Forecast

Issued 19th of January 2021

Situation and medium-term forecast

The Spaeth’s alder bloom ceases!

The majority of the Spaeth’s alders have emptied their catkins. This tree is a non-native species in Austria. It is only found cultivated in parks or as ornamental trees. Susceptible pollen allergy sufferers may still experience allergenic burden in close vicinity to such trees. The for this week forecasted rain and snowfalls will wash away already settled alder pollen.

Note: The immune system of a pollen allergy sufferer may be more susceptible at the start of the pollen season. Birch pollen allergy sufferers may be potentially concerned by the Spaeth’s alder’s pollination due to cross-reaction.

Currently, the catkins of native hazel and alder have not reached readiness to flower. At the end of January, the early bloomers' first low pollen burden has to be expected.

The forecasted start date of the hazel and alder pollen season is calculated based on forecast models. Due to the uncertainty of long-term temperature forecasts, hazel and alder’s actual flowering start can still vary. The predictions become more accurate as the season approaches.

We expect the readiness to flower for alder and hazel in	on
Vienna	30.01.2021
Eisenstadt	04.02.2021
St. Pölten	04.02.2021
Linz	09.02.2021
Salzburg	03.02.2021
Innsbruck	15.02.2021
Bregenz	08.02.2021
Graz	12.02.2021
Klagenfurt	28.02.2021
Bolzano	03.02.2021
Munich	12.02.2021

Forecast from 19.01.2021
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. Start of flowering is not to be equated with the beginning of the pollen season. When the start of flowering is achieved, the majority of the plants have the potential to release pollen, but only when weather conditions are favourable.