Autumn, also known as Fall in American English, is one of the four temperate [温带的] seasons. Outside the tropics, autumn marks the transition from summer to winter, in September (Northern Hemisphere) or March (Southern Hemisphere), when the duration of daylight becomes noticeably shorter and the temperature cools considerably. Day length decreases and night length increases as the season progresses until the Winter Solstice [冬至] in December (Northern Hemisphere) and June (Southern Hemisphere). One of its main features in temperate climates is the shedding of leaves from deciduous [落叶] trees. deciduous的反义词好记: evergreen

Thanksgiving is celebrated on the second Monday of October in Canada and on the fourth Thursday of November in the United States and around the same part of the year in other places. Halloween, 31 October, is in autumn in the northern hemisphere. Pumpkin pie is commonly served on and around Thanksgiving in North America.

Although colour change in leaves occurs wherever deciduous trees are found, coloured autumn foliage [叶子] is noted in various regions of the world: most of North America, Eastern Asia (including China, Korea, and Japan), Europe, southeast, south and part of the midwest of Brazil, the forest of Patagonia, eastern Australia and New Zealand's South Island. The Andean-Patagonian forests, also known as Subantarctic forests, spreads over steep elevations along a thin strip on both sides of the Andes [安第斯山], on southern South America.

According to the Chinese lunar calendar, the autumn season extends throughout the seventh, eighth, and ninth months. This makes the fifteenth day of the eighth lunar month the season's midpoint. From this point onward, the power of the sun begins to wane; the days grow shorter and cooler, and the nights grow longer. The Chinese celebrate the moon's birthday on this day, believing that it is the only night of the year when the moon is perfectly round. The Mid-Autumn Festival is therefore a double feast - a time for worshipping the moon goddess and for expressing gratitude for the harvest.

The Mid-Autumn Festival has been compared to the American Thanksgiving, and there are some similarities. Family reunions are common, with family members often travelling long distances to be together. They feast, exchange gifts, and eat Moon Cakes. Many of these reunions take place out-of-doors in the evening, where the size and brightness of the moon can be admired.

2016年11月30日，二十四节气被正式列入联合国教科文组织人类非物质文化遗产代表作名录。在国际气象界，二十四节气被誉为“中国的第五大发明”。The names of each of the twenty-four two-week periods sometimes correspond to seasonal festivals celebrated during the period. Beginning with the New Year, which takes place in late January or early February, these periods are known by the following names: Spring Begins (New Year and LI CH'UN), the Rain Water, the Excited Insects, the VERNAL EQUINOX, the Clear and Bright (CHING MING ), the Grain Rains, the Summer Begins, the Grain Fills [小满], the Grain in Ear [芒种], the SUMMER SOLSTICE (DOUBLE FIFTH), the Slight Heat, the Great Heat, the Autumn Begins, the Limit of Heat, the White Dew (MID-AUTUMN FESTIVAL), the AUTUMN EQUINOX, the Cold Dew, the Hoar Frost Descends, the Winter Begins, the Little Snow, the Heavy Snow, the WINTER SOLSTICE, the Little Cold, and the Great Cold.

《月令七十二候集解》：“五月节，谓有芒之种谷可稼种矣。”意指大麦、小麦等有芒作物种子已经成熟，抢收十分急迫。晚谷、黍、稷等夏播作物也正是播种最忙的季节，故又称“芒种”。 [牛津词典] ear: (麦子等)麦穗suì