Hazel is an important source of tree pollen allergens, which are responsible for inhalant allergy symptoms in early spring. The aim of the study was to compare Corylus pollen season in 2022 in 12 cities located in different regions of Poland: Bialystok, Bydgoszcz, Cracow, Kielce, Lublin, Olsztyn, Piotrkow Trybunalski, Sosnowiec, Szczecin, Warsaw, Wroclaw and Zielona Gora. The measurements were conducted using a Burkard- type volumetric sampler, operating in continuous volumetric mode. The following parameters were analyzed: pollen season duration, peak value and peak date, seasonal pollen integral and number of days with concentration exceeding the threshold values triggering allergy symptoms in sensitized individuals. The hazel pollen season in 2022 began in January and the first decade of February. The earliest it began in the western regions, and the latest in eastern Poland. In most cities, maximum daily pollen concentrations were registered between February 5th and 24th. The 2022 hazel pollen season, compared to the 2021 season, was characterized by higher maximum daily pollen concentrations, higher seasonal pollen integrals (SPI) and higher number of days exceeding the threshold value for triggering allergy symptoms in most of the analyzed cities. The highest peak was recorded in Lublin (290 grains/m3) and the highest annual sum (SPI) in Cracow (2071). In 2022 the highest risk of allergy symptoms to hazel pollen allergens in sensitized individuals was found in Lublin, Cracow, Kielce and Sosnowiec