Back to glossary

Solar Term · Shuāng Jiàng

Frost's Descent霜降

The instant the sun reaches 210° of ecliptic longitude — the last mid-month term of autumn, and it moves no pillar.

Solar longitude210°
Term type氣 — mid-month, opens nothing
Month branch
Typical dates23–24 October
Also seen asFrost Descends · Shuangjiang
This is a 氣 (mid-month term), not a 節. It marks the season's midpoint but changes no pillar — the month branch it falls inside was already opened by the 節 before it. Only the twelve 節 move the four-pillar chart.

01Overview

Frost's Descent (霜降, Shuāng Jiàng) is the eighteenth of the twenty-four solar terms and the final 氣 of the autumn season, sitting at the midpoint of the 戌 month that Cold Dew opened two weeks earlier. It is an astronomical instant: the moment the sun reaches 210° of ecliptic longitude, landing on 23 or 24 October depending on the year.

The name is literal rather than symbolic: this is traditionally the point in the year where frost starts forming in earnest across much of the temperate northern hemisphere, the visible marker that autumn's mild stretch is over.

02What it marks

Astronomically it sits between Cold Dew and Beginning of Winter, the last stop before the cross-quarter term that opens winter's first month. In the agricultural calendar it is read as the final call for the autumn harvest and the point where preparation for the cold months — storing, insulating, closing off — properly begins.

03In a BaZi chart

Frost's Descent is a 氣 — a mid-month term — so unlike Cold Dew before it, it changes no pillar. This site's engine confirms the general rule across a full year's scan: the twelve month pillar switches in 2026 land only on the twelve 節, and this term contributes none of them.

A birth at this instant still carries the 戌 month pillar that Cold Dew opened, exactly as a birth the day before or the day after would. The term marks a position in the sky and in the season, not a new boundary in the chart.

04Reading this descriptively

Frost's Descent marks the sky, naming the point where the season's dew turns to frost, and it moves none of the four pillars.

Stay in the loop

Reading more rooms?

We add palace, star, and advanced-concept pages every few weeks. Subscribe to the free Substack to know when the next batch ships.

Subscribe on Substack