What month is autumn?

Autumn, also known as autumn, is the third season of the year. The transition season from summer to winter is from September to 165438+ 10 in the northern hemisphere, from March to May in the southern hemisphere, and from the autumnal equinox to the winter solstice in astronomy. Meteorologists study phenology according to the following criteria: after the summer heat, the five-day average temperature is below 22 degrees for autumn, and it ends below 10 degrees.

The extended data autumnal equinox is a solar term representing seasonal changes. 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 waiting temperature in the southern region has generally dropped below 22℃, and it has 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. In the northern part of the northwest plateau, the daily minimum temperature has dropped below 0℃, and you can already see the magnificent snow scene flying all over the sky and the earth wrapped in silver.

After the autumnal equinox, rainfall in most parts of the south decreased significantly, and heavy rain and heavy rain rarely appeared. However, rainy days increase, rainy days are frequent, and the night rain rate is high. Li Shangyin, a famous poet in the Tang Dynasty, famously said, "It rains late in autumn pond", which vividly describes the climate characteristics of autumn rainy nights in the south.

It is rainy and humid in autumn in the south and Liangshan Prefecture, which has great influence on autumn harvest, autumn ploughing and autumn planting. It is necessary to grasp the sun, control soil moisture and prevent waterlogging, and do a good job in the quality and progress of Sanqiu production. At the same time, we should make full use of the meteorological conditions of rainy autumn and good soil moisture, seize the opportunity to do a good job in afforestation, and strive to improve the survival rate of saplings.

References:

Baidu Encyclopedia-Autumn