The 24 Solar Terms

Written by Sally Guo Updated Sep. 20, 2022

The 24 Solar Terms were developed by farmers in ancient China through observation of the sun's annual motion.

These terms are used to mark the seasons, weather, and natural variations. The year is divided into twenty-four equal periods. This thus provides a time frame for farmers to plan crop production and farming as well as daily life and festivals.

Solar Terms are divided according to the sun's annual motion in the ecliptic plane (the Earth's orbit around the Sun). It is part of the traditional Chinese calendar zodiac.

The 24 Solar Terms were inscribed on the Representative List of the Intangible Cultural Heritage of Humanity by UNESCO in 2016.

24 Solar Terms 2022

Season	Solar Terms	Chinese	Date in 2022	Remark
Spring	Start of Spring	lì chūn 立春	Feb. 4	Beginning of Spring in Southern China.
	Rain Water	yǔ shuǐ 雨水	Feb. 19	Rainfall increases from then on.
	Awakening Insects	jīng zhé 惊蛰	Mar. 5	Hibernating insects start to awaken with spring thunder.
	Spring Equinox	chūn fēn 春分	Mar. 20	The mid-spring, day, and night are equally long.
	Pure Brightness	qīng míng 清明	Apr. 5	It is warm and bright (when not raining) vegetation turns green.
	Grain Rain	gǔ yǔ 谷雨	Apr. 20	Rainfall increases greatly and is helpful to grain.
Summer	Start of Summer	lì xià 立夏	May 5	Beginning of Summer in the South of China
	Grain Full	xiǎo mǎn 小满	May 21	The grain gets plump but is not yet ripe.
	Grain in Ear	máng zhòng 芒种	Jun. 6	Grain grows ripe and summer farming begins.
	Summer Solstice	xià zhì 夏至	Jun. 21	It is the longest day of the year in China.
	Slight Heat	xiǎo shǔ 小暑	Jul. 7	It is hot.
	Great Heat	dà shǔ 大暑	Jul. 23	The start of the hottest time of the year and when rainfall is the greatest.
Autumn	Start of Autumn	lì qiū 立秋	Aug. 7	Beginning of Autumn
	Limit of Heat	chù shǔ 处暑	Aug. 23	Marks the end of hot days.
	White Dew	bái lù 白露	Sep. 7	Temperatures begin to drop and it turns quite cool.
	Autumn Equinox	qiū fēn 秋分	Sep. 23	Mid-Autumn, the day and night are equally long.
	Cold Dew	hán lù 寒露	Oct. 8	Turns a bit cold.
	Frost's Descent	shuāng jiàng 霜降	Oct. 23	Turns colder and frost appears.
Winter	Start of Winter	lì dōng 立冬	Nov. 7	Beginning of Winter
	Light Snow	xiǎo xuě 小雪	Nov. 22	Starts to snow.
	Heavy Snow	dà xuě 大雪	Dec. 7	Snows heavily for the first time of the year.
	Winter Solstice	dōng zhì 冬至	Dec. 22	The shortest day of the year.
	Slight Cold	xiǎo hān 小寒	Jan. 5, 2023	Gets colder.
	Great Cold	dà hān 大寒	Jan. 20, 2023	The coldest time of the year.

Origin and History of the 24 Solar Terms

As early as the Spring and Autumn Period（770-476 BC), ancient Chinese ancestors established two major solar terms: Summer Solstice and Winter Solstice, meaning "Sun North Most" and "Sun South Most," respectively.

Near the end of the Warring States Period (475-221 BC), they distinguished the four seasons: Start of Spring (Spring Equinox); Start of Summer (Summer Solstice); Start of Autumn (Autumnal Equinox); Start of Winter (Winter Solstice).

Eight key solar terms were established according to the moving position of the sun and the moon in the beginning and middle of a month, and the climate and natural phenomena.

During the Western Han Dynasty (206 B.C.-24 A.D.), the twenty-four solar terms were completed and officially designated; most of them refer to the climate of Xi'an, the capital of the Han Dynasty.

The complete 24 solar terms are integrated into the Gregorian Calendar. And it continues to be used today.

Meaning of the 24 Solar Terms

24 Solar Terms reflect the seasonal characteristics of natural phenomena and agricultural production each year.

This illustrates the wisdom of the Chinese in dividing the seasons. They influence commerce and the livelihoods of the people. These livelihoods contribute to basic human necessities (housing, food, clothing, transport) and play an important role in daily life.

Seasonal Variations

The 24 solar terms take into account the longest and shortest days of the year, as well as the two days of the year when the length of the day is the same as the night.

The Start of Spring, the Start of Summer, the Start of Autumn, and the Start of Winter divide a year into four seasons.

Spring Equinox, Autumnal Equinox, Summer Solstice, and Winter Solstice reflect the turning point of the changes in altitude of the sun.

Climate Changes

Slight Heat, Great Heat, Limit of Heat, Slight Cold, and Great Cold make known the temperature variations in different periods of the year.

Rain Water, Grain Rain, Light Snow, and Heavy Snow indicate the time and intensity of rainfall and snowfall.

White Dew, Cold Dew, and Frost's Descent embody the course and degree of the gradual decrease of temperature.

Natural Phenology

Grain Full, Grain in Ear, Awakening Insects, and Pure Brightness reflect the natural phenology phenomenon (the study of the timing of the biological events in plants and animals).

Top 3 Popular Solar Terms

1. Start of Spring – Welcoming Spring

The Start of Spring is usually around February 3rd, 4th, or 5th during the period of Chinese New Year, also called Spring Festival, and marks the beginning of the spring season.

On this day, people from the south of China traditionally welcome spring by setting off firecrackers and eating Spring Rolls (Chun Juan or Chun Bing in Chinese), crisply fried pastry rolls filled with shredded pork, mushrooms, cabbage, and slightly crunchy bamboo shoots.

2. Pure Brightness – Remembering Ancestors

Pure Brightness is not only a solar term but also a traditional festival, Qingming Festival. It is also known as Tomb-Sweeping Day (清明节 qīng míng jié) and has been celebrated in China for centuries. The day is meant to commemorate and pay respect to a person's ancestor.

Qingming Festival can fall on any day between April 4th and April 5th. There are many classic ways Chinese people celebrate Qingming Festival:

Show respect by visiting the graves of ancestors to sweep, tidy up, and place fresh flowers on the graves. The most popular are chrysanthemums and lilies;
Take a walk outside and welcome spring while enjoying the fresh April air and first signs of spring greenery;
Eat Sweet Green Rice Balls are made from a mixture of glutinous rice flour and green plant juice. Then it is stuffed with sweetened bean paste;
Kite-flying with colored lanterns tied to the end of the kite. It is said that if you let go of the kite, it will ward off sickness and bring good fortune!

3. Winter Solstice – Ancestor Worship – and Family Reunions

Winter Solstice marks the first official day of winter. The solstice happens at the same time in every place on Earth. It's when the sun on the sky's dome reaches its farthest southward point for the year.

At this solstice, the Northern Hemisphere has its longest night and shortest day of the year.

Winter Solstice Festival (冬至 dōng zhì) also referred to as Winter Festival or Dongzhi Festival, is one of the most important festivals in China. It falls on December 21st or 22nd. The date is dependent upon the tilt of the Earth.

It's winter in the Northern Hemisphere when the South Pole tilts toward the Sun. The origins of Winter Solstice can be traced back to the Yin and Yang Philosophy of Balance and Harmony in the cosmos.

Traditionally, Winter Festival is a time for friends and extended families to socialize and enjoy delicious foods. The kinds of foods eaten during festivals vary from region to region.

Dumplings (饺子 jiǎo zi), sometimes dipped in a small bowl with a mixture of vinegar and soy sauce before being eaten, are a popular and essential food for many people in Northern China.

While in Southern China, it's customary for families to make and eat Tangyuan (汤圆 tāng yuán) during Winter Festival.

Tangyuan and JIaozi — Traditional Winter Solstice Food: Tangyuan and Jiaozi

In other regions of China, people eat hot foods to celebrate Winter Festival and to stay warm!

For example, Mutton Paomo (or mutton soup) is a popular food eaten in Xi'an, home to the Terracotta Army. It's a spicy soup made with slices of mutton and small peanut-sized hunks of unleavened flatbread, often eaten with noodles.