What is the meaning of the twenty-four solar terms?

Slight summer heat is a festival that reflects the change of temperature. Usually on July 7 or 8 of the Gregorian calendar. "Summer heat" is heat, and "small" is the degree of heat. Slight heat refers to the hot summer, but it is not the hottest time yet. As the saying goes, "a little summer is not hot, it is dog days."

Trees are shady and summer is hot. The average temperature in the south is about 26℃ in the light summer, which is already midsummer and quite hot, but it is not the hottest time yet. In mid-July all the year round, in the low-altitude valley area of southeastern South China, the concentration period of daily average temperature higher than 30℃ and daily maximum temperature higher than 35℃ can begin to appear, which is not conducive to heading and flowering of hybrid rice.

In addition to fully considering this factor in the layout in advance, corresponding remedial measures should be taken for those that have been planted. In the northern part of the northwest plateau, frost and snow can still be seen at this time, which is equivalent to the scene of early spring in South China.