That is almost ironical, for June is the month that Tsuyu, the Rainy Season, starts, in the Kansai and Tokyo usually around the 10th of the month. Because the rain falls while the Ume (plums) ripen, it is called Bai-u (Bai is another way to read the character for ume). Another word for these rains is Samidare or Satsuki-ame - literally "Fifth Month Rain," as in the old lunar calendar our June was more or less the Fifth Month. As during the long rains it can be dark even in daytime, one speaks about Satsuki-yami, "darkness of the rainy season."
Coolness (Suzushi) is important, and therefore fans (Uchiwa) and folding fans (Ogi) are taken out and used to cool oneself. For added coolness, people dress in a light Yukata. In traditional houses, in the daytime the sitting room is opened up on all sides by taking away shoji and fusuma and this is called Natsu-zashiki, "a room for summer." In Kyoto along the Kamo River appear Kawadoko (floors set up over the water) meant for Yuka-suzumi (enjoying the evening cool).
[Kawadoko (yuka) along the Kamo River, central Kyoto]
June is also the month for Rice Planting (Ta-ue), the transplanting of the young rice plants (called sanae or wakanae) by Sa-otome (young women doing the rice planting) from a nursery to the rice field. Several shrines celebrate "Rice Planting Festivals," as the Sumiyoshi Shrine in Osaka in June 14 and the Fushimi Inari Shrine in Kyoto on June 10. Aota is the name for the green rice fields, caressed by soft breezes.
The new bamboo shoots, which were so delicious only two months before, grow up into fresh green bamboo (Wakatake) and in the Kuramadera Temple on June 20, the Takekiri or Bamboo-cutting Festival is observed.
The Summer Solstice (Geshi) also falls in June, on or around the 22nd. It has the longest daytime and the shortest night time of the year and therefore around this day one speaks of mijika-yo, "short nights."
June is the season that Hotaru, Fireflies, appear - in the past they were hunted and put into cases to enjoy their mysteriously flitting lights. The Cuckoo (Kankodori) sings from the middle of summer until the end of autumn and in the mountains the mysterious Bupposo may be heard.
June is also the month to start enjoying Reishu, Cold Sake, preferably enjoyed from cut glass (Giyaman or Kiriko), which contributes to a feeling of coolness. A suitable sweet is Take-nagashi, a hollowed out piece of bamboo filled with Yokan and served cold. The fresh color of the bamboo enhances the overall feeling of coolness.
Ayu is the primary fresh water fish for summer - the fishing season opens on June 1. The ayu has a brilliantly shining body and its taste has a delicious fragrance. June vegetables are Nasu (eggplant) and Kyuri (cucumbers).
[Hydrangea in Fujinomori Shrine, Kyoto]
The flower of the rainy season is of course the Ajisai or Hydrangea (Hortensia), glowing in its soft blue or pink in a shaded spot. Several temples and shrines are famous for their hydrangea gardens: Mimurotoji in Uji, Yatadera in Nara and the Fujinomori Shrine in Kyoto. The Fujinomori Shrine also holds an Ajisai Matsuri on June 15.
At the end of the month, on June 30, before the greatest heat sets in, various shrines all over Japan hold Nagoshi no Harae (also called Oharae-shiki), where people pass through a large ring of miscanthus reed to be purified from spiritual defilement. Good places in Kyoto are the Kamigamo Shrine and the Kitano Tenmangu Shrine (both 30th). The Kuramazaki Shrine, also in Kyoto, holds this observance the whole month of June.
Japanese seasonal customs according to the months of the year: