In the present study, the daily, annual and seasonal variations of the electric field in Athens-Greece, for all weather as well as for fair weather conditions, for the 16-years period 1965–1980 were examined. The daily variation of the electric field follows a double oscillation. A Fourier analysis was also used for the study of its diurnal variation. The results of the Man-Kendall test showed that the electric field at National Observatory of Athens (NOA), during the 16-years period, is essentially constant. In addition, the influence of the air pollution due to smoke and of wind speed on electric field was examined. It was deduced that an increase of air pollution results in an increase of electric field, while the electric field decreases as the wind speed increases.