Summary of climatic characteristics of solar terms in autumn equinox

Climatic characteristics of autumnal equinox: cold air moves southward, and geothermal energy is largely lost. The average daily temperature in autumn is below 22℃.

1, cold air heading south

On the day of the autumnal equinox, the sun is located at longitude 180 degrees, and the sunlight is almost direct to the equator, and day and night are almost equal. At this time, the temperature in the southern region generally dropped below 22℃, and it entered a cool autumn. "An autumn rain and a cold". The cold air from the south meets the warm and humid air that gradually decays, which leads to repeated rainfall and the temperature drops again and again.

2, the ground heat loss is more.

After the autumnal equinox, the direct sunlight moved to the southern hemisphere, and the northern hemisphere got less and less solar radiation, but the ground lost more heat and the temperature dropped significantly. Agricultural proverbs say: "An autumn rain is a cold", "The white dew is divided into autumn nights, and one night is cold". "In August, the wild goose gate opens, and the foot of the wild goose is frosty." It is not surprising that the temperature in Northeast China drops early and frost appears at the autumnal equinox.

3. The average daily temperature in autumn is lower than 22℃

At the autumnal equinox, the Yangtze River basin and its vast northern area have entered autumn, and the daily average temperature has dropped below 22℃. Air conditioning in the north began to have a certain impact. In most areas, the rainy season has just ended, with a cool breeze blowing gently, the sky is high and the clouds are light in Wan Liqing, the air is crisp in autumn, the sweet-scented osmanthus is fragrant, the crab is fat and the chrysanthemum is yellow, and the autumn equinox is a beautiful and pleasant season.

Related introduction of autumnal equinox

The autumnal equinox belongs to a transitional season. As soon as this solar term arrived, the temperature in many areas began to get lower.

When the cold air from the south meets the gradually decaying warm and humid air, the rainfall will take away the heat on the ground and lower the surface temperature. Therefore, after the autumnal equinox, the weather will gradually turn cold, and the temperature difference at night will gradually widen. After the autumnal equinox, the direct point of the sun began to enter the southern hemisphere from the equator, and the northern hemisphere began to have shorter days and longer nights, and the day began to be shorter than the night in a day.

After the autumnal equinox, the days are getting shorter and shorter in the northern hemisphere, and the nights are getting longer and longer in the southern hemisphere. From the winter solstice, the day becomes longer and longer, but from the vernal equinox, the day is longer than the night, from the summer solstice, the day becomes shorter and shorter, but from the autumnal equinox, the day is shorter than the night.