What are the characteristics of autumn?

Autumn is characterized by a bumper harvest, a gradual drop in temperature, a dry climate, a gradual withering of plants and a narrowing of the gap between day and night.

1. The temperature drops gradually: With the end of summer, the arrival of autumn marks the temperature drop. It is warm during the day and cool at night, so people need to wear thin coats or long-sleeved clothes.

2. Leaves change color: Autumn is the season when leaves change color. Due to the decrease of temperature and sunshine time, chlorophyll in leaves gradually decreases, revealing other colors, such as red, orange, yellow and brown, creating a beautiful autumn scenery.

3. Harvest season: Autumn is also a harvest season, and crops such as rice, wheat, apples and grapes are ripe for picking. People can enjoy all kinds of fresh fruits and vegetables.

4. Decrease of sunshine time: In autumn, sunshine time gradually decreases, with shorter daytime time and longer night time. This is also a remarkable feature of seasonal changes.

5, fallen leaves: With the arrival of autumn, leaves began to fall gradually. Trees reduce the yield of leaves in order to cope with the cold winter and prepare for new growth.

6. Mild weather: The weather in autumn is usually milder, drier and less rainy than that in summer and winter. This is a good time for people to keep fit and do outdoor activities.

Autumn is the harvest season, and many fruits ripen in autumn. Due to the reduction of sunshine time and the continuous invasion of cold air in the north, the temperature will drop significantly in autumn. As the temperature drops, the leaves of many perennial plants will gradually change color, wither and fall off, leaving only branches for winter.

Panicum miliaceum will come to the end of his life, wither and die. Beginning of autumn doesn't mean that the hot summer will be over. beginning of autumn is still in the heat period, and the heat will not come out until the second solar term in autumn, and the weather is still very hot in early autumn.

The so-called "heat is in three volts", according to the calculation method of "three volts", beginning of autumn is often still in the "three volts" period until the summer heat, so the weather is still very hot in early autumn, and it will not be really cool until after the Millennium solar term. The watershed of summer heat is in autumn, not at the turn of summer and autumn. The climate in autumn is divided into two stages, the early autumn is sultry, and it tends to be dry and cool after the Mid-Autumn Festival.

According to the average climate temperature of modern scholar Zhang Baokun, there are four seasons in a year. The index is that the average temperature is lower than 10℃ in winter, higher than 22℃ in summer, and the average temperature is 10-22℃ in spring and autumn respectively.

The standard of waiting for the average temperature in autumn adopted in meteorology is that after the summer heat, the average temperature is lower than 22℃ for five consecutive days, even if it enters autumn, it ends when the average temperature is lower than 10℃ and enters winter.