Abstract
Through an investigation of various historical records on climate written from the beginning of the XVII to the end of the XIX century, it is tried to connect the climatic change in the recent instrumental observation age to that of the historical times in Japan. It is concluded that the J apanese climate passed through a “little ice age” around 1750 to 1850. The mean January air temperature in the first half of the XIX century and the mean July air temperature from 1751 to 1850 are estimated as 1°-2°C lower than the present normal and the summer climate is concluded to have been pluvial, judging from the frequency of flood occurrences and their unprecedented scale. On the basis of the data of recent meteorological observations, it is concluded that the “little ice age” was caused by the weakening of the subtropical high and the southward retreat of the climatic zone.In this paper, the patterns in the Northern
