The paper presents the characteristics of frosts occurrence at the Ecological Station in Jeziory (Wielkopolski National Park) in years 2001–2016. The frequency of occurrence of frosts in the spring and autumn, their intensity and duration of the frost-free period were analyzed. A tendency was observed to extend the frost-free period, which results primarily from the early disappearance of spring frosts. The slight frosts occurred the most often in Jeziory. The most severe frosts occurred occasionally due to the specific location of the station on the forest clearing.