Heavy snow is the 21st solar term among the 24 solar terms and the third solar term in winter. Douzhiren, the sun reaches 255 degrees in the yellow longitude, and the festival occurs from December 6th to 8th in the Gregorian calendar each year. Heavy snow, as the name suggests, has a large amount of snow. The ancients said, "The great are prosperous, and from here on, the snow is prosperous.". At this time, snow often falls heavily and has a wide range, hence the name "heavy snow". The heavy snow season marks the beginning of the sub month in the Ganzhi calendar, marking the official start of the mid winter season.
At this time, the lowest temperature in most areas of our country has dropped to 0 ℃ or below. Often, in areas where cold and warm air intersect at the forefront of strong cold air, heavy snow or even blizzards may occur. It can be seen that the heavy snow solar term represents the starting time and degree of heavy snow during this period. Like light snow, rain, and grain rain, it is a solar term that directly reflects precipitation.