Rittō: The First Day of Winter (Around November 7th)

What Is Ritto (the Start of Winter)?

The 24 solar terms divide the year by the sun's movement into 24 seasonal markers, and they long served as a guide for farm work. Ritto is the 19th of the 24 solar terms of the traditional East Asian calendar, and it can also refer to the period until the day before the next term, Shosetsu. It marks the day winter begins on the calendar. It is the day that contains the moment the sun reaches an ecliptic longitude of 225 degrees, which falls around November 7th or 8th each year; in 2026 it is November 7th. Together with the starts of spring, summer, and autumn, it is one of the four "shiritsu." The Edo-period almanac Koyomi Binran describes it as the time when "the air of winter begins to rise and things grow ever colder." It sits exactly halfway between the autumn equinox and the winter solstice, and from this day until the day before Risshun, the start of spring, is winter by the calendar.

The Weather Around Ritto and the 72 Micro-Seasons

The 72 micro-seasons divide each solar term into three phases of about five days each. In fact, across most of Japan except the north, the days around Ritto still feel like autumn, and the peak of the autumn leaves is yet to come. Even so, mornings and evenings grow colder, the sun sets earlier, and daylight keeps shortening toward the winter solstice (December 22nd in 2026).

• First phase (around Nov. 7):"Tsubaki hajimete hiraku" -- sasanqua camellias begin to bloom
• Second phase (around Nov. 12):"Chi hajimete kooru" -- the ground begins to freeze
• Third phase (around Nov. 17):"Kinsenka saku" -- narcissus flowers bloom. In the Chinese calendar the first and third phases read quite differently, with water beginning to freeze and pheasants turning into clams

The First Kogarashi and the Inoko Festival

The "Kogarashi ichigo," the first cold, dry wintry wind of the season, is a sign that the winter pressure pattern has set in. The Japan Meteorological Agency announces it for Tokyo and Osaka. For Tokyo, the guide is a north-northwesterly to northerly wind with a maximum speed of about 8 m/s or more between mid-October and the end of November, and it can come before or after Ritto. For Osaka, it is announced for a northerly wind between Soko (around October 23rd) and the winter solstice (around December 22nd). Mainly in western Japan, there is also the "Inoko" event on the first day of the boar in the old tenth month. One theory says the custom of eating mochi on this day in China entered court ritual in Japan, and in farming villages it doubled as a harvest celebration. Boars are prized for having many young, and some mochi are shaped to represent boar meat. People eat inoko mochi, praying for health and many descendants, and in some places children go around pounding the ground. It was also said that opening the kotatsu on this day would keep fire away.

Tips for Marking This Day

• Keep a lap blanket or a jacket at the office for the chilly mornings and evenings, and start preparing for winter
• Choose a warm soup or hot pot for lunch and enjoy the change of season. A steaming hot pot is a winter table staple
• Ritto is also "Arare and Senbei Day" (set in 1985 by the national rice cracker industry association) and "Cocoa Day" (set in 2016 by Morinaga). Use them as small talk over a warm drink
• On your way home, look up at the sky, notice how early the sun sets, and see whether sasanqua flowers are blooming. You can also look up your local sunset time on the National Astronomical Observatory's calendar calculator

Winter on the Calendar, a Guide for Daily Life

Ritto is a good cue to review heating, winter clothing, and your health before the cold sets in. Paying attention to the small changes of the 72 micro-seasons can reveal the changing season even on the way to work. Because the season advances differently by region, the gap between winter on the calendar and the actual cold can make good small talk.