Japan's tsuyu, or rainy season, generally lasts from early June through the middle of July. Tsuyu is written in the Japanese language by combining the character for "plum" on the left with the character for "rain" on the right, duet to the fact that this meteorological even takes place during the time when plums become ripe.
Tsuyu is caused by seasonal rain front that forms above Japan, between tropical and Siberian high-pressure zones. It impacts all of Japan except for Hokkaido, the northernmost island. Although it does not rain constantly or even every day during tusyu, rain can come at any time and falls much more frequently than during the rest of the year. Temperature can fluctuate widely during this time of year, and humidity is generally high, even when it doesn't rain. Despite the occasionally annoying nature of tsuyu, it is an important time for rice cultivation and also brings forth a number of beautiful flowers and plants.