When does the frost occur? Thank you~

Frost usually appears in autumn, winter and spring. During frost, the temperature drops sharply, and the surface temperature drops below 0℃, which damages crops and even causes death.

According to the different frost seasons, it can be divided into spring frost and autumn frost.

1, spring frost is also called late frost, that is, the frost that occurs after spring sowing crops are in seedling stage, fruit trees are in flowering stage and overwintering crops turn green. With the increase of temperature, the frequency and intensity of late frost gradually decrease, but the later it appears, the greater the harm to crops.

2. Autumn frost, also known as early frost, occurs when the autumn harvest crops are immature and the vegetables in the open field are not harvested. As the season goes on, the frequency and intensity of autumn frost increase gradually.

Extended data:

Do a good job in the defense of the first frost;

The first frost occurs in the early stage of crop maturity, which directly affects the yield and quality. Even if remedial measures are taken after the disaster, it is difficult to recover the losses. Therefore, in areas where the first frost is seriously harmful, we should choose cold-resistant and early-maturing varieties, reasonably adjust sowing date and strengthen field management to ensure that crops are fully mature before the frost comes.

The heat condition and the first frost in the later period of Northeast China are important factors to determine whether the crops can be fully filled and have high yield in the later period.

In addition to selecting suitable planting areas and varieties and adjusting sowing date, the methods to prevent freezing injury are mainly to seek advantages and avoid disadvantages, and to combine avoidance, resistance and prevention Smoking, mulching, irrigation, water spraying and burning heavy oil are often used.

In areas where frost has not yet appeared, effective measures should be taken to promote the maturity of crops in low-lying areas in order to reduce the yield loss caused by frost. Crops damaged by light frost can also be harvested later according to the weather conditions in the later period, so as to promote after-ripening and improve quality.

Baidu encyclopedia-frost

People's Daily Online-In the next 10 day, there will be three cold air streams in the north of China to prevent frost disaster.