From Dec 17, 2026 to Dec 21, 2026, the corresponding solar term in the Nijūshi Sekki (24 solar terms) is 大雪(Taisetsu), and the corresponding microseason in the Shichijūni Kō (72 microseasons) is 鱖魚群(Sake no uo muragaru).

What Is “Sake no uo muragaru” (鱖魚群)?

"Sake no Uo Muragaru" (鱖魚群, Salmon Gather and Swim Upstream) is one of the Shichijūni Kō (72 microseasons), Japan's traditional system of seasonal divisions. It is the final microseason of Taisetsu (大雪, Major Snow), one of the Nijūshi Sekki (24 solar terms), and typically falls between December 17 and December 21, lasting about five days. The term "sake no uo" (鱖魚) refers to salmon, while "muragaru" (群) means "to gather in groups" or "to form a shoal." Thus, "Sake no Uo Muragaru" describes the sight of salmon gathering and swimming upstream into rivers to spawn. For centuries, the image of salmon powerfully making their way through the clear rivers of winter has inspired the Japanese people with a sense of life's resilience and the mysteries of nature. During this period, salmon can be seen migrating upstream in rivers across Japan. In regions such as Hokkaidō and Tōhoku, salmon fishing has long been an important seasonal tradition. Salmon are also known as "Chiaki-sake" (千秋鮭), or "thousand-autumn salmon," and have traditionally been regarded as auspicious fish symbolizing abundance and prosperity. Customs such as eating salmon at the end of the year and giving salmon as a year-end gift are rooted in the deep connection between this season and the fish itself. The Shichijūni Kō (72 microseasons) is a uniquely Japanese calendar that divides the year into 72 periods, each delicately capturing seasonal changes, natural phenomena, and the activities of plants and animals. "Sake no Uo Muragaru" is the second-to-last microseason of the year, quietly signaling the approach of year's end through the rhythms of the natural world. Amid the bustle of December, taking a moment to reflect on salmon swimming upstream can offer a deeper appreciation of Japan's rich natural environment and the refined seasonal awareness cherished by generations past.

List of Japan’s 72 Microseasons