Abstract
In this paper some relations between thunderstorm frequency and Baiu in Japan are treated statistically for the period ranging from 1925 to 1930. In the frequency curves of thunderstorms experienced at various places of this country, the remarkable abnormities occur in June or July covering about half a month. This fact indicates us that in such a time-interval the occurence of thermal thunderstorm is interrupted by some agency of heat type. The present authors wish to interpret is as the climatic effect of the rainy season or Baiu in Japan.
