Japan Weather: June Rainfall
The Rainy Season 梅雨
The rainy or monsoon season in Japan (tsuyu) - usually occurs in June and July for a period of about 6 weeks and is marked by high humidity and heavy rainfall. Though no obstacle to travel, waterproof clothing and an umbrella are a good idea. The monsoon is less severe in the north of the country and does not affect Japan's northern-most island of Hokkaido at all.
To protect housing and farmland from the effects of heavy monsoon and typhoon rain, most of Japan's rivers have had their banks concreted over. Flash floods do still occur regularly particularly during the typhoon season, which is usually in September. Kyushu and the Kii Peninsula including the Prefectures of Wakayama and Mie have known some devastating recent floods with people and property washed away or destroyed in mudslides.
One attractive way of funneling large amounts of water from the roofs of traditional Japanese building and temples and shrines to the ground is the use of rain chains or kusari-doi.