Monthly sunshine durations were significantly above normal in northern, eastern and western Japan, because the regions were frequently covered with high pressure systems. In particular, northern Japan and the Sea of Japan side from eastern to western Japan experienced record-long monthly sunshine durations for May since 1946.
Monthly mean temperatures were also significantly above normal in northern, eastern and western Japan, with the highest for May since 1946 recorded in northern Japan due to the warm westerly wind and much sunshine duration.
Monthly precipitation amounts for the most part from northern to western Japan were below normal.
Cloudy and rainy days were dominant in Okinawa/Amami due to the Baiu-front and moist air flow.