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 forecast

6 – 13 May 2026

In the lowlands, the main grass pollen season is underway, and in dry weather pollen loads may reach high values. Plantain and dock/sorrel are also releasing pollen.

The birch season is coming to an end, although some pollen grains may still be present in the air. Pollen levels of hop-hornbeam, beech, and oak have also decreased but may still reach moderate to high concentrations. The ash season continues with manna ash, a common tree species in the warmer western parts of Slovenia. The plane tree season has ended. Pollen from cypress/yew family, walnut family, maple, elder, and locally horse chestnut will also be present. This year, conifers (spruce, pine) are flowering intensely, producing most of the yellow deposits seen on surfaces.

In the coastal region, grass pollen levels will be moderate to high. Oak pollen levels remain high, while individual birch grains are recorded only occasionally. The manna ash season is ongoing, with allergens related to olive pollen; their seasons may overlap briefly in mid-May. The air will also contain pollen from plantain, dock/sorrel, pellitory, cypress family plants, elder, hop-hornbeam, beech, and larger quantities of conifer pollen (pine, spruce).

Write to pelodinfo@nlzoh.si for more information.

Weekly Pollen report

Click here to visit the weekly pollen report.

Pollen calendar