Frost’s Descent

Meaning

Frost’s Descent, Shuangjiang, is the eighteenth of the twenty-four solar terms: the Sun at 210°, about 23 October. The dew of the earlier autumn terms now freezes into frost on clear nights in the north; the trees turn red and gold and begin to shed their leaves, and the cold of winter can be felt coming.

It is the last term of autumn, a principal term in the middle of the Dog month, and it names the ninth lunar month. Fifteen days after it, Lidong opens the winter.

Its three pentads close the season: the jackal lays out its prey before the winter, the plants turn yellow and let their leaves fall, and the creatures that will sleep through winter lie down in their dens. In the five phases the Metal of autumn is giving way to the Water of winter, and the Dog month’s branch, Xu, an Earth branch, holds the passage.

In practice

• In BaZi nothing turns at Frost’s Descent: the month pillar stays the Dog month’s until Lidong. A birth near it is no nearer a change of pillar.
• In the Chinese calendar it names the ninth lunar month.
• The Calendar marks it on its day, with the Sun at 0° Scorpio, as the middle of the Dog month; astrology marks the same instant as the Sun’s entry into Scorpio.
• In the zodiac and Feng Shui the month animal and the month’s star are those of the Dog month, from Hanlu to Lidong.

Across traditions

• In Western astrology the Sun enters Scorpio at this very moment, the sign of the year’s deepening and of what goes underground, as the Chinese calendar names its frost.
• In Japan sōkō is the time when the autumn leaves, kōyō, begin to colour the mountains; in Korea the term is sanggang, in Vietnam sương giáng.
• In the Celtic year the weeks before Samhain, on 1 November, are those of the last harvests and of bringing the herds in, the threshold of winter that Frost’s Descent also marks.

Origin and history

The Monthly Ordinances of the Book of Rites describe the month of the first frost: the jackal’s offering, the falling leaves, the creatures going to ground, and the ruler’s orders to finish the harvest and to prepare for the cold. The Huainanzi, in 139 BC, sets the term among the twenty-four, and the old seasonal instructions give its pentads.

Persimmons are the fruit of this term: ripened by the first frosts, they are eaten fresh or hung to dry in strings under the eaves, and an old saying holds that one should eat them at Shuangjiang. It is also the season of chrysanthemum viewing in the gardens, and of the last outings before the cold.

How Ulune calculates it

Ulune takes Frost’s Descent as the instant the Sun’s apparent longitude reaches 210°, from its table of the solar terms computed with the Swiss Ephemeris for 1800 to 2200. As a principal term it changes no pillar; the Calendar shows it on the reader’s own date. In 2026 it falls on 23 October at 09:37 UT.

Correspondences