Autumn is the thirteenth of the twenty-four solar terms, but also the first of the fall, autumn means precipitation, humidity, etc., at the turning point of the year, tends to decline or decrease; in nature, everything begins to grow from luxuriant tend to be mature.
Autumn does not mean that the hot weather is over, autumn is still in the summer heat period, not yet out of the summer, the second season of autumn (heat) before the summer, the weather is still very hot during early autumn. The so-called "hot in three volts", there is a "fall after a volt" said, after the fall there is at least "a volt" of hot weather.
According to the "three volts" projection method, "Autumn" this day is often still in the middle of the volts period, that is to say, the summer heat is not over, the real coolness is generally to the White Dew Festival after. The watershed of heat and cool is not in the fall season.