Pollen is an important source of allergens in the natural environment, and the cause of the appearance of symptoms of allergic disease in hypersensitive individuals. In our laboratory, we monitor 60 types of pollen of various allergenic potential, and publish the results of measurements from different phytogeographical areas in Slovenia. Data on daily concentrations, together with many years of experience, are the basis for making short-term forecasts about pollen air pollution.

Pollen calendar in Slovenian language is available here.

Pollen forecast

11–18 March 2026

Alder pollen season is exceptionally intense this year; the first pollen load peak has already passed, but high daily concentrations are still possible. In lowland areas, the hazel pollen season is coming to an end, although some grains are still present in the air. People allergic to birch pollen may already develop allergic symptoms during this period due to cross-reactivity with hazel and alder. The development of birch catkins is progressing. Toward the end of next week, birches at warm sites, especially in urban areas, may already release the first individual pollen grains.

The ash pollen season is in full swing, with moderate to high pollen loads expected. Ash pollen may trigger allergy symptoms in individuals sensitised to olive allergens. The insect-pollinated forsythia, which is also related to these species, releases noticeable amounts of pollen only in the immediate proximity of shrubs; pollen can be brought indoors with spring bouquets. High concentrations of cypress/yew pollen and other low-allergenic species such as elm, poplar, willow and maple will be present in the air.

In the coastal region, the main allergens are cypress and ash pollen, with high pollen loads expected. Poplar, elm, willow and maple pollen will also be present. Hazel and alder pollen will still occur occasionally, with concentrations depending on transport from inland areas. The first hornbeam pollen grains have also been recorded.

Write to pelodinfo@nlzoh.si for more information.