When is the dog days of 20 13?

"Three volts" refers to the first, middle and last three volts, which is about mid-July to mid-August. After the summer solstice, although the days are getting shorter and the nights are getting longer, the days are longer than the nights in a day. Every day, the ground absorbs more heat than it emits, and the temperature near the ground is getting higher every day. During the "three volts" period, the heat absorbed by the ground is almost less than the heat emitted, and the weather is the hottest. After that, the heat absorbed by the ground began to be less than the heat emitted by the ground, and the temperature gradually decreased. Therefore, the hottest time of the year generally appears in the "dog days" from the summer solstice.

From summer to the third watch in the future, the first (10 day), the middle (10 ~ 20 days) and the last (after beginning of autumn 10 day) are the hottest days of the year.

The dog days of 20 13 began in July 13.