What are the 24 solar terms?

Twenty-four solar terms are the product of our ancestors' long-term production practice, which summarizes the relationship between astronomy, meteorology and agriculture, reflects the changes of seasons, cold and heat, and weather, and is the crystallization of the wisdom of our working people.

The earth goes around the sun once a year (365 days, 5: 48: 46). From the earth, we see the sun moving in the sky once a year, and the route of this movement is called the ecliptic. The position of the sun on the ecliptic is measured by the ecliptic.

At the vernal equinox and autumnal equinox, the ecliptic intersects the equatorial plane. At this time, the ecliptic is 0 degrees and 180 degrees respectively, and the sun shines directly on the equator, and day and night are equal.

On the summer solstice, the direct sunlight is 23.5 degrees north latitude and 90 degrees yellow longitude, which is the longest day in the northern hemisphere.

On the solstice in winter, the direct sunlight is 23.5 degrees south latitude and 270 degrees yellow longitude, and the daytime in the northern hemisphere is the shortest.

The vernal equinox and autumnal equinox are in the middle of spring and autumn, and the summer solstice and winter solstice are in the middle of summer and winter. In this way, a year can be divided into four sections: vernal equinox, summer solstice, autumn equinox and winter solstice. If each segment is divided into six segments, the sun runs 15 degrees on the ecliptic, and each segment is about 15 days, which can be divided into 24 segments throughout the year. According to the lunar calendar, the sun is a solar term every 15 degrees from 0 degrees on the ecliptic, and it is * * all year round.

Looking at the relationship between solar terms and astronomy, meteorology and farming season, there are eight seasons: beginning of spring, Spring Equinox, Long Summer, Summer Solstice, beginning of autumn, Autumn Equinox, beginning of winter and Winter Solstice.

There are five kinds of temperature changes: slight summer heat, great summer heat, summer heat, slight cold and severe cold.

There are seven weather phenomena: rain, Grain Rain, white dew, cold dew, first frost, light snow and heavy snow.

There are four kinds of phenology: Jing Zhe, Qing Ming, Xiao Man and Mangzi.

Because the twenty-four solar terms are based on some latitudes where the sun shines directly on the earth, they belong to the solar calendar, and each solar term basically corresponds to a certain date in the solar calendar. As follows:

Slight cold 65438+1October 5th or 6th-the climate is already cold, severe cold 65438+1October 20th or 2 1 day-February 3rd or 4th, the coldest season in beginning of spring-beginning of spring, that is to say, February1. Divide day and night equally. Qingming on April 4th or 5th-the temperature is warm and the weather is fine. April 6 19 or grain rain 20-the rainfall increases, which is beneficial to grain growth. On May 5th or 6th-May 20th or 2 1 long summer in the long summer, summer crops such as wheat are gradually full. Wheat and other crops with awns ripen on June 2 1 or 22-summer comes, with the longest day and the shortest night. July 6 or 7-just around the first summer, the climate began to get hot. July 22nd or 23rd-August 7th or 8th is the hottest season in beginning of autumn-autumn begins and the temperature drops gradually. August 22nd or 23rd. It means that the heat is about to pass. On September 7 and 8, when the weather is cold at night, the water vapor in the air often condenses into dew. On September 22 or 23, in the middle of autumn, the cold dew is equally divided day and night. 1On October 7th and 8th, the temperature dropped significantly. The dew is very cold at night, and the first frost is 65438+1October 23rd or 24th-beginning of winter begins to frost165438+1October 7th or 8th-light snow begins in winter165438+1October 20th.