A comprehensive investigation on the variation of the Covid-19 pandemic adequate reproduction number (R) in four critical European countries is provided in this study as a function of the variations related to the weather, mobility, government responses, and epidemiology. In this study, an open data set about the Covid-19 pandemic is used for the analysis. The data contains newly recorded components with different metrics since the appearance of the COVID19 pandemic. The aim is to investigate the impact of the weather, mobility, and government restriction on the R values and pandemic. The appropriate statistical analyses are used to reveal the association and the effect of the various attributes to the R. In addition, multiple predictive models were applied. The results show significant differences between studied countries and have different factors that influence the virus’s spread.