Uki, Tsuyu, and Akisame: Rainy Season in Japan
Spanning from May to July, “Tsuyu (梅雨)”, also called “Baiu (梅雨)”, is a cloudy and rainy season that can broadly be seen in East Asia including the southern part of China, South Korea, Taiwan, and Japan.
Tsuyu (梅雨) and Uki (雨季)
In Japan, almost all areas except for the northernmost island of Hokkaido experience that cloudy, rainy period.
Entering the rainy season is called “Tsuyuiri (梅雨入り) or “Nyubai (入梅)”, which, based on the official website of Japan Meteorological Agency, begins with the country’s southernmost prefecture Okinawa annually early in May.
On the other hand, finishing the season is “Tsuyuake (梅雨明け)”, also known as “Shutsubai (出梅)”, which ends with the northern Tohoku region annually around the end of July.
One theory holds that the reason why “Tsuyu (梅雨)” includes the word “Ume (梅)” in its name is that the plum fruit ripens during the rainy period, and as you can see from the other word included, “Ame (雨)” meaning “rain”, Tsuyu is an “Uki (雨季)”.
As “Uki (雨季)” literally means “rainy season” in Japanese, it represents long periods of rainfall, spanning usually over one month,
and the representative examples in Japan are Tsuyu and the Autumn Rain “Akisame (秋雨)” seen from late August through around October.