During a period of five years, impulses of atmospherics have been recorded on the following frequency ranges: Range I, about 10 to 50 kc; range II, about 4 to 12 kc. Only such impulses are counted and recorded the amplitudes of which exceed the relatively high threshold value of the amplifier.Considering the monthly means of the impulse sum per hour, we note that each of these five years shows two maxima. The first maximum, appearing during the summer months (May to August), can be explained easily by the frequency of thunderstorms occurring in central Europe in summer. The second one, however, which appears in winter, is strange.An exact analysis of the large‐scale weather processes results in the following: In the fall, the thunderstorm frequency in central Europe and in the Mediterranean regions is lowered because of large anticyclones (Azores high). During the winter months, violent invasions of polar air‐masses into the Mediterranean basin take place. Thus, moist labile gradients are formed over the relatively warm sea‐water, which give rise to renewed thunderstorms. These large‐scale changes of air‐masses are the reason for the observed winte