Why is it so hot?

Electromagnetic waves and particle streams emitted by the sun into space. The solar radiation energy received by the earth is only 1/2 of the total radiation energy emitted by the sun into space, but it is the main energy source of the earth's atmospheric movement.

On the day of summer solstice, the sun directly reaches the northernmost point of the year, almost directly to the Tropic of Cancer (23 26' 28 "44 north latitude), and the daytime in the northern hemisphere is the longest, and the farther north it is, the longer it is. It is the longest day in a year in the northern hemisphere, and it takes about fourteen hours from sunrise to sunset in the south of China. Although the summer solstice has the longest day and the highest sun angle, it is not the hottest time of the year. Because, close to the surface of the heat, at this time still continue to save, did not reach the maximum time. As the saying goes, "Hot days are in dog days", and the real hot weather is calculated by summer solstice and beginning of autumn. From mid-July to mid-August, the temperature is the highest in all parts of the country, and the highest temperature in some areas can reach about 40℃.