higher level of exposure for people with allergies. 

In addition to the pollen types mentioned, the current pollen spectrum also includes bee balm, nettles, umbellifers, acid grasses, legumes, spirea, grapevine and cypresses. However, these pose only a very low allergenic risk.