On October 23 the old Japanese calendar turns to soko, written 霜降, frost descends. It is the eighteenth of the twenty-four sekki and the last one that belongs to autumn. Fifteen days later, on November 7, winter begins.

The name is a report, not a promise. In the north of Japan the first frost really does arrive in these weeks; in Tokyo it is still a month away. The calendar was written for the fields, and what it records is the moment the year stops ripening and starts to close.

This year the thermometer disagreed. In the week before soko began, Tokyo had a summer day, 27 degrees, and 29 forecast for the next. The air was dry, though, and the shade was comfortable, which is how a late heat in October feels different from August. The calendar is not wrong in a week like that. It is a reminder that the season is read from the land, not the forecast.

The three micro-seasons

Soko divides into three ko of about five days each.

First frost, October 23 to 27. The mornings have an edge. Gardeners cover what they can and harvest what they cannot. In the house it is the week the first blanket comes out.

Light rains sometimes fall, October 28 to November 1. Shigure, the brief cold showers of late autumn, which pass as quickly as they come. The sky is clear, then not, then clear. Umbrellas are carried and rarely opened.

Maple leaves and ivy turn yellow, November 2 to 6. Koyo, the colouring of the leaves, moves down from the mountains to the cities. In the capital the ginkgo turn first, and the maples follow into December.

What people did, and still do

Soko was the season for bringing in the last of the harvest and for preparing the ground to sleep. Rice straw was stacked; persimmons were peeled and hung in rows under the eaves to dry into hoshigaki, which takes about the length of the sekki. Radishes were pulled and pickled.

In the house, the seasonal exchange of clothes that began at the start of October, koromogae, is finished by now. Heaters are checked. The kotatsu, the low heated table, comes out of storage in the last days of soko in many homes, because the first evening it is wanted is the first evening of winter.

For a home outside Japan

The calendar does not require Japanese weather. It requires attention. For these fifteen days, three small things.

Cover something. A plant, a tap, a bicycle, a bed with one more layer. The first frost is the signal to protect what will not survive it, and most of what needs covering is already known.

Dry something. Soko is the drying season in the old calendar: persimmons, radishes, herbs, mushrooms. A string of sliced apples by a window, a bunch of thyme over the stove. The point is less the food than the habit of putting the year away.

Walk once under the turning trees. Koyo in Japan is an occasion, with viewing spots and crowds; it does not have to be. One walk in the third ko, on a street with a tree that is changing, is enough to have noticed.

Why it is the last season

Soko closes autumn because the calendar counts seasons by what the land is doing rather than by the thermometer. Harvest is in, the ground is cooling, the leaves are going. Winter, which begins with ritto on November 7, is not colder on its first day than soko was on its last; it is simply the point at which there is nothing left to gather. Knowing that changes how the fortnight feels. It is not the end of warmth, it is the end of the year’s work.

Reading the season

The old names ask one question each: is this happening where you are? Frost, passing rain, yellow leaves. Writing one line per ko, on the day it starts, is the whole practice of keeping the calendar, and soko is a good one to begin with, because its three signs are visible almost everywhere in the northern hemisphere.

The line for first frost might be “not yet, but the car windows were wet and cold.” The line for light rains might be “twice today, both over in ten minutes.” That is enough. By ritto, the beginning of winter, the year will feel properly ended, which is what soko is for.

A free three-month log. Let One Thing Age gives you three months to watch one object change, and a line a week to write down what you see. You get it by email, free. → Get the free log

Continue Reading

This article is part of a series exploring Japanese philosophy and intentional living:

• Twenty-Four Seasons: Changing One Thing Every Two Weeks
• The 72 Micro-Seasons of Japan: Every Date for 2027
• Koromogae: The Japanese Seasonal Wardrobe Change