The 24 solar terms (èr shí sì jié qì 二十四节气) originated from the Reaches of Yellow River (huáng hé liú yù 黄河流域). As early as in the Spring and Autumn Period (chūn qiū shí qī 春秋时期), four solar terms were established by our ancestors, which are Spring, Summer, Autumn and Winter. Based on the practical needs of agriculture, Chinese people initiated the 24 solar terms towards the end of the Warring States Period (zhàn guó shí qī 战国时期, 475 B.C. --- 221 B. C.) However, the names for these solar terms did not appear until the Western Han Dynasy (xī hàn 西汉, 206 B.C. – 24 A.D.)

The 24 solar terms were determined by the changes of the sun’s position in the zodiac all through the year. A complete circle of the changes was divided into 24 segments, and each segment is about half a month. In the lunar calendar, the date of each solar term is basically fixed, with minor changes within one or two days. As a reflection of the regularity of the changes of the climate in the areas of the middle and lower reaches of the Yellow River, the 24 solar terms are still being used by the farmers.

The following are the 24 solar terms:
　
      立春 (lì chūn) start of spring
      雨水 (yǔ shuǐ) rain water
　　惊蛰 (jīng zhé)awakening of insects
　　春分 (chūn fēn) vernal equinox
　　清明 (qīng míng) clear and bright
　　谷雨 (gǔ yǔ) grain rain
　　立夏 (lì xià) start of summer
　　小满 (xiǎo mǎn) grain full
　　芒种 (máng zhǒng) grain in ear

      夏至 (xià zhì) summer solstice
　　小暑 (xiǎo shǔ) minor heat
　　大暑 (dà shǔ) major heat
　　立秋 (lì qiū) start of autumn
　　处暑 (chù shǔ) limit of heat
　　白露 (bái lù) white dew
　　秋分 (qiū fēn) autumnal equinox
　　寒露 (hán lù)cold dew
　　霜降 (shuāng jiàng) frost descent
　　立冬 (lì dōng) start of winter
　　小雪 (xiǎo xuě) minor snow
　　大雪 (dà xuě) major snow
　　冬至 (dōng zhì) winter solstice
　　小寒 (xiǎo hán) minor cold
　　大寒 (dà hán) major cold

二十四节气
      二十四节气起源于黄河流域。远在春秋时代，就定出仲春、仲夏、仲秋和仲冬等四个节气。以后不断地改进与完善，到秦汉年间，二十四节气已完全确立。公元前104年，由邓平等制定的《太初历》，正式把二十四节气订于历法，明确了二十四节气的天文位置。
　　
　　太阳从黄经零度起，沿黄经每运行15度所经历的时日称为“一个节气”。每年运行360度，共经历24个节气，每月2个。其中，每月第一个节气为“节气”，即：立春、惊蛰、清明、立夏、芒种、小暑、立秋、白露、寒露、立冬、大雪和小寒等12个节气；每月的第二个节气为“中气”，即：雨水、春分、谷雨、小满、夏至、大暑、处暑、秋分、霜降、小雪、冬至和大寒等12个节气。“节气” 和“中气”交替出现，各历时15天，现在人们已经把“节气”和“中气”统称为“节气”。