What does the first frost mean?

In the first frost growing season, the temperature dropped to 0℃ or below, which made plants suffer. Whether there is frost or not, it means that the temperature drops suddenly, and the surface temperature drops below 0℃, causing damage to crops and even death. It can be seen from the contour map of the average first frost day that frost can appear in the northeast of Xinjiang and the northeast of Inner Mongolia in early September:1Frost appears in the northeast, north of North China and most of the west in early October. How to reduce freezing injury is a common concern. Our meteorologists have been strengthening the monitoring and forecasting service of the first frost, so that the relevant departments can take defensive measures to reduce the losses caused by frost.