It gets cold in autumn.

Entering August also represents the arrival of autumn. In autumn, the altitude angle of the sun gradually decreases, and the temperature gradually decreases from heat. Autumn is one of the four seasons.

According to modern meteorology, autumn in north temperate zone is from August 23rd (summer) to165438+1October 20th (light snow). Autumn in the south temperate zone is from February 19 (rain in the northern hemisphere) to May 2 1 (xiaoman in the northern hemisphere). In China, traditionally, the "beginning of autumn" with 24 solar terms is the starting point of autumn and ends in the beginning of winter.

Extended data

In autumn, the cold air in the north is constantly invading, but its power is not very strong. Autumn weather often forms in northern China, and continuous autumn rain often appears in West China. The temperature will gradually drop in autumn, but it is generally slower than in winter. Due to the difference of dry and wet conditions, there will be cold and rainy weather conditions or dry and cool weather conditions in different regions.

In the cold late autumn, due to the large temperature difference between day and night, the water vapor transpiration during the day will condense at night, either dew or frost. In autumn, the direct point of the sun gradually moves south from the northern hemisphere, passes through the equator after the autumnal equinox, and the sun directly shines in the southern hemisphere. Seen from the northern hemisphere, the angle of the sun gradually becomes lower, and the gap between day and night becomes smaller. At the autumnal equinox, the length of day and night is equal.