IS93 1903 I9\5 1923 1953 i943 



Fig. 4- — Secular variation of air 

 temperature and precipitation 

 during summer of Hushiki. 



The striking contrast between the features of secular variation of 

 summer and winter cKmate especially of air temperatures as above 

 mentioned is to be found not only at Hushiki, but also in almost all 

 the parts of Japan. I have calculated the correlation coefficient between 

 ten year means of summer temperatures (June, July, and August) and 

 that of winter (December, January, and February) at twenty places(^) 

 scattered on Kyushu, Shikoku, and the Japan Proper, as shown in Fig. 5 

 the value of the coefficient being r = — (0-61 i 0-06). 



Generally speaking, the climate of Japan has changed, increasing the 

 annual range of air temperatures — that is to say, growing gradually 

 colder in winter and gradually warmer in summer during the past fifty 

 years. ' 



(1) Kagoshima, Hukuoka, Hiroshima, Sakai, Kochi, Wakayama, Hikone, Tu, 

 Hamamatsu, Nagano, Choshi, Utsunomiya, Hukushima, Yamagata, Mij-ako, 

 Ilukui, Tsuruga, Hushiki, Niigata, Akita. 



112 



