On September 23rd this year, it is the 16th solar term of the 24 solar terms, known as the Autumnal Equinox (Qiū Fēn). It is also the fourth solar term of the autumn season. During the Autumnal Equinox, the sun shines almost directly onto the Earth's equator, making day and night almost equal in length worldwide. The Autumnal Equinox (秋分), where "分" (Fēn) means "divide" or "split," signifies not only the equal division of day and night but also symbolizes the division of the autumn season. After the Autumnal Equinox, the position of direct sunlight shifts southward, resulting in shorter days and longer nights in the Northern Hemisphere. This leads to an increased temperature difference between day and night, with temperatures gradually decreasing day by day.
Traditionally, the Autumnal Equinox was celebrated as a "Moon-worshiping Festival (祭月节)", and the Mid-Autumn Festival evolved from the "festival of worshiping the moon on autumn eve". On June 21, 2018, the State Council of the People's Republic of China approved the establishment of the "Chinese Farmers' Harvest Festival," designating the Autumnal Equinox as a day to celebrate agricultural abundance.
Meteorological Changes
During the Autumnal Equinox, vast regions in China north of the Yangtze River, including its basin, transition into the autumn season divided by "pentad average temper", with daily average temperature dropping below 22°C. Cold air masses in the northern regions gain some influence. Most areas have just concluded the rainy season, and the weather becomes cool and pleasant with clear skies. The position of direct sunlight shifts towards the Southern Hemisphere after the Autumnal Equinox, the Northern Hemisphere receives less solar radiation. Simultaneously, the Earth's surface loses heat more rapidly, leading to a noticeable acceleration in temperature decline. There are sayings in agriculture: "A autumn rain brings a cold night," and "White dew brings a cold night."
Agricultural Activities
The characteristic of rapid cooling in autumn makes the busy schedule of "Three Autumn Terms Health Preservation" for autumn harvest, autumn cultivation, and autumn planting particularly tense. The Autumn Equinox is the prime time to harvest, as cotton opens and tobacco leaves turn from green to yellow. In North China, winter wheat sowing has already begun, while in the Yangtze River Basin and the southern regions, farmers are busy with late rice harvesting, striving to plow and prepare the land for rapeseed planting. Dry spells or continuous overcast and rainy weather during the Autumnal Equinox season are significant adverse factors affecting the normal progress of the "Three Autumn Terms". Especially, continuous rainy weather can cause collapsed, rotted, or germinated crops, resulting in severe losses. The key to success in the "Three Autumn Terms" lies in acting "early." Timely harvest of autumn crops can protect them from early frosts and continuous rainy weather. Early sowing of winter crops can make full use of the pre-winter heat resources, ensuring the safe overwintering of robust seedlings and laying a solid foundation for a bountiful harvest next year.
Traditional Customs
Eating Autumn Vegetables: In the Lingnan region, the Hakka people have a custom of eating autumn vegetables. The autumn vegetable, known as "Qiu Bi Hao," is a type of wild amaranth. On the day of the Autumnal Equinox, the whole village goes out to harvest autumn vegetables. The preparation method is similar to spring soup, with fish slices added to make autumn soup.
Flying Kites: The Autumnal Equinox is a good time for Hakka children to fly kites. Especially on the day of the Autumnal Equinox, even adults participate. There are various types of kites, including wang-shaped kites (a kite shaped like a Chinese characters "wang"), carp-shaped kites, moth-shaped kites, centipede-shaped kites, and crescent-shaped kites. The larger ones are two meters tall, and the smaller ones are two or three feet tall.
Moon Worship: The Autumnal Equinox was once a traditional "Moon-worshiping Festival". There used to be a saying, "Spring worships the sun and autumn worships the moon." The current Mid-Autumn Festival evolved from this traditional festival. According to research, the original "Moon-worshiping Festival" was set on the day of the Autumnal Equinox. However, because the day of the Autumnal Equinox falls on different dates in the eighth month of the lunar calendar each year, it doesn't always coincide with a full moon. Celebrating the moon without its fullness would be less splendid. Therefore, the "Moon-worshiping Festival" was later moved to the Mid-Autumn.
Balancing Eggs: Every year on the day of the Autumnal Equinox, millions of people around the world participate in the "balancing eggs" experiment. This activity, known as a "Chinese custom," has become a "worldwide game," though its origins remain uncertain. Nonetheless, its rules are simple and entertaining: select a fresh chicken egg that's just been laid four or five days ago, and gently balance it upright on a table. While many fail, there are also many successes. The Autumnal Equinox has become the prime time for this egg-balancing game, hence the saying, "With the arrival of the Autumnal Equinox, the eggs are perky."
Sending Autumn Oxen: During the Autumnal Equinox, people traditionally go from house to house to deliver autumn oxen illustrations. This involves printing the lunar calendar's 24 solar terms on red or yellow paper, along with an image of a farmer tilling the fields, known as the "Autumn Oxen Illustration."
Health and Lifestyle
Autumn is a season of dryness, and the predominant external pathogenic factor is dryness. Prior to the Autumnal Equinox, there's still lingering heat from summer, leading to a prevalence of warm-dryness (温燥). After the Autumnal Equinox, autumn winds start to blow, gradually lowering temperatures and increasing coldness. As a result, cold-dryness (凉燥) becomes more prominent. To prevent dryness, it's crucial to engage in regular exercise, enhance physical fitness, and boost resistance to diseases. Autumn exercise focuses on benefiting the lungs and moistening dryness, such as practicing breathing exercises and performing mouth and throat exercises to generate moisture. In terms of diet, it's advisable to drink plenty of water and consume foods that are clear and moist, such as Chinese yam, lotus root, sesame, walnut, glutinous rice, honey, dairy products, and pear. These can nourish yin, moisten the lungs, and generate fluids.
