The aim of the study was to compare the hazel pollen season in 2016 in Zielona Gora, Opole, Wroclaw, Sosnowiec, Cracow, Lublin, and Guciow (Roztocze National Park). Due to the mild winter, the hazel pollen season in Zielona Gora and Opole began very early, i.e. in the third decade of December 2015. In the other cities, the onset of the pollen season was noted between 30th January and 7th February. In a majority of the cities, the maximum daily pollen concentrations were recorded in the period between 7th and 10th February. The highest seasonal peak was reported from Lublin and the lowest – in Guciow and Wroclaw. The highest risk of allergy related to the persistence of high concentrations of airborne hazel pollen was noted for Zielona Gora, Lublin, and Cracow.