Rainy Season (Tsuyu) in Japan
In early summer, most parts of Japan get visited by a rainy season, the so called tsuyu (or baiyu),
literally meaning "plum rain", because it coincides with the season of plums ripening.
The rainy season is caused by the collision of cold northerly and warm southerly air masses, which results in a relatively stable bad weather front over the Japanese archipelago for several weeks.
In most of Japan, the rainy season lasts from the beginning of June to mid July, while it affects the islands of Okinawa about one month earlier. Only Japan's northern most main island of Hokkaido gets barely affected by the rainy season.
During the rainy season it does not rain every day. In fact, Tokyo registers only an average of 12 rainy days in June, while 120 hours of sunshine are recorded. As for the amount of rainfall, it varies from days with intensive downpours to other days with occasional sprinkles.
Nevertheless, the rainy season is not the most suitable season for visiting Japan, even though it can have its advantages. For example, travel activity is rather low during June, which clears many popular outdoor attractions from the many visitors that are usually present.
Furthermore, some sights can be very attractive in rain, especially some temples, gardens and hot springs.