岡山市の気温・降水量の経年変化

In this paper, secular changes of air temperature and the amount of precipitation in Okayama city are discussed using observed values at Okayama meteorologiccal station. Special reference is made to 1993 and 1994 in which peculiar changes occurred. The results obtained are summarized as follows: (1) The increasing rate of the annual mean air temperature at Okayama city is 0.85℃/100y. This value is nearly equal to the average of Japan; 0.87℃/100y. (2) The increasing rate indicates seasonal changes, and the rate is high especially in April and May. (3) The rapid increase of the air temperature in the 1980s is due to removal of Okayama meteorological station from the edge of town to the center. (4) The annual mean air temperature in 1994 is 16.9℃, and the monthly mean temperature for July and August are 29.8 and 29.6℃ respectively. These values are new records at the Okayama station. (5) The air temperature in July and August, 1993 are higher than in 1980 when it was much colder in the summer. (6) The amount of precipitation does not show any secular changes.