The potential number of generations per year in Germany was estimated for present climatic conditions and future climate projections. For the present condition, the function for generation time was fitted to the mean monthly temperatures for Germany at a resolution of 2.5′ (WorldClim database ). We calculated the number of generations per day and the cumulative number of potential generations per year. For future climate projections, the monthly average maximum and a minimum temperature of the CCSM4 model with a low and high greenhouse gas scenario, RCP2.6 and RCP8.5, for the period 2041 to 2050 was used (WorldClim database). As a final result, the minimum and maximum numbers of potential generations in Germany were extracted from the parameterised layer. As examples, six points of occurrence in Germany for the Asian bush mosquito were taken from the literature [26, 29, 31, 44, 50] (Additional file 1: Table S4) and the numbers of potential generations were calculated for these locations.