Ionospheric monthly-median values of the F2 and E layer critical frequencies from 24 mid-latitude European stations are fitted to a second degree polynomial and their correlation is discussed. The resulting model is used to predict monthly-median f0F2 values for different ionospheric stations and for high, medium and low ionospheric activity. Finally, a potential application of the single station model developed for Slough to mapping the F2-layer critical frequency is investigated. Thus prediction of the monthly median f0F2 values for eight mid-latitude European stations is attempted using the single-station model of Slough and the corresponding F0E values of the station under investigation. The f0F2 values obtained are reasonably accurate. The main advantage of this method is its simplicity and the restricted number of parameters used.