The impact of global warming on the vegetation season in Poland in 1961-2020

This article provides an analysis of the variability of the vegetation period (VP) and of the intensive vegetation period (IVP) in Poland in the years 1961-2020. Using average monthly values of air temperature from 55 weather stations in Poland, the VP and IVP onset- and end-dates were determined. A substantial spatial variability was found in the timing of the onset and termination of the VP and IVP in Poland. A statistically significant trend towards a longer vegetation period was also observed. The considerable extension of the VP and IVP affects the environment and human activities.