//. The Climate of Japan, 



with a note on the 



Meteorological Service in Japan. 

 By 



Takematsu Okada, D. Sc, 



Director of the Central Meteorolosrical Observatorv. 



The Climate of Japan. 



1. The character of the climate of Japan is, in the first place, 

 determined by the prevalence of the monsoons. Dm-ing the cold 

 season the air temperature in North China and Eastern Siberia falls 

 greatly below the average for the year owing to an excessive nocturnal 

 cooling. The so-called cold pole is formed near Werchoyansk. There 

 the mean monthly minimum temperature is below -60° in January. 

 Due to this intense coldness of the air, the barometric pressure rises 

 generally over these portions of the Asiatic continent, and there the 

 extra-tropical zone of high barometric pressure shifts northwards, 

 forming a grand anticyclonic area over Eastern Siberia with its centre 

 near Lake Baikal. From this high area cold air flows out clockwisely 

 all over the Far East. This is the well-known monsoon current in 

 winter seasons. In Japan proper the winter monsoon comes from 

 the northwest, but in the Riukiu islands it comes from the north. 

 In Formosa the prevailing wind is northeasterly. 



During the warm season the air temperature in North China and 

 Mongolia rises excessively owing to the intense insolation and the 

 arid condition of the soil in these districts. The area of high baro- 

 metric pressure which covered these districts disappears and an area of 

 low barometric pressure takes its place. At the same time the grand 

 anticyclone of the North Pacific becomes intensified, its western 

 margin approaching as far as our east coast. The air flows into this 



