THE CLIMATE OF JAPAN 35 



"toward the middle of June, and extending throngli the first half of 

 July. 



3. Barometric pressure and prevailing loinds. During the cold 

 «!eason the barometer stands highest over North China and Eastern 

 Siberia and lowest in the Pacific to the south of the Aleutian Islands, 

 the isobaric lines running from the northeast to the southwest almost 

 parallel to the back-bone of this island. But during the warm season 

 the barometer stands highest over the Pacific to the east of Eastern 

 Japan and lowest over the Continent. In the following table are 

 given average barometric pressures reduced to sea-level at the princip.al 

 places in Japan and the Continent : — 



Table I. Average barometric pressure at sea-level (in m.m.) 

 (See p. 36.) 



As described in the introductory paragraph, the direction of the 

 prevailing winds changes about every half year. The winter monsoon 

 bursts forth at the begiuning of October and continues to prevail till 

 the end of February. The summer monsoon sets in at the end of 

 April and continues till the beginning of September. In April and 

 September the wind is mostly variable. 



Table II. Prevailing winds. (See p. 37.) 



In winter the monsoon blows very strong aiid continues for many 

 da}'S together. In general the monsoon develops strongly when cy- 

 clones from the Continent pass over the Japan Sea, increasing in 

 intensity in the vicinity of the southern Kuriles. As a rule the vvdnd 

 is stronger in the daytime than at night, and often a calm prevails 

 in the night time. On the coast of the Japan Sea, snowstorms eccur 

 which make communication by shi])S very hard. Sometimes the ferry 

 services between Moji and Shimonoseki, and in the Korea straits 

 become temporarily suspended. On the Pacific coast the wind blows 

 also very strong, but is not accompanied by rain or snow. Fine 

 weather with cold northwesterly winds continues for many days. 



In summer the monsoon is, as we have already remarked, not 

 strong, and is intermittent. In sultry summer days it is refreshing 

 to bathe in the cool air from the Pacific. In the Inland sea district 

 the land and sea breezes develop remarkably. During the evening 

 calm, the air is so still that the leaves of tiny grasses scarcely quiver. 

 It becomes sultry and oj)pressive. But about 9 or 10 o'clock in the 

 evening a land breeze begins to set in and brin2;s cool air. 



